153 results on '"Ganesh A. Thakur"'
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2. Non-fragile synchronization of BAM neural networks with randomly occurring controller gain fluctuation
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Ganesh Kumar Thakur, Sudesh Kumar Garg, Tej Singh, M. Syed Ali, and Tarun Kumar Arora
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Computational Mathematics ,Applied Mathematics ,Modeling and Simulation ,General Medicine ,General Agricultural and Biological Sciences - Abstract
In this research, a non-fragile synchronization of bidirectional association memory (BAM) delayed neural networks is taken into consideration. The controller gain fluctuation seems in a very random manner, that obeys sure Bernoulli distributed noise sequences. Delay dependent criteria are derived to confirm the asymptotic stability of the BAM delayed neural networks. The non-fragile controller are often obtained by determination a collection of linear matrix inequalities (LMIs). A simulation example is used to demonstrate the efficiency of the developed control.
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- 2023
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3. Importance of reservoir simulation and early reservoir management for successful field development — Case study
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Zeinab Zargar and Ganesh C. Thakur
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General Energy - Published
- 2022
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4. Differential Activation and Desensitization States Promoted by Noncanonical α7 Nicotinic Acetylcholine Receptor Agonists
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Clare Stokes, Gisela Andrea Camacho-Hernandez, Ganesh A. Thakur, Xiaoxuan Wu, Palmer Taylor, and Roger L. Papke
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Pharmacology ,Molecular Medicine - Published
- 2022
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5. Adaptive event‐triggered pinning synchronization control for complex networks with random saturation subject to hybrid cyber‐attacks
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M. Syed Ali, M. Mubeen Tajudeen, Grienggrai Rajchakit, Bandana Priya, and Ganesh Kumar Thakur
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Control and Systems Engineering ,Signal Processing ,Electrical and Electronic Engineering - Published
- 2023
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6. An Efficient, Green Synthesis of Hemiaminals of Isatins using TBAF under Aqueous Reaction Media
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null Pramod B Thakur, null Rupashri K. Kadu, null Ganesh A. Thakur, and null Raghunath A. Katkar
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The synthesis of hemiaminals of isatin derivatives is described by the reaction of isatin with formaldehyde in the presence of TBAF in water at ambient temperature. The procedure is very simple, convenient, and efficient, which provides high yield of product. Additionally the method is applicable for both varieties of substituted isatins derivatives. Moreover, the environmentally benign nature of reaction media makes the procedure attractive alternative over earlier methods.
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- 2022
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7. pth moment exponential stability of memristor Cohen–Grossberg BAM neural networks with time-varying delays and reaction–diffusion
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Bhawna Dhupia, M. Syed Ali, Ganesh Kumar Thakur, Sumaya Sanober, and Bandana Priya
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Equilibrium point ,Moment (mathematics) ,Artificial neural network ,Exponential stability ,law ,Reaction–diffusion system ,General Physics and Astronomy ,Applied mathematics ,Memristor ,Differential (infinitesimal) ,Stability (probability) ,Mathematics ,law.invention - Abstract
In this paper, stability for a class of stochastic memristor Cohen–Grossberg BAM neural networks with time-varying delays and reaction–diffusion are considered. A set of novel sufficient conditions on p th moment exponential stability of the equilibrium point are investigated for the considered system. We constructed Lyapunov functional and utilized stochastic stability theory and It o ˆ ’s differential formula. Finally, two examples are provided to illustrate the effectiveness of the derived main results.
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- 2021
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8. Reliable controller for nonlinear multiagent system with additive time varying delay and nonlinear actuator faults
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Bandana Priya, M. Syed Ali, Syeda Asma Kauser, R. Agalya, and Ganesh Kumar Thakur
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Nonlinear system ,Control theory ,General Mathematics ,General Engineering ,Actuator ,Mathematics - Published
- 2021
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9. Pharmacological evaluation of enantiomerically separated positive allosteric modulators of cannabinoid 1 receptor, GAT591 and GAT593
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Asher L, Brandt, Sumanta, Garai, Ayat, Zagzoog, Dow P, Hurst, Lesley A, Stevenson, Roger G, Pertwee, Gregory H, Imler, Patricia H, Reggio, Ganesh A, Thakur, and Robert B, Laprairie
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Pharmacology ,Pharmacology (medical) - Abstract
Positive allosteric modulation of the type 1 cannabinoid receptor (CB1R) has substantial potential to treat both neurological and immune disorders. To date, a few studies have evaluated the structure-activity relationship (SAR) for CB1R positive allosteric modulators (PAMs). In this study, we separated the enantiomers of the previously characterized two potent CB1R ago-PAMs GAT591 and GAT593 to determine their biochemical activity at CB1R. Separating the enantiomers showed that the R-enantiomers (GAT1665 and GAT1667) displayed mixed allosteric agonist-PAM activity at CB1R while the S-enantiomers (GAT1664 and GAT1666) showed moderate activity. Furthermore, we observed that the R and S-enantiomers had distinct binding sites on CB1R, which led to their distinct behavior both in vitro and in vivo. The R-enantiomers (GAT1665 and GAT1667) produced ago-PAM effects in vitro, and PAM effects in the in vivo behavioral triad, indicating that the in vivo activity of these ligands may occur via PAM rather than agonist-based mechanisms. Overall, this study provides mechanistic insight into enantiospecific interaction of 2-phenylindole class of CB1R allosteric modulators, which have shown therapeutic potential in the treatment of pain, epilepsy, glaucoma, and Huntington’s disease.
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- 2022
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10. Inhibition of PSD95‐nNOS protein–protein interactions decreases morphine reward and relapse vulnerability in rats
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Idaira Oliva, Shahin A. Saberi, Claudia Rangel‐Barajas, Vishakh Iyer, Kendra D. Bunner, Yvonne Y. Lai, Pushkar M. Kulkarni, Sumanta Garai, Ganesh A. Thakur, Jonathon D. Crystal, George V. Rebec, and Andrea G. Hohmann
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Pharmacology ,Psychiatry and Mental health ,Morphine ,Reward ,Recurrence ,Animals ,Medicine (miscellaneous) ,Nitric Oxide Synthase Type I ,Disks Large Homolog 4 Protein ,Receptors, N-Methyl-D-Aspartate ,Nucleus Accumbens ,Rats - Abstract
Glutamate signalling through the N-methyl-d-aspartate receptor (NMDAR) activates the enzyme neuronal nitric oxide synthase (nNOS) to produce the signalling molecule nitric oxide (NO). We hypothesized that disruption of the protein-protein interaction between nNOS and the scaffolding protein postsynaptic density 95 kDa (PSD95) would block NMDAR-dependent NO signalling and represent a viable therapeutic route to decrease opioid reward and relapse-like behaviour without the unwanted side effects of NMDAR antagonists. We used a conditioned place preference (CPP) paradigm to evaluate the impact of two small-molecule PSD95-nNOS inhibitors, IC87201 and ZL006, on the rewarding effects of morphine. Both IC87201 and ZL006 blocked morphine-induced CPP at doses that lacked intrinsic rewarding or aversive properties. Furthermore, in vivo fast-scan cyclic voltammetry (FSCV) was used to ascertain the impact of ZL006 on morphine-induced increases in dopamine (DA) efflux in the nucleus accumbens shell (NAc shell) evoked by electrical stimulation of the medial forebrain bundle (MFB). ZL006 attenuated morphine-induced increases in DA efflux at a dose that did not have intrinsic effects on DA transmission. We also employed multiple intravenous drug self-administration approaches to examine the impact of ZL006 on the reinforcing effects of morphine. Interestingly, ZL006 did not alter acquisition or maintenance of morphine self-administration, but reduced lever pressing in a morphine relapse test after forced abstinence. Our results provide behavioural and neurochemical support for the hypothesis that inhibition of PSD95-nNOS protein-protein interactions decreases morphine reward and relapse-like behaviour, highlighting a previously unreported application for these novel therapeutics in the treatment of opioid addiction.
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- 2022
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11. Negative allosteric modulation of CBsub1/subcannabinoid receptor signaling suppresses opioid-mediated reward
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Vishakh Iyer, Claudia Rangel-Barajas, Taylor J. Woodward, Abhijit Kulkarni, Lucas Cantwell, Jonathon D. Crystal, Ken Mackie, George V. Rebec, Ganesh A. Thakur, and Andrea G. Hohmann
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Pharmacology ,Male ,Analgesics, Opioid ,Mice, Knockout ,Mice ,Reward ,Morphine ,Receptor, Cannabinoid, CB1 ,Dopamine ,Animals ,Receptors, Cannabinoid ,Article - Abstract
Blockade of cannabinoid type 1 (CBsub1/sub)-receptor signaling decreases the rewarding properties of many drugs of abuse and has been proposed as an anti-addiction strategy. However, psychiatric side-effects limit the clinical potential of orthosteric CBsub1/subantagonists. Negative allosteric modulators (NAMs) represent a novel and indirect approach to attenuate CBsub1/subsignaling by decreasing affinity and/or efficacy of CBsub1/subligands. We hypothesized that a CBsub1/sub-NAM would block opioid reward while avoiding the unwanted effects of orthosteric CBsub1/subantagonists. GAT358, a CBsub1/sub-NAM, failed to elicit cardinal signs of direct CBsub1/subactivation or inactivation when administered by itself. GAT358 decreased catalepsy and hypothermia but not antinociception produced by the orthosteric CBsub1/subagonist CP55,940, suggesting that a CBsub1/sub-NAM blocked cardinal signs of CBsub1/subactivation. Next, GAT358 was evaluated using in vivo assays of opioid-induced dopamine release and reward in male rodents. In the nucleus accumbens shell, a key component of the mesocorticolimbic reward pathway, morphine increased electrically-evoked dopamine efflux and this effect was blocked by a dose of GAT358 that lacked intrinsic effects on evoked dopamine efflux. Moreover, GAT358 blocked morphine-induced reward in a conditioned place preference (CPP) assay without producing reward or aversion alone. GAT358-induced blockade of morphine CPP was also occluded by GAT229, a CBsub1/subpositive allosteric modulator (CBsub1/sub-PAM), and absent in CBsub1/sub-knockout mice. Finally, GAT358 also reduced oral oxycodone (but not water) consumption in a two-bottle choice paradigm. Our results support the therapeutic potential of CBsub1/sub-NAMs as novel drug candidates aimed at preventing opioid reward and treating opioid abuse while avoiding unwanted side-effects.
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- 2022
12. Finite-time stability analysis of fractional-order memristive fuzzy cellular neural networks with time delay and leakage term
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M. Syed Ali, Ganesh Kumar Thakur, Sumit Saroha, Govindasamy Narayanan, and Bandana Priya
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Hölder's inequality ,Numerical Analysis ,General Computer Science ,Bernoulli's inequality ,Computer science ,Applied Mathematics ,Stability (learning theory) ,Memristor ,Theoretical Computer Science ,Term (time) ,law.invention ,Differential inclusion ,Control theory ,law ,Modeling and Simulation ,Order (group theory) ,Leakage (electronics) - Abstract
In this paper, we investigate finite-time stability analysis of fractional-order memristive fuzzy cellular neural networks(MFFCNNs) with time delay and leakage term. MFFCNNs are formulated by virtue of differential inclusion and set-valued map theories. By using generalized Bernoulli inequality and Holder inequality, we derived some new sufficient conditions of finite-time stability for the proposed system. Finally two numerical examples are given to show the effectiveness of the proposed approach.
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- 2021
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13. Stability analysis of quasi one-sided Lipschitz non-linear multi-agent system via sampled data control subject to directed switching topology
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R. Agalya, M. Syed Ali, Ganesh Kumar Thakur, Banadana Priya, and Vineet Shekher
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0209 industrial biotechnology ,Control and Optimization ,Computer science ,Applied Mathematics ,Multi-agent system ,Stability (learning theory) ,Topology (electrical circuits) ,02 engineering and technology ,Topology ,Lipschitz continuity ,Nonlinear system ,020901 industrial engineering & automation ,Control and Systems Engineering ,One sided ,Data control ,Subject (grammar) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing - Abstract
This paper is concerned with the problem of stability and consensus of non-linear multi-agent system by utilizing the sampled-data control. The innovative part of this paper is that the nonlinearity of this class of nonlinear systems is considered to satisfy a quasi one-sided Lipschitz condition. Communication among agents are assumed to be a switching directed graph. The principle target of this paper is to design a sampled data controller such that for all permissible uncertainties, the resulting closed-loop system is stable in the sense of mean square. For this reason, through the development of an appropriate Lyapunov–Krasovskii functional with dual integral terms and usage of Kronecker product properties alongside the matrix inequality techniques, a new set of stability and consensus conditions for the prescribed system is obtained in the form of a linear matrix inequality, which can be easily solved by the well-known effective numerical programming. Finally numerical examples are given to show the validity of the proposed hypothetical results.
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- 2021
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14. Novel Functionalized Cannabinoid Receptor Probes: Development of Exceptionally Potent Agonists
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Yiran Wu, Keith A. Sharkey, Zhi-Jie Liu, Tian Hua, Alexandros Makriyannis, Catherine M. Keenan, Nikolai Zvonok, Ganesh A. Thakur, Christina A Brust, Travis W. Grim, Simiao Wu, Spyros P. Nikas, Shan Jiang, Fei Tong, Jimit Girish Raghav, Christos Iliopoulos-Tsoutsouvas, Laura M. Bohn, and Jo-Hao Ho
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Male ,Cannabinoid receptor ,Stereochemistry ,CHO Cells ,Ligands ,01 natural sciences ,Receptor, Cannabinoid, CB2 ,Mice ,03 medical and health sciences ,Cricetulus ,Receptor, Cannabinoid, CB1 ,In vivo ,Drug Discovery ,Animals ,Humans ,030304 developmental biology ,Binding affinities ,Cannabinoid Receptor Agonists ,Analgesics ,0303 health sciences ,Cannabinoids ,Chemistry ,Extramural ,Ligand (biochemistry) ,In vitro ,Rats ,3. Good health ,0104 chemical sciences ,Molecular Docking Simulation ,010404 medicinal & biomolecular chemistry ,Electrophile ,Molecular Medicine ,Locomotion ,Body Temperature Regulation - Abstract
We report the development of novel cannabinergic probes that can stabilize the cannabinoid receptors (CBRs) through tight binding interactions. Ligand design involves the introduction of select groups at a judiciously chosen position within the classical hexahydrocannabinol template (monofunctionalized probes). Such groups include the electrophilic isothiocyanato, the photoactivatable azido, and the polar cyano moieties. These groups can also be combined to produce bifunctionalized probes potentially capable of interacting at two distinct sites within the CBR-binding domains. These novel compounds display remarkably high binding affinities for CBRs and are exceptionally potent agonists. A key ligand (27a, AM11245) exhibits exceptionally high potency in both in vitro and in vivo assays and was designated as "megagonist," a property attributed to its tight binding profile. By acting both centrally and peripherally, 27a distinguishes itself from our previously reported "megagonist" AM841, whose functions are restricted to the periphery.
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- 2021
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15. Differential Activation and Desensitization States Promoted by Noncanonical
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Clare, Stokes, Gisela Andrea, Camacho-Hernandez, Ganesh A, Thakur, Xiaoxuan, Wu, Palmer, Taylor, and Roger L, Papke
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Xenopus laevis ,Sulfonamides ,Epitopes ,Pyrimidines ,alpha7 Nicotinic Acetylcholine Receptor ,Allosteric Regulation ,Quinolines ,Animals ,Humans ,Calcium ,Nicotinic Agonists ,Receptors, Nicotinic ,Acetylcholine - Abstract
A series of dipicolyl amine pyrimidines (DPPs) were previously identified as potential
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- 2022
16. Antipsychotic potential of the type 1 cannabinoid receptor positive allosteric modulator GAT211: preclinical in vitro and in vivo studies
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Robert B. Laprairie, Sumanta Garai, Andrew J. Roebuck, John G. Howland, Eileen M. Denovan-Wright, Quentin Greba, Dan L. McElroy, Gavin A. Scott, and Ganesh A. Thakur
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Pharmacology ,Startle response ,Allosteric modulator ,Cannabinoid receptor ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Open field ,3. Good health ,030227 psychiatry ,03 medical and health sciences ,0302 clinical medicine ,Dopamine receptor D2 ,mental disorders ,Medicine ,NMDA receptor ,business ,Antipsychotic ,030217 neurology & neurosurgery ,Prepulse inhibition - Abstract
Antipsychotics help alleviate the positive symptoms associated with schizophrenia; however, their debilitating side effects have spurred the search for better treatment options. Novel compounds can be screened for antipsychotic potential in neuronal cell cultures and following acute N-methyl-D-aspartate (NMDA) receptor blockade with non-competitive antagonists such as MK-801 in rodent behavioral models. Given the known interactions between NMDA receptors and type 1 cannabinoid receptors (CB1R), compounds that modulate CB1Rs may have therapeutic potential for schizophrenia. This study assessed whether the CB1R positive allosteric modulator GAT211, when compared to ∆9-tetrahydrocannabinol (THC), has potential to reduce psychiatric behavioral phenotypes following acute MK-801 treatment in rats, and block hyperdopaminergic signalling associated with those behaviors. The effects of GAT211 and THC on cellular signaling were compared in Neuro2a cells, and behavioral effects of GAT211 and THC on altered locomotor activity and prepulse inhibition of the acoustic startle response caused by acute MK-801 treatment were assessed in male, Long Evans rats. GAT211 limited dopamine D2 receptor-mediated extracellular regulated kinase (ERK) phosphorylation in Neuro2a cells, whereas THC did not. As expected, acute MK-801 (0.15 mg/kg) produced a significant increase in locomotor activity and impaired PPI. GAT211 treatment alone (0.3–3.0 mg/kg) dose-dependently reduced locomotor activity and the acoustic startle response. GAT211 (3.0 mg/kg) also prevented hyperlocomotion caused by MK-801 but did not significantly affect PPI impairments. Taken together, these findings support continued preclinical research regarding the usefulness of CB1R positive allosteric modulators as antipsychotics.
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- 2021
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17. Stability analysis of stochastic fractional-order competitive neural networks with leakage delay
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Bandana Priya, Syeda Asma Kauser, M. Hymavathi, M. Syed Ali, and Ganesh Kumar Thakur
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Class (set theory) ,Artificial neural network ,Stochastic process ,lcsh:Mathematics ,General Mathematics ,leakage ,Fixed point ,lcsh:QA1-939 ,Stability (probability) ,fractional order ,Set (abstract data type) ,Applied mathematics ,stochastic ,Uniqueness ,competitive neural networks ,Mathematics ,Leakage (electronics) - Abstract
This article, we explore the stability analysis of stochastic fractional-order competitive neural networks with leakage delay. The main objective of this paper is to establish a new set of sufficient conditions, which is for the uniform stability in mean square of such stochastic fractional-order neural networks with leakage. Specifically, the presence and uniqueness of arrangements and stability in mean square for a class of stochastic fractional-order neural systems with delays are concentrated by using Cauchy-Schwartz inequality, Burkholder-Davis-Gundy inequality, Banach fixed point principle and stochastic analysis theory, respectively. Finally, four numerical recreations are given to confirm the hypothetical discoveries.
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- 2021
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18. ℋ∞/passive non-fragile synchronisation of Markovian jump stochastic complex dynamical networks with time-varying delays
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M. Syed Ali, M. Usha, Nallappan Gunasekaran, Ganesh Kumar Thakur, and Oh-Min Kwon
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Coupling ,Markovian jump ,Control and Systems Engineering ,Control theory ,Computer science ,Synchronization ,Computer Science Applications ,Theoretical Computer Science ,Markovian jumping - Abstract
This paper deals with the problem of /passive non-fragile synchronisation for a class of complex dynamical networks subject to Markovian jumping time-varying coupling delays. Gain variation is repr...
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- 2020
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19. Progress in the Synthesis of Oxindole‐Naphthoquinone Molecular Hybrid Scaffolds: A Concise Review
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Vishwanath R. Patil, Ganesh Anant Thakur, Pramod B. Thakur, and Rupashri K. Kadu
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chemistry.chemical_compound ,chemistry ,Isatin ,Oxindole ,General Chemistry ,Combinatorial chemistry ,Naphthoquinone - Published
- 2020
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20. Allosterically Potentiated α7 Nicotinic Acetylcholine Receptors: Reduced Calcium Permeability and Current-Independent Control of Intracellular Calcium
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Douglas R. Miller, Roger L. Papke, Sumanta Garai, Lucas Cantwell, Ganesh A. Thakur, Clare Stokes, and Habibeh Khoshbouei
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0301 basic medicine ,Cell Membrane Permeability ,Patch-Clamp Techniques ,alpha7 Nicotinic Acetylcholine Receptor ,chemistry.chemical_element ,Calcium ,Piperazines ,Calcium in biology ,Xenopus laevis ,03 medical and health sciences ,0302 clinical medicine ,Allosteric Regulation ,medicine ,Animals ,Humans ,Channel blocker ,Reversal potential ,Acetylcholine receptor ,Pharmacology ,Calcium metabolism ,Sulfonamides ,Phenylpropionates ,Chemistry ,Articles ,Acetylcholine ,HEK293 Cells ,030104 developmental biology ,Nicotinic agonist ,Oocytes ,Quinolines ,Biophysics ,Molecular Medicine ,Allosteric Site ,030217 neurology & neurosurgery ,medicine.drug - Abstract
The currents of α7 nicotinic acetylcholine receptors activated by acetylcholine (ACh) are brief. The channel has high permeability to calcium relative to monovalent cations and shows inward rectification. It has been previously noted that in the presence of positive allosteric modulators (PAMs), currents through the channels of α7 receptors differ from normal α7 currents both in sensitivity to specific channel blockers and their current-voltage (I-V) relationships, no longer showing inward rectification. Linear I-V functions are often associated with channels lacking calcium permeability, so we measured the I-V functions of α7 receptors activated by ACh when PAMs were bound to the allosteric binding site in the transmembrane domain. Currents were recorded in chloride-free Ringer’s solution with low or high concentrations of extracellular calcium to determine the magnitude of the reversal potential shift in the two conditions as well as the I-V relationships. ACh-evoked currents potentiated by the allosteric agonist–PAMs (ago-PAMs) (3aR,4S,9bS)-4-(4-bromophenyl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinoline-8-sulfonamide (GAT107) and 3-(3,4-difluorophenyl)-N-(1-(6-(4-(pyridin-2-yl)piperazin-1-yl)pyrazin-2-yl)ethyl)propenamide (B-973B) showed reduced inward rectification and calcium-dependent reversal potential shifts decreased by 80%, and 50%, respectively, compared with currents activated by ACh alone, indicative of reduced calcium permeability. Currents potentiated by 3a,4,5,9b-tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide were also linear and showed no calcium-dependent reversal potential shifts. The ago-PAMs GAT-107 and B-973B stimulated increases in intracellular calcium in stably transfected HEK293 cells. However, these calcium signals were delayed relative to channel activation produced by these agents and were insensitive to the channel blocker mecamylamine. Our results indicate that, although allosterically activated α7 nicotinic ACh receptor may affect intracellular calcium levels, such effects are not likely due to large channel-dependent calcium influx. SIGNIFICANCE STATEMENT: Positive allosteric modulators (PAMs) of α7 nicotinic acetylcholine receptor can increase channel activation by two or more orders of magnitude, raising the concern that, due to the relatively high calcium permeability of α7 receptors activated by acetylcholine alone, such efficacious PAMs may have cytotoxic side effects. We show that PAMs alter the ion conduction pathway and, in general, reduce the calcium permeability of the channels. This supports the hypothesis that α7 effects on intracellular calcium may be independent of channel-mediated calcium influx.
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- 2020
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21. Synthesis, Spectral Characterization and Antibacterial Studies of Mixed Ligand La(III) and Ce(III) Complexes Derived From 1-nitroso-2-naphthol and Some Amino acids
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Pramod Bhagawan Thakur, Ganesh Anant Thakur, and Uttam Narayan Dhaigude
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Green chemistry ,chemistry.chemical_classification ,biology ,Supramolecular chemistry ,Evisa ,General Chemistry ,biology.organism_classification ,Biochemistry ,Medicinal chemistry ,Coordination complex ,Amino acid ,chemistry ,GEOBASE ,FLUIDEX ,Drug Discovery ,Theoretical chemistry ,Environmental Chemistry - Published
- 2020
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22. Differing Activity Profiles of the Stereoisomers of 2,3,5,6TMP-TQS, a Putative Silent Allosteric Modulator of α7 nAChR
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Sumanta Garai, Roger L. Papke, Clare Stokes, Khalil A. Abboud, Nicole A. Horenstein, Arthur D. Zimmerman, and Ganesh A. Thakur
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0301 basic medicine ,Pharmacology ,Allosteric modulator ,Chemistry ,Stereochemistry ,In silico ,Mutant ,Allosteric regulation ,Antagonist ,Stereoisomerism ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Molecular Medicine ,Enantiomer ,Binding site ,030217 neurology & neurosurgery - Abstract
Many synthetic compounds to which we attribute specific activities are produced as racemic mixtures of stereoisomers, and it may be that all the desired activity comes from a single enantiomer. We have previously shown this to be the case with the α7 nicotinic acetylcholine receptor positive allosteric modulator (PAM) 3a,4,5,9b-Tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS) and the α7 ago-PAM 4BP-TQS. Cis-trans-4-(2,3,5,6-tetramethylphenyl)-3a,4,5,9b-te-trahydro-3H-cyclopenta[c]quinoline-8-sulfonamide (2,3,5,6TMP-TQS), previously published as a "silent allosteric modulator" and an antagonist of α7 allosteric activation, shares the same scaffold with three chiral centers as the aforementioned compounds. We isolated the enantiomers of 2,3,5,6TMP-TQS and determined that the (-) isomer was a significantly better antagonist than the (+) isomer of the allosteric activation of both wild-type α7 and the nonorthosterically activatible C190A α7 mutant by the ago-PAM GAT107 (the active isomer of 4BP-TQS). In contrast, (+)2,3,5,6TMP-TQS proved to be an α7 PAM. (-)2,3,5,6TMP-TQS was shown to antagonize the allosteric activation of α7 by the structurally unrelated ago-PAM B-973B as well as the allosteric activation of the TQS-sensitive α4β2L15'M mutant. In silico docking of 2,3,5,6TMP-TQS in the putative allosteric activation binding site suggested a specific interaction of the (-) enantiomer with α7T106, and allosteric activation of α7T106 mutants was not inhibited by (-)2,3,5,6TMP-TQS, confirming the importance of this interaction and supporting the model of the allosteric binding site. Comparisons and contrasts between 2,3,5,6TMP-TQS isomers and active and inactive enantiomers of other TQS-related compounds identify the orientation of the cyclopentenyl ring to the plane of the core quinoline to be a crucial determinate of PAM activity. SIGNIFICANCE STATEMENT: Many synthetic ligands are in use as racemic preparations. We show that one enantiomer of the TQS analog Cis-trans-4-(2,3,5,6-tetramethylphenyl)-3a,4,5,9b-te-trahydro-3H-cyclopenta[c]quinoline-8-sulfonamide, originally reported to lack activity when used as a racemic preparation, is an α7 nicotinic acetylcholine receptor positive allosteric modulator (PAM). The other enantiomer is not a PAM, but it is an effective allosteric antagonist. In silico studies and structural comparisons identify essential elements of both the allosteric ligands and receptor binding sites important for these allosteric activities.
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- 2020
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23. <scp>Cu</scp> ‐Assisted Cyanation Reactions
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Ganesh A. Thakur and Sumanta Garai
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chemistry ,chemistry.chemical_element ,Cyanation ,Combinatorial chemistry ,Copper ,Catalysis - Published
- 2020
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24. The small molecule GAT1508 activates brain-specific GIRK1/2 channel heteromers and facilitates conditioned fear extinction in rodents
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Yuchen Yang, Lucas Cantwell, Diomedes E. Logothetis, Erik T. Dustrude, Leigh D. Plant, Anantha Shekhar, Ganesh A. Thakur, Takeharu Kawano, Dimitris Gazgalis, Stephanie D. Fitz, Sami F. Noujaim, Yu Xu, Andrei I. Molosh, and Sumanta Garai
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Phosphatidylinositol 4,5-Diphosphate ,0301 basic medicine ,Allosteric modulator ,Xenopus ,Motor Activity ,Ligands ,Biochemistry ,Protein Structure, Secondary ,Extinction, Psychological ,Small Molecule Libraries ,03 medical and health sciences ,Cognition ,Neurobiology ,Allosteric Regulation ,medicine ,Animals ,Humans ,Homomeric ,Heart Atria ,G protein-coupled inwardly-rectifying potassium channel ,Phosphorylation ,Molecular Biology ,Binding Sites ,Behavior, Animal ,030102 biochemistry & molecular biology ,Chemistry ,Activator (genetics) ,Myocardium ,Phenylurea Compounds ,Brain ,Fear ,Cell Biology ,Amygdala ,Small molecule ,Potassium channel ,Mice, Inbred C57BL ,Protein Subunits ,Electrophysiology ,HEK293 Cells ,030104 developmental biology ,medicine.anatomical_structure ,G Protein-Coupled Inwardly-Rectifying Potassium Channels ,Organ Specificity ,Mutation ,Pyrazoles ,Ion Channel Gating ,Neuroscience ,Basolateral amygdala - Abstract
G-protein–gated inwardly-rectifying K(+) (GIRK) channels are targets of G(i/o)-protein–signaling systems that inhibit cell excitability. GIRK channels exist as homotetramers (GIRK2 and GIRK4) or heterotetramers with nonfunctional homomeric subunits (GIRK1 and GIRK3). Although they have been implicated in multiple conditions, the lack of selective GIRK drugs that discriminate among the different GIRK channel subtypes has hampered investigations into their precise physiological relevance and therapeutic potential. Here, we report on a highly-specific, potent, and efficacious activator of brain GIRK1/2 channels. Using a chemical screen and electrophysiological assays, we found that this activator, the bromothiophene-substituted small molecule GAT1508, is specific for brain-expressed GIRK1/2 channels rather than for cardiac GIRK1/4 channels. Computational models predicted a GAT1508-binding site validated by experimental mutagenesis experiments, providing insights into how urea-based compounds engage distant GIRK1 residues required for channel activation. Furthermore, we provide computational and experimental evidence that GAT1508 is an allosteric modulator of channel–phosphatidylinositol 4,5-bisphosphate interactions. Through brain-slice electrophysiology, we show that subthreshold GAT1508 concentrations directly stimulate GIRK currents in the basolateral amygdala (BLA) and potentiate baclofen-induced currents. Of note, GAT1508 effectively extinguished conditioned fear in rodents and lacked cardiac and behavioral side effects, suggesting its potential for use in pharmacotherapy for post-traumatic stress disorder. In summary, our findings indicate that the small molecule GAT1508 has high specificity for brain GIRK1/2 channel subunits, directly or allosterically activates GIRK1/2 channels in the BLA, and facilitates fear extinction in a rodent model.
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- 2020
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25. GAT107-mediated α7 nicotinic acetylcholine receptor signaling attenuates inflammatory lung injury and mortality in a mouse model of ventilator-associated pneumonia by alleviating macrophage mitochondrial oxidative stress via reducing MnSOD-S-glutathionylation
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Alex G. Gauthier, Mosi Lin, Sidorela Zefi, Abhijit Kulkarni, Ganesh A. Thakur, Charles R. Ashby, and Lin L. Mantell
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Organic Chemistry ,Clinical Biochemistry ,Biochemistry - Published
- 2023
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26. Retracted: Dissipative‐based synchronization of Markovian jumping complex dynamical networks with additive time‐varying delays, reaction‐diffusion terms, uncertainties, and sampled‐data control
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M. Usha, Syeda Asma Kauser, M. Syed Ali, Ganesh Kumar Thakur, and Bandana Priya
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General Mathematics ,Data control ,Synchronization (computer science) ,Reaction–diffusion system ,General Engineering ,Dissipative system ,Statistical physics ,Mathematics ,Markovian jumping - Published
- 2021
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27. Peripherally administered cannabinoid receptor 2 (CB
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Jenny L, Wilkerson, Lauren B, Alberti, Ganesh A, Thakur, Alexandros, Makriyannis, and Erin D, Milligan
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Cannabinoid Receptor Agonists ,Mice, Knockout ,Receptor, Cannabinoid, CB2 ,Mice ,Spinal Cord ,Chromones ,Hyperalgesia ,Ganglia, Spinal ,Glial Fibrillary Acidic Protein ,Animals ,TRPV Cation Channels ,Chemokine CCL2 - Abstract
The transient receptor potential (TRP) superfamily of cation channels, of which the TRP vanilloid type 1 (TRPV1) receptor plays a critical role in inflammatory and neuropathic pain, is expressed on nociceptors and spinal cord dorsal horn neurons. TRPV1 is also expressed on spinal astrocytes and dorsal root ganglia (DRG) satellite cells. Agonists of the cannabinoid type 2 receptor (CB
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- 2021
28. A novel computation for predicting time series using fuzzy logical distance connectivity function and visibility graph theory
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Bandana Priya and Ganesh Kumar Thakur
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Computational Mathematics ,Computational Theory and Mathematics ,Series (mathematics) ,Computer science ,Computation ,Visibility graph ,Function (mathematics) ,Fuzzy logic ,Algorithm - Published
- 2020
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29. Identification of CB1 Receptor Allosteric Sites Using Force-Biased MMC Simulated Annealing and Validation by Structure–Activity Relationship Studies
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Ganesh A. Thakur, Sumanta Garai, Patricia H. Reggio, Dow P. Hurst, Peter C Schaffer, and Pushkar M. Kulkarni
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Agonist ,Cannabinoid receptor ,Allosteric modulator ,010405 organic chemistry ,Chemistry ,medicine.drug_class ,Organic Chemistry ,Allosteric regulation ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Drug development ,Drug Discovery ,medicine ,Biophysics ,Structure–activity relationship ,Binding site ,Intracellular - Abstract
[Image: see text] Positive allosteric modulation of the cannabinoid 1 receptor (CB1R) has demonstrated distinct therapeutic advantages that address several limitations associated with orthosteric agonism and has opened a promising therapeutic avenue for further drug development. To advance the development of CB1R positive allosteric modulators, it is important to understand the molecular architecture of CB1R allosteric site(s). The goal of this work was to use Force-Biased MMC Simulated Annealing to identify binding sites for GAT228 (R), a partial allosteric agonist, and GAT229 (S), a positive allosteric modulator (PAM) at the CB1R. Our studies suggest that GAT228 binds in an intracellular (IC) TMH1–2–4 exosite that would allow this compound to act as a CB1 allosteric agonist as well as a CB1 PAM. In contrast, GAT229 binds at the extracellular (EC) ends of TMH2/3, just beneath the EC1 loop. At this site, this compound can act as CB1 PAM only. Finally, these results were successfully validated through the synthesis and biochemical evaluation of a focused library of compounds.
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- 2019
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30. Heteromeric Neuronal Nicotinic Acetylcholine Receptors with Mutant β Subunits Acquire Sensitivity to α7-Selective Positive Allosteric Modulators
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Khalil A. Abboud, Clare Stokes, Nicole A. Horenstein, Abhijit R. Kulkarni, Roger L. Papke, Sumanta Garai, Colleen M. Noviello, Ryan E. Hibbs, Ganesh A. Thakur, and Lucas Cantwell
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Models, Molecular ,0301 basic medicine ,alpha7 Nicotinic Acetylcholine Receptor ,Allosteric regulation ,Mutant ,03 medical and health sciences ,Neuropharmacology ,0302 clinical medicine ,Allosteric Regulation ,medicine ,Animals ,Humans ,Homomeric ,Amino Acid Sequence ,Protein Structure, Quaternary ,Receptor ,Acetylcholine receptor ,Neurons ,Pharmacology ,Chemistry ,Cell biology ,Protein Subunits ,Transmembrane domain ,030104 developmental biology ,Nicotinic agonist ,Mutation ,Molecular Medicine ,Protein Multimerization ,030217 neurology & neurosurgery ,Acetylcholine ,medicine.drug - Abstract
Homomeric α7 nicotinic acetylcholine receptors (nAChR) have an intrinsically low probability of opening that can be overcome by α7-selective positive allosteric modulators (PAMs), which bind at a site involving the second transmembrane domain (TM2). Mutation of a methionine that is unique to α7 at the 15′ position of TM2 to leucine, the residue in most other nAChR subunits, largely eliminates the activity of such PAMs. We tested the effect of the reverse mutation (L15′M) in heteromeric nAChR receptors containing α4 and β2, which are the nAChR subunits that are most abundant in the brain. Receptors containing these mutations were found to be strongly potentiated by the α7 PAM 3a,4,5,9b-tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS) but insensitive to the alternative PAM 1-(5-chloro-2,4-dimethoxyphenyl)-3-(5-methylisoxazol-3-yl)-urea. The presence of the mutation in the β2 subunit was necessary and sufficient for TQS sensitivity. The primary effect of the mutation in the α4 subunit was to reduce responses to acetylcholine applied alone. Sensitivity to TQS required only a single mutant β subunit, regardless of the position of the mutant β subunit within the pentameric complex. Similar results were obtained when β2L15′M was coexpressed with α2 or α3 and when the L15′M mutation was placed in β4 and coexpressed with α2, α3, or α4. Functional receptors were not observed when β1L15′M subunits were coexpressed with other muscle nAChR subunits. The unique structure-activity relationship of PAMs and the α4β2L15′M receptor compared with α7 and the availability of high-resolution α4β2 structures may provide new insights into the fundamental mechanisms of nAChR allosteric potentiation. SIGNIFICANCE STATEMENT Heteromeric neuronal nAChRs have a relatively high initial probability of channel activation compared to receptors that are homomers of α7 subunits but are insensitive to PAMs, which greatly increase the open probability of α7 receptors. These features of heteromeric nAChR can be reversed by mutation of a single residue present in all neuronal heteromeric nAChR subunits to the sequence found in α7. Specifically, the mutation of the TM2 15′ leucine to methionine in α subunits reduces heteromeric receptor channel activation, while the same mutation in neuronal β subunits allows heteromeric receptors to respond to select α7 PAMs. The results indicate a key role for this residue in the functional differences in the two main classes of neuronal nAChRs.
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- 2019
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31. Positive allosteric modulation of the type 1 cannabinoid receptor reduces the signs and symptoms of Huntington's disease in the R6/2 mouse model
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Amina M. Bagher, Ganesh A. Thakur, Robert B. Laprairie, Melanie E. M. Kelly, Eileen M. Denovan-Wright, Christopher J. Sinal, Elizabeth A. Cairns, Pushkar M. Kulkarni, Adel Zrein, and Jillian L. Rourke
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Male ,0301 basic medicine ,Agonist ,Indoles ,Allosteric modulator ,Cannabinoid receptor ,Cell Survival ,medicine.drug_class ,medicine.medical_treatment ,Allosteric regulation ,Gene Expression ,Mice, Transgenic ,Motor Activity ,Pharmacology ,Article ,Mice ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Allosteric Regulation ,Receptor, Cannabinoid, CB1 ,Huntington's disease ,medicine ,Animals ,Cannabinoid Receptor Agonists ,business.industry ,Neurodegeneration ,medicine.disease ,Endocannabinoid system ,Corpus Striatum ,3. Good health ,Disease Models, Animal ,Huntington Disease ,030104 developmental biology ,Disease Progression ,lipids (amino acids, peptides, and proteins) ,Cannabinoid ,business ,030217 neurology & neurosurgery - Abstract
Huntington’s disease (HD) is an inherited progressive neurodegenerative disease characterized by motor, cognitive, and behavioural changes. One of the earliest changes to occur in HD is a reduction in cannabinoid 1 receptor (CB(1)) levels in the striatum, which is strongly correlated with HD pathogenesis. CB(1) positive allosteric modulators (PAM) enhance receptor affinity for, and efficacy of activation by, orthosteric ligands, including the endocannabinoids anandamide and 2-arachidonoylglycerol. The goal of this study was to determine whether the recently characterized CB(1) allosteric modulators GAT211 (racemic), GAT228 (R-enantiomer), and GAT229 (S-enantiomer), affected the signs and symptoms of HD. GAT211, GAT228, and GAT229 were evaluated in normal and HD cell models, and in a transgenic mouse model of HD (7-week-old male R6/2 mice, 10 mg/kg/d, 21 d, i.p.). GAT229 was a CB(1) PAM that improved cell viability in HD cells and improved motor coordination, delayed symptom onset, and normalized gene expression in R6/2 HD mice. GAT228 was an allosteric agonist that did not enhance endocannabinoid signaling or change symptom progression in R6/2 mice. GAT211 displayed intermediate effects between its enantiomers. The compounds used here are not drugs, but probe compounds used to determine the potential utility of CB(1) PAMs in HD. Changes in gene expression, and not protein, were quantified in R6/2 HD mice because HD pathogenesis is associated with dysregulation of mRNA levels. The data presented here provide the first proof of principle for the use of CB(1) PAMs to treat the signs and symptoms of HD.
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- 2019
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32. Allosteric Agonism of α7 Nicotinic Acetylcholine Receptors: Receptor Modulation Outside the Orthosteric Site
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Marta Quadri, Sumanta Garai, Nicole A. Horenstein, Roger L. Papke, Ganesh A. Thakur, Clare Stokes, and Alican Gulsevin
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Male ,Models, Molecular ,0301 basic medicine ,Agonist ,alpha7 Nicotinic Acetylcholine Receptor ,medicine.drug_class ,Allosteric regulation ,Molecular Dynamics Simulation ,Partial agonist ,Piperazines ,Cell Line ,Xenopus laevis ,03 medical and health sciences ,0302 clinical medicine ,Allosteric Regulation ,medicine ,Animals ,Humans ,Nicotinic Agonists ,Binding site ,Receptor ,Ion channel ,Acetylcholine receptor ,Pharmacology ,Sulfonamides ,Binding Sites ,Chemistry ,Phenylurea Compounds ,Articles ,Isoxazoles ,Molecular Docking Simulation ,030104 developmental biology ,Nicotinic agonist ,Mutation ,Quinolines ,Biophysics ,Molecular Medicine ,Allosteric Site ,030217 neurology & neurosurgery - Abstract
Nicotinic acetylcholine receptors (nAChRs) are members of the Cys-loop superfamily of ligand-gated ion channels. Typically, channel activation follows the binding of agonists to the orthosteric binding sites of the receptor. α7 nAChRs have a very low probability of channel activation, which can be reversed by the binding of α7 selective positive allosteric modulators (PAMs) to putative sites within the transmembrane domains. Although typical PAMs, like PNU-120596, require coapplication of an orthosteric agonist to produce large channel activations, some, like GAT107 and B-973B [(S)-3-(3,4-difluorophenyl)-N-(1-(6-(4-(pyridin-2-yl)piperazin-1-yl)pyrazin-2-yl)ethyl)propanamide], are characterized as allosteric activating PAMs, which also bind to an allosteric activation (AA) site in the extracellular domain and activate the α7 ion channel by themselves. We had previously characterized N,N-diethyl-N′-phenylpiperazine analogs with various functions. In this work, we docked members of this family to a homology model of the α7 receptor extracellular domain. The compound 1,1-diethyl-4(naphthalene-2-yl)piperazin-1-ium (2NDEP) a weak partial agonist, showed particularly favorable docking and binding energies at the putative AA site of the receptor. We hypothesized that 2NDEP could couple with PAMs through the AA site. This hypothesis was tested with the α7 mutant C190A, which is not activated by orthosteric agonists but is effectively activated by GAT107. The results showed that 2NDEP acts as an allosteric agonist of α7C190A when coapplied with the PAM PNU-120596. Also, the allosteric activity was nearly abolished upon coapplication with the AA site–selective antagonist 2,3,5,6MP-TQS (cis-trans-4-(2,3,5,6-tetramethylphenyl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinoline-8-sulfonamide), consistent with AA site involvement. Overall, our findings show a novel mode of agonism through an allosteric site in the extracellular domain of α7 nAChR.
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- 2019
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33. An Efficient Coloring Algorithm for Time Detraction of Sign Image Segmentation Based on Fuzzy Graph Theory
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Ganesh Kumar Thakur, Bandana Priya, and R K Mishra
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021110 strategic, defence & security studies ,Theoretical computer science ,Mathematics::General Mathematics ,Computer science ,0211 other engineering and technologies ,Graph theory ,Image processing ,02 engineering and technology ,Image segmentation ,Education ,Coloring algorithm ,0202 electrical engineering, electronic engineering, information engineering ,Fuzzy graph ,Graph (abstract data type) ,020201 artificial intelligence & image processing ,Safety, Risk, Reliability and Quality ,Law ,Safety Research ,MathematicsofComputing_DISCRETEMATHEMATICS - Abstract
Graph theory has various applications but sometimes it provides uncertain solutions and hence in order to overcome this, fuzzy graph theory is adopted. Fuzzy graph for any application will be proce...
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- 2019
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34. Potentiation of (α4)2(β2)3, but not (α4)3(β2)2, nicotinic acetylcholine receptors reduces nicotine self-administration and withdrawal symptoms
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Malia Bautista, Asti Jackson, Christie D. Fowler, Lois S. Akinola, Yen-Chu Chen, Yasmin Alkhlaif, Ayman K. Hamouda, Moriah Carper, Ganesh A. Thakur, M. Imad Damaj, Wisam Toma, and Sumanta Garai
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0301 basic medicine ,Nicotinic acetylcholine receptors ,Self Administration ,Pharmacology ,Receptors, Nicotinic ,Nicotinic ,Indole Alkaloids ,Nicotine ,chemistry.chemical_compound ,Mice ,Substance Misuse ,0302 clinical medicine ,Receptors ,Medicine ,Protein Isoforms ,Psychology ,Nicotinic Agonists ,Nicotine withdrawal symptoms ,Behavior, Animal ,Long-term potentiation ,Tobacco Use Disorder ,Pharmacology and Pharmaceutical Sciences ,Hydrocarbons, Brominated ,Substance Withdrawal Syndrome ,Nicotine withdrawal ,Nicotinic agonist ,Desformylflustrabromine ,Positive allosteric modulators ,Hyperalgesia ,Brominated ,medicine.symptom ,Self-administration ,medicine.drug ,Article ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Allosteric Regulation ,Tobacco ,Behavioral and Social Science ,Animals ,Acetylcholine receptor ,Behavior ,Neurology & Neurosurgery ,Tobacco Smoke and Health ,business.industry ,Animal ,Acute thermal nociception ,Nicotine self-administration ,Neurosciences ,Isoxazoles ,medicine.disease ,Hydrocarbons ,Brain Disorders ,Nicotine-induced hypothermia ,030104 developmental biology ,Good Health and Well Being ,chemistry ,Pyrazoles ,business ,Drug Abuse (NIDA only) ,030217 neurology & neurosurgery - Abstract
The low sensitivity (α4)3(β2)2 (LS) and high sensitivity (α4)2(β2)3 (HS) nAChR isoforms may contribute to a variety of brain functions, pathophysiological processes, and pharmacological effects associated with nicotine use. In this study, we examined the contributions of the LS and HS α4β2 nAChR isoforms in nicotine self-administration, withdrawal symptoms, antinociceptive and hypothermic effects. We utilized two nAChR positive allosteric modulators (PAMs): desformylflustrabromine (dFBr), a PAM of both the LS and HS α4β2 nAChRs, and CMPI, a PAM selective for the LS nAChR. We found that dFBr, but not CMPI, decreased intravenous nicotine self-administration in male mice in a dose-dependent manner. Unlike dFBr, which fully reverses somatic and affective symptoms of nicotine withdrawal, CMPI at doses up to 15 mg/kg in male mice only partially reduced nicotine withdrawal-induced somatic signs, anxiety-like behavior and sucrose preference, but had no effects on nicotine withdrawal-induced hyperalgesia. These results indicate that potentiation of HS α4β2 nAChRs is necessary to modulate nicotine's reinforcing properties that underlie nicotine intake and to reverse nicotine withdrawal symptoms that influence nicotine abstinence. In contrast, both dFBr and CMPI enhanced nicotine's hypothermic effect and reduced nicotine's antinociceptive effects in male mice. Therefore, these results indicate a more prevalent role of HS α4β2 nAChR isoforms in mediating various behavioral effects associated with nicotine, whereas the LS α4β2 nAChR isoform has a limited role in mediating body temperature and nociceptive responses. These findings will facilitate the development of more selective, efficacious, and safe nAChR-based therapeutics for nicotine addiction treatment.
- Published
- 2021
35. Discovery of a Biased Allosteric Modulator for Cannabinoid 1 Receptor: Preclinical Anti-Glaucoma Efficacy
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Roger G. Pertwee, Jeffrey R. Deschamps, Patricia H. Reggio, Sumanta Garai, Dow P. Hurst, Tallan Black, Ayat Zagzoog, Peter C Schaffer, Stefan Schulz, Melanie E. M. Kelly, Alex Straiker, Mary E. Abood, Robert B. Laprairie, Ganesh A. Thakur, Anna-Maria Szczesniak, Elke Miess, David R. Janero, and Luciana M Leo
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Agonist ,Male ,Allosteric modulator ,Indoles ,G protein ,medicine.drug_class ,medicine.medical_treatment ,Allosteric regulation ,Molecular Conformation ,CHO Cells ,Pharmacology ,Molecular Dynamics Simulation ,Ligands ,01 natural sciences ,Hippocampus ,03 medical and health sciences ,Structure-Activity Relationship ,Cricetulus ,Receptor, Cannabinoid, CB1 ,Drug Discovery ,medicine ,Potency ,Animals ,Humans ,Receptor ,Intraocular Pressure ,030304 developmental biology ,Cannabinoid Receptor Agonists ,Neurons ,0303 health sciences ,Chemistry ,Glaucoma ,Stereoisomerism ,0104 chemical sciences ,3. Good health ,Mice, Inbred C57BL ,Molecular Docking Simulation ,010404 medicinal & biomolecular chemistry ,HEK293 Cells ,Nitro ,Molecular Medicine ,Cannabinoid ,Allosteric Site - Abstract
We apply the magic methyl effect to improve the potency/efficacy of GAT211, the prototypic 2-phenylindole-based cannabinoid type-1 receptor (CB1R) agonist-positive allosteric modulator (ago-PAM). Introducing a methyl group at the α-position of nitro group generated two diastereomers, the greater potency and efficacy of erythro, (±)-9 vs threo, (±)-10 constitutes the first demonstration of diastereoselective CB1R-allosteric modulator interaction. Of the (±)-9 enantiomers, (-)-(S,R)-13 evidenced improved potency over GAT211 as a CB1R ago-PAM, whereas (+)-(R,S)-14 was a CB1R allosteric agonist biased toward G protein- vs β-arrestin1/2-dependent signaling. (-)-(S,R)-13 and (+)-(R,S)-14 were devoid of undesirable side effects (triad test), and (+)-(R,S)-14 reduced intraocular pressure with an unprecedentedly long duration of action in a murine glaucoma model. (-)-(S,R)-13 docked into both a CB1R extracellular PAM and intracellular allosteric-agonist site(s), whereas (+)-(R,S)-14 preferentially engaged only the latter. Exploiting G-protein biased CB1R-allosteric modulation can offer safer therapeutic candidates for glaucoma and, potentially, other diseases.
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- 2021
36. Stable desensitization of α
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Maria Chiara, Pismataro, Nicole A, Horenstein, Clare, Stokes, Clelia, Dallanoce, Ganesh A, Thakur, and Roger L, Papke
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Binding Sites ,alpha7 Nicotinic Acetylcholine Receptor ,Phenylurea Compounds ,Isoxazoles ,Acetylcholine ,Article ,Drug Partial Agonism ,Molecular Docking Simulation ,Xenopus laevis ,Allosteric Regulation ,Protein Domains ,Serine ,Animals ,Nicotinic Agonists ,Furans ,Azabicyclo Compounds - Abstract
NS6740 is an α(7) nicotinic acetylcholine receptor-selective partial agonist with low efficacy for channel activation, capable of promoting the stable conversion of the receptors to nonconducting (desensitized) states that can be reactivated with the application of positive allosteric modulators (PAMs). In spite of its low efficacy for channel activation, NS6740 is an effective activator of the cholinergic anti-inflammatory pathway. We observed that the concentration-response relationships for channel activation, both when applied alone and when co-applied with the PAM PNU-120596 are inverted-U shaped with inhibitory/desensitizing activities dominant at high concentrations. We evaluated the potential importance of recently identified binding sites for allosteric activators and tested the hypotheses that the stable desensitization produced by NS6740 may be due to binding to these sites. Our experiments were guided by molecular modeling of NS6740 binding to both the allosteric and orthosteric activation sites on the receptor. Our results indicate that with α(7)C190A mutants, which have compromised orthosteric activation sites, NS6740 may work at the allosteric activation sites to promote transient PAM-dependent currents but not the stable desensitization seen with wild-type α(7) receptors. Modeling NS6740 in the orthosteric binding sites identified S36 as an important residue for NS6740 binding and predicted that an S36V mutation would limit NS6740 activity. The efficacy of NS6740 for α(7)S36V receptors was reduced to zero, and applications of the compound to α(7)S36V receptors failed to induce the desensitization observed with wild-type receptors. The results indicate that the unique properties of NS6740 are due primarily to binding at the sites for orthosteric agonists.
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- 2021
37. On the Finite-Time Boundedness and Finite-Time Stability of Caputo-Type Fractional Order Neural Networks with Time Delay and Uncertain Terms
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Bandana Priya, Ganesh Kumar Thakur, M. Syed Ali, Gani Stamov, Ivanka Stamova, and Pawan Kumar Sharma
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Statistics and Probability ,neural networks ,fractional order ,time delay ,uncertain parameters ,finite-time stability ,finite-time boundedness ,Statistical and Nonlinear Physics ,Analysis - Abstract
This study investigates the problem of finite-time boundedness of a class of neural networks of Caputo fractional order with time delay and uncertain terms. New sufficient conditions are established by constructing suitable Lyapunov functionals to ensure that the addressed fractional-order uncertain neural networks are finite-time stable. Criteria for finite-time boundedness of the considered fractional-order uncertain models are also achieved. The obtained results are based on a newly developed property of Caputo fractional derivatives, properties of Mittag–Leffler functions and Laplace transforms. In addition, examples are developed to manifest the usefulness of our theoretical results.
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- 2022
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38. A benzopyran with antiarrhythmic activity is an inhibitor of Kir3.1-containing potassium channels
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Haozhou Tan, Diomedes E. Logothetis, Ganesh A. Thakur, Mengmeng Chang, Said EI-Haou, Obada Abou-Assali, Leigh D. Plant, Keman Xu, Yaser Alhamshari, Meng Cui, Lucas Cantwell, Sami F. Noujaim, James T. Milnes, Meghan Masotti, and Giasemi C. Eptaminitaki
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0301 basic medicine ,Carbachol ,AF, atrial fibrillation ,Protein subunit ,homology modeling ,Action Potentials ,Pharmacology ,Biochemistry ,Kir3, G-protein-gated inwardly rectifying K+ channel subfamily 3 ,IKACh, acetylcholine-activated inwardly rectifying K+ current ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,HK, high potassium ,Atrial Fibrillation ,medicine ,Animals ,Humans ,benzopyran- (BP-) G1, (3R,4S)-7-(hydroxymethyl)-2,2,9-trimethyl-4-(2-phenylethylamino)-3,4-dihydropyrano[2,3-g]quinolin-3-ol ,Channel blocker ,Benzopyrans ,Molecular Biology ,Ion channel ,Proarrhythmia ,HBC, helix bundle crossing ,030102 biochemistry & molecular biology ,Cell Biology ,molecular docking ,medicine.disease ,MD, molecular dynamics ,Potassium channel ,molecular dynamics ,Benzopyran ,Molecular Docking Simulation ,030104 developmental biology ,TEVC, two electrode voltage-clamp ,chemistry ,Mechanism of action ,G Protein-Coupled Inwardly-Rectifying Potassium Channels ,ion channel ,inhibition mechanism ,medicine.symptom ,Anti-Arrhythmia Agents ,Ion Channel Gating ,medicine.drug ,Research Article - Abstract
Atrial fibrillation (AF) is the most commonly diagnosed cardiac arrhythmia and is associated with increased morbidity and mortality. Currently approved AF antiarrhythmic drugs have limited efficacy and/or carry the risk of ventricular proarrhythmia. The cardiac acetylcholine activated inwardly rectifying K+ current (IKACh), composed of Kir3.1/Kir3.4 heterotetrameric and Kir3.4 homotetrameric channel subunits, is one of the best validated atrial-specific ion channels. Previous research pointed to a series of benzopyran derivatives with potential for treatment of arrhythmias, but their mechanism of action was not defined. Here, we characterize one of these compounds termed Benzopyran-G1 (BP-G1) and report that it selectively inhibits the Kir3.1 (GIRK1 or G1) subunit of the KACh channel. Homology modeling, molecular docking, and molecular dynamics simulations predicted that BP-G1 inhibits the IKACh channel by blocking the central cavity pore. We identified the unique F137 residue of Kir3.1 as the critical determinant for the IKACh-selective response to BP-G1. The compound interacts with Kir3.1 residues E141 and D173 through hydrogen bonds that proved critical for its inhibitory activity. BP-G1 effectively blocked the IKACh channel response to carbachol in an in vivo rodent model and displayed good selectivity and pharmacokinetic properties. Thus, BP-G1 is a potent and selective small-molecule inhibitor targeting Kir3.1-containing channels and is a useful tool for investigating the role of Kir3.1 heteromeric channels in vivo. The mechanism reported here could provide the molecular basis for future discovery of novel, selective IKACh channel blockers to treat atrial fibrillation with minimal side effects.
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- 2021
39. WITHDRAWN: Neutrosophic numbers in finding the shortest path using dynamic programming
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Chirag Goyal, S. Ghousia Begum, Ganesh Kumar Thakur, Bandana Priya, and N. Jose Pravin Praveena
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Dynamic programming ,Mathematics::General Mathematics ,Computer science ,Shortest path problem ,Algorithm ,MathematicsofComputing_DISCRETEMATHEMATICS - Abstract
This paper proposed a method to find the shortest path in Neutrosophic environment using a dynamic programming algorithm. Applying Triangular, Trapezoidal and Pentagonal Neutrosophic numbers determine the shortest path. The shortest route is estimated for the acyclic network. Furthermore, we compared the results of Neutrosophic numbers and proved that the results are same.
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- 2021
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40. WITHDRAWN: A new approach to analysis of stock marketing using non-linear differential equations
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Ganesh Kumar Thakur, M.U. Jayanth Sastri, A. Rajkumar, Chirag Goyal, and Bandana Priya
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Computer Science::Computer Science and Game Theory ,Nonlinear system ,Differential equation ,ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION ,Black–Scholes model ,Marketing ,Computer Science::Computers and Society ,Brownian motion ,Purchasing ,Stock (geology) ,Mathematics - Abstract
Purchasing and selling are the very important in stock marketing. In this paper purchasing and selling are converted to a general differential equation and solved the equation by system of simultaneous non liner differential equation method. Finally one example shows the efficiency of this proposed method. Though the renowned Black Scholes model, created on geometric Brownian indication.
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- 2020
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41. WITHDRAWN: Selection of supplier for production strategy for industrial organizations using trapezoidal single valued neuromorphic multi-criteria decision making
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C. Sagaya Nathan Stalin, Bandana Priya, A. Rajkumar, Ganesh Kumar Thakur, and Chirag Goyal
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Production strategy ,Product lifecycle ,Neuromorphic engineering ,Risk analysis (engineering) ,Computer science ,media_common.quotation_subject ,Judgement ,Selection (linguistics) ,Prejudice ,Reputation ,media_common ,Multi criteria decision - Abstract
Effective decision-making should not depend too much on unconscious judgments arising from experience, instincts, or when evidence is bombarded on all directions. Often the inability to either identify or look for important evidence that helps decision-making may be attributed to prejudice, time constraints, funds and other tools. Perhaps the burden involved with corporate decision making is too high to rely about unclear outcomes. The explanations for this are very clear. The brand profile, product lifecycle, financial status and reputation of employers may be influenced by one wrong judgement. The failure to implement economics and statistics principles of some cases requires a different approach to achieve improved performance. In this article, we evaluated supplier selection using for industrial organisations trapezoidal single weighted Neuromorphic numbers.
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- 2020
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42. Peripheral versus central mechanisms of the cannabinoid type 2 receptor agonist AM1710 in a mouse model of neuropathic pain
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Lauren B. Alberti, Jenny L. Wilkerson, Catherine Ledent, Ganesh A. Thakur, Alexandros Makriyannis, Erin D. Milligan, and Audra A. Kerwin
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Agonist ,medicine.medical_specialty ,Cannabinoid receptor ,medicine.drug_class ,medicine.medical_treatment ,050105 experimental psychology ,lcsh:RC321-571 ,Proinflammatory cytokine ,Mice ,03 medical and health sciences ,Behavioral Neuroscience ,0302 clinical medicine ,MCP‐1/CCL‐2 ,Internal medicine ,medicine ,Animals ,0501 psychology and cognitive sciences ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,mouse ,Original Research ,Cannabinoid Receptor Agonists ,Cannabinoids ,business.industry ,05 social sciences ,cannabinoid ,Spinal cord ,medicine.disease ,spectral analysis ,paraffin immunohistochemistry ,medicine.anatomical_structure ,Peripheral neuropathy ,Cytokine ,Endocrinology ,Spinal Cord ,Chromones ,Hyperalgesia ,Neuropathic pain ,Neuralgia ,Cannabinoid ,business ,030217 neurology & neurosurgery - Abstract
The CB2R agonist AM1710, examined in animal models of peripheral neuropathy, is effective in controlling aberrant light touch sensitivity, referred to as mechanical allodynia. However, nonspecific binding of AM1710 to CB1R, either peripherally or centrally, could be partially responsible for the analgesic effects of AM1710. Thus, we sought to determine in mice whether spinal (intrathecal; i.t.) or peripheral AM1710 administration could lead to anti‐allodynia by reducing the protein expression of spinal and dorsal root ganglia (DRG) proinflammatory cytokines and elevating the anti‐inflammatory cytokine interleukin‐10 (IL‐10) in the absence of CB1R. Macrophage cell cultures were examined to characterize AM1710‐mediated suppression of the proinflammatory cytokine tumor necrosis factor‐alpha (TNF‐α). Either i.p. or i.t. AM1710 reversed CCI‐induced mechanical allodynia to sham levels in CB1R (−/−), (+/−), (+/+) mice. CCI‐induced neuropathy decreased IL‐10 immunoreactivity (IR) in the dorsal root ganglia (DRG) and the dorsal horn of the spinal cord, with i.t. AM1710 restoring basal IL‐10 IR. CCI‐induced elevations in proinflammatory cytokine IR were decreased within the spinal cord only after i.t. AM1710 in all mouse genotypes. Meanwhile, within DRG tissue from neuropathic mice, proinflammatory cytokines were decreased following either i.p. or i.t. AM1710. Analysis of cultured supernatants revealed AM1710 decreased TNF‐alpha protein. We conclude that CB1R is dispensable for either peripheral or central anti‐allodynic actions of AM1710 in neuropathic mice. Cannabinoid CB2R agonists produce heightened spinal IL‐10 which may be clinically relevant to successfully treat neuropathic pain., Either i.p. or i.t. AM1710 reversed CCI‐induced mechanical allodynia in CB1R (−/−), (+/−), (+/+) mice similar to sham control threshold levels. The absence of the CB1R following CCI‐induced neuropathy revealed greater significant increases in IL‐10 immunoreactivity (IR) in the dorsal root ganglia (DRG) and the dorsal horn of the spinal cord in (−/−) and (+/−) mice that was further elevated following i.t. and i.p. AM1710. The absence of CB1R may allow for enhanced tissue/axon damage‐associated signaling to the DRG and spinal cord, resulting in endogenous compensatory increases in IL‐10 expression.
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- 2020
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43. Numerical simulation of the movement through a high Reynolds number circular cylinder
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Viraj Dhavalkumar Modi, Chirag Goyal, and Ganesh Kumar Thakur
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Physics ,symbols.namesake ,Computer simulation ,Movement (music) ,symbols ,Reynolds number ,Cylinder ,Mechanics - Published
- 2020
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44. Author response for 'Peripheral versus central mechanisms of the cannabinoid type 2 receptor agonist AM1710 in a mouse model of neuropathic pain'
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Ganesh A. Thakur, Erin D. Milligan, Alexandros Makriyannis, Catherine Ledent, Lauren B. Alberti, Jenny L. Wilkerson, and Audra A. Kerwin
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Agonist ,medicine.drug_class ,business.industry ,medicine.medical_treatment ,Neuropathic pain ,medicine ,Cannabinoid ,Pharmacology ,Receptor ,business ,Peripheral - Published
- 2020
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45. Effects of the cannabinoid receptor 1 positive allosteric modulator GAT211 and acute MK-801 on visual attention and impulsivity in rats assessed using the five-choice serial reaction time task
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Andrew J. Roebuck, Quentin Greba, Timothy J. Onofrychuk, Sumanta Garai, Shuang Cai, Ganesh A. Thakur, Dan L. McElroy, John G. Howland, and Robert B. Laprairie
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Serial reaction time ,Male ,Allosteric modulator ,Indoles ,Impulsivity ,Choice Behavior ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Reaction Time ,Animals ,Attention ,Rats, Long-Evans ,Biological Psychiatry ,Pharmacology ,Cannabinoid Receptor Agonists ,Behavior, Animal ,business.industry ,Glutamate receptor ,Repeated measures design ,Cognition ,medicine.disease ,Endocannabinoid system ,030227 psychiatry ,3. Good health ,Rats ,Schizophrenia ,Impulsive Behavior ,Visual Perception ,medicine.symptom ,Dizocilpine Maleate ,business ,Neuroscience ,Excitatory Amino Acid Antagonists - Abstract
Altered interactions between endocannabinoid and glutamate signaling may be involved in the pathophysiology of schizophrenia and acute psychosis. As cognitive disturbances are involved in schizophrenia, increased understanding of the roles of these neurotransmitter systems in cognition may lead to the development of novel therapeutics for disorder. In the present study, we examined the effects of a recently synthesized cannabinoid receptor 1 (CB1R) positive allosteric modulator GAT211 in a rodent model of acute psychosis induced by systemic treatment with MK-801. To assess cognitive function, we used the Five-Choice Serial Reaction Time (5CSRT) task, conducted in touchscreen-equipped operant conditioning chambers. Our measures of primary interest were accuracy – indicative of visual attentional capacity – and the number of premature responses – indicative of impulsivity. We also measured latencies, omissions, and perseverative responding during all test sessions. Thirteen adult male Long Evans rats were trained on the 5CSRT and were then tested using a repeated measures design with acute MK-801 (0 or 0.15 mg/kg, i.p.) and GAT211 (0, 3, or 10 mg/kg, i.p.) administration. Acute MK-801 severely impaired accuracy, increased omissions, and increased the number of premature responses. MK-801 also significantly increased correct response latencies, without significant effects on incorrect or reward correction latencies. GAT211 had no significant effects when administered alone, or in combination with acute MK-801. These data confirm the dramatic effects of acute MK-801 treatment on behavioral measures of attention and impulsivity. Continued investigation of CB1R positive allosteric modulators as potential treatments for the cognitive symptoms of schizophrenia and related disorders should be pursued in other rodent models.
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- 2020
46. Antipsychotic potential of the type 1 cannabinoid receptor positive allosteric modulator GAT211: preclinical in vitro and in vivo studies
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Dan L, McElroy, Andrew J, Roebuck, Gavin A, Scott, Quentin, Greba, Sumanta, Garai, Eileen M, Denovan-Wright, Ganesh A, Thakur, Robert B, Laprairie, and John G, Howland
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Male ,Indoles ,Behavior, Animal ,Dose-Response Relationship, Drug ,Prepulse Inhibition ,Motor Activity ,Psychoses, Substance-Induced ,Cell Line ,Rats ,Receptor, Cannabinoid, CB1 ,Animals ,Rats, Long-Evans ,Dronabinol ,Dizocilpine Maleate ,Phosphorylation ,Extracellular Signal-Regulated MAP Kinases ,Excitatory Amino Acid Antagonists ,Antipsychotic Agents - Abstract
Antipsychotics help alleviate the positive symptoms associated with schizophrenia; however, their debilitating side effects have spurred the search for better treatment options. Novel compounds can be screened for antipsychotic potential in neuronal cell cultures and following acute N-methyl-D-aspartate (NMDA) receptor blockade with non-competitive antagonists such as MK-801 in rodent behavioral models. Given the known interactions between NMDA receptors and type 1 cannabinoid receptors (CB1R), compounds that modulate CB1Rs may have therapeutic potential for schizophrenia.This study assessed whether the CB1R positive allosteric modulator GAT211, when compared to ∆The effects of GAT211 and THC on cellular signaling were compared in Neuro2a cells, and behavioral effects of GAT211 and THC on altered locomotor activity and prepulse inhibition of the acoustic startle response caused by acute MK-801 treatment were assessed in male, Long Evans rats.GAT211 limited dopamine D2 receptor-mediated extracellular regulated kinase (ERK) phosphorylation in Neuro2a cells, whereas THC did not. As expected, acute MK-801 (0.15 mg/kg) produced a significant increase in locomotor activity and impaired PPI. GAT211 treatment alone (0.3-3.0 mg/kg) dose-dependently reduced locomotor activity and the acoustic startle response. GAT211 (3.0 mg/kg) also prevented hyperlocomotion caused by MK-801 but did not significantly affect PPI impairments.Taken together, these findings support continued preclinical research regarding the usefulness of CB1R positive allosteric modulators as antipsychotics.
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- 2020
47. Focused structure-activity relationship profiling around the 2-phenylindole scaffold of a cannabinoid type-1 receptor agonist-positive allosteric modulator: site-III aromatic-ring congeners with enhanced activity and solubility
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Ganesh A. Thakur, David R. Janero, Pushkar M. Kulkarni, and Peter C. Schaffer
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Agonist ,Allosteric modulator ,Indoles ,medicine.drug_class ,Stereochemistry ,medicine.medical_treatment ,Clinical Biochemistry ,Allosteric regulation ,Pharmaceutical Science ,Biochemistry ,Structure-Activity Relationship ,Allosteric Regulation ,Receptor, Cannabinoid, CB1 ,Drug Discovery ,medicine ,Functional selectivity ,Structure–activity relationship ,Humans ,Solubility ,Molecular Biology ,beta-Arrestins ,Cannabinoid Receptor Agonists ,Chemistry ,Organic Chemistry ,Rational design ,Molecular Docking Simulation ,Kinetics ,Molecular Medicine ,Cannabinoid ,Allosteric Site - Abstract
Specific tuning of cannabinoid 1 receptor (CB1R) activity by small-molecule allosteric modulators is a therapeutic modality with multiple properties inherently advantageous to therapeutic applications. We previously generated a library of unique CB1R positive allosteric modulators (PAMs) derived from GAT211, which has three pharmacophoric sites critical to its ago-PAM activity. To elaborate our CB1R PAM library, we report the rational design and molecular-pharmacology profiling of several 2-phenylindole analogs modified at the "site-III" aromatic ring. The comprehensive structure-activity relationship (SAR) investigation demonstrates that attaching small lipophilic functional groups on the ortho-position of the GAT211 site-III phenyl ring could markedly enhance CB1R ago-PAM activity. Select site-III modifications also improved GAT211's water solubility. The SAR reported both extends the structural diversity of this compound class and demonstrates the utility of GAT211's site-III for improving the parent compound's drug-like properties of potency and/or aqueous solubility.
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- 2020
48. Differing Activity Profiles of the Stereoisomers of 2,3,5,6TMP-TQS, a Putative Silent Allosteric Modulator of
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Roger L, Papke, Sumanta, Garai, Clare, Stokes, Nicole A, Horenstein, Arthur D, Zimmerman, Khalil A, Abboud, and Ganesh A, Thakur
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Models, Molecular ,Sulfonamides ,Binding Sites ,Molecular Structure ,alpha7 Nicotinic Acetylcholine Receptor ,Stereoisomerism ,Articles ,Animals, Genetically Modified ,Molecular Docking Simulation ,Xenopus laevis ,Allosteric Regulation ,Mutation ,Animals ,Humans - Abstract
Many synthetic compounds to which we attribute specific activities are produced as racemic mixtures of stereoisomers, and it may be that all the desired activity comes from a single enantiomer. We have previously shown this to be the case with the α7 nicotinic acetylcholine receptor positive allosteric modulator (PAM) 3a,4,5,9b-Tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS) and the α7 ago-PAM 4BP-TQS. Cis-trans-4-(2,3,5,6-tetramethylphenyl)-3a,4,5,9b-te-trahydro-3H-cyclopenta[c]quinoline-8-sulfonamide (2,3,5,6TMP-TQS), previously published as a “silent allosteric modulator” and an antagonist of α7 allosteric activation, shares the same scaffold with three chiral centers as the aforementioned compounds. We isolated the enantiomers of 2,3,5,6TMP-TQS and determined that the (−) isomer was a significantly better antagonist than the (+) isomer of the allosteric activation of both wild-type α7 and the nonorthosterically activatible C190A α7 mutant by the ago-PAM GAT107 (the active isomer of 4BP-TQS). In contrast, (+)2,3,5,6TMP-TQS proved to be an α7 PAM. (−)2,3,5,6TMP-TQS was shown to antagonize the allosteric activation of α7 by the structurally unrelated ago-PAM B-973B as well as the allosteric activation of the TQS-sensitive α4β2L15′M mutant. In silico docking of 2,3,5,6TMP-TQS in the putative allosteric activation binding site suggested a specific interaction of the (−) enantiomer with α7T106, and allosteric activation of α7T106 mutants was not inhibited by (−)2,3,5,6TMP-TQS, confirming the importance of this interaction and supporting the model of the allosteric binding site. Comparisons and contrasts between 2,3,5,6TMP-TQS isomers and active and inactive enantiomers of other TQS-related compounds identify the orientation of the cyclopentenyl ring to the plane of the core quinoline to be a crucial determinate of PAM activity. SIGNIFICANCE STATEMENT: Many synthetic ligands are in use as racemic preparations. We show that one enantiomer of the TQS analog Cis-trans-4-(2,3,5,6-tetramethylphenyl)-3a,4,5,9b-te-trahydro-3H-cyclopenta[c]quinoline-8-sulfonamide, originally reported to lack activity when used as a racemic preparation, is an α7 nicotinic acetylcholine receptor positive allosteric modulator (PAM). The other enantiomer is not a PAM, but it is an effective allosteric antagonist. In silico studies and structural comparisons identify essential elements of both the allosteric ligands and receptor binding sites important for these allosteric activities.
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- 2020
49. Theory and Applications of Mathematical Science Vol. 3
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Livio Fenga, D. V. Hieu, Efi Fitriana, V. Rhymend Uthariaraj, Hiroshi Inoue, D. T. Hung, N. Q. Hai, Abir Chaouk, Andriy Yurachkivsky, Agus Gunawan, Bandana Priya, Asti Meiza, Maher Jneid, N. K. Sajeevkumar, R. Hemavathy, Sutawanir Darwis, R. Sumitra, and Ganesh Kumar Thakur
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- 2020
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50. GAT107 Attenuates Inflammatory Lung Injury and Mortality in a Mouse Model of Ventilator-Associated Pneumonia by Mitigating Protein-S-Glutathionylation
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Mosi Lin, Alex Gauthier, Ravi Sitapara, Abhijit Kulkarni, Ganesh S. Thakur, Jeanette C. Perron, Charles Ashby, and Lin Mantell
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Physiology (medical) ,Biochemistry - Published
- 2022
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