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In the zebrafish embryo, the onset of blood flow generates fluid shear stress on endocardial cells, which are specialized endothelial cells that line the interior of the heart. High levels of fluid shear stress activate both Notch and Klf2 signaling, which play crucial roles in atrioventricular valvulogenesis. However, it remains unclear why only individual endocardial cells ingress into the cardiac jelly and initiate valvulogenesis. Here, we show that lateral inhibition between endocardial cells, mediated by Notch, singles out Delta-like-4-positive endocardial cells. These cells ingress into the cardiac jelly, where they form an abluminal cell population. Delta-like-4-positive cells ingress in response to Wnt9a, which is produced in parallel through an Erk5-Klf2-Wnt9a signaling cascade also activated by blood flow. Hence, mechanical stimulation activates parallel mechanosensitive signaling pathways that produce binary effects by driving endocardial cells toward either luminal or abluminal fates. Ultimately, these cell fate decisions sculpt cardiac valve leaflets., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Schizophrenia is a common debilitating disease characterized by continuous or relapsing episodes of psychosis. Although the molecular mechanisms underlying this psychiatric illness remain incompletely understood, a growing body of clinical, pharmacological, and genetic evidence suggests that G protein-coupled receptors (GPCRs) play a critical role in disease development, progression, and treatment. This pivotal role is further highlighted by the fact that GPCRs are the most common targets for antipsychotic drugs. The GPCRs activation evokes slow synaptic transmission through several downstream pathways, many of them engaging intracellular Ca 2+ mobilization. Dysfunctions of the neurotransmitter systems involving the action of GPCRs in the frontal and limbic-related regions are likely to underly the complex picture that includes the whole spectrum of positive and negative schizophrenia symptoms. Therefore, the progress in our understanding of GPCRs function in the control of brain cognitive functions is expected to open new avenues for selective drug development. In this paper, we review and synthesize the recent data regarding the contribution of neurotransmitter-GPCRs signaling to schizophrenia symptomology.

The autonomic nervous system (ANS) and renin-angiotensin-aldosterone system (RAAS) are involved in many cardiovascular disorders, including pulmonary hypertension (PH). The current review focuses on the role of the ANS and RAAS activation in PH and updated evidence of potential therapies targeting both systems in this condition, particularly in Groups 1 and 2. State of the art knowledge in preclinical and clinical use of pharmacologic drugs (beta-blockers, beta-three adrenoceptor agonists, or renin-angiotensin-aldosterone signaling drugs) and invasive procedures, such as pulmonary artery denervation, is provided.

Gardenia jasminoides Ellis is a famous fragrant flower in China. Previous pharmacological research mainly focuses on its fruit. In this study, the essential oil of the flower of 'Shanzhizi', which was a major variety for traditional Chinese medicine use, was extracted by hydro distillation and analyzed by GC-MS. Mouse anxiety models included open field, elevated plus maze (EPM), and light and dark box (LDB), which were used to evaluate its anxiolytic effect via inhalation. The involvement of monoamine system was studied by pretreatment with neurotransmitter receptor antagonists WAY100635, flumazenil and sulpiride. The monoamine neurotransmitters contents in the prefrontal cortex (PFC) and hippocampus after aroma inhalation were also analyzed. The results showed that inhalation of G. jasminoides essential oil could significantly elevated the time and entries into open arms in EPM tests and the time explored in the light chamber in LDB tests with no sedative effect. WAY100635 and sulpiride, but not flumazenil, blocked its anxiolytic effect. Inhalation of G. jasminoides essential oil significantly down-regulated the 5-HIAA/5-HT in the PFC and reduced the 5-HIAA content in hippocampus compared to the control treatment. In conclusion, inhalation of gardenia essential oil showed an anxiolytic effect in mice. Monoamine, especially the serotonergic system, was involved in its anxiolytic effect.

Identification and characterization of neuronal cell classes in motor circuits are essential for understanding the neural basis of behavior. It is a challenging task, especially in a non-genetic-model organism, to identify cell-specific expression of functional macromolecules. Here, we performed constellation pharmacology, calcium imaging of dissociated neurons to pharmacologically identify functional receptors expressed by vocal neurons in adult male and female African clawed frogs, Xenopus laevis . Previously we identified a population of vocal neurons called fast trill neurons (FTNs) in the amphibian parabrachial nucleus (PB) that express N -methyl-d-aspartate (NMDA) receptors and GABA and/or glycine receptors. Using constellation pharmacology, we identified four cell classes of putative fast trill neurons (pFTNs, responsive to both NMDA and GABA/glycine applications). We discovered that some pFTNs responded to the application of substance P (SP), acetylcholine (ACh), or both. Electrophysiological recordings obtained from FTNs using an ex vivo preparation verified that SP and/or ACh depolarize FTNs. Bilateral injection of ACh, SP, or their antagonists into PBs showed that ACh receptors are not sufficient but necessary for vocal production, and SP receptors play a role in shaping the morphology of vocalizations. Additionally, we discovered that the PB of adult female X. laevis also contains all the subclasses of neurons at a similar frequency as in males, despite their sexually distinct vocalizations. These results reveal novel neuromodulators that regulate X. laevis vocal production and demonstrate the power of constellation pharmacology in identifying the neuronal subtypes marked by functional expression of cell-specific receptors in non-genetic-model organisms. NEW & NOTEWORTHY Molecular profiles of neurons are critical for understanding the neuronal functions, but their identification is challenging especially in non-genetic-model organisms. Here, we characterized the functional expression of membrane macromolecules in vocal neurons of African clawed frogs, Xenopus laevis , using a technique called constellation pharmacology. We discovered that receptors for acetylcholine and/or substance P are expressed by some classes of vocal neurons, and their activation plays a role in the production of normal vocalizations.

Neurotransmitters are conventionally viewed as nerve-secreted substances that mediate the stimulatory or inhibitory neuronal functions through binding to their respective receptors. In the past decades, many novel discoveries come to light elucidating the regulatory roles of neurotransmitters in the physiological and pathological functions of tissues and organs. Notably, emerging data suggest that cancer cells take advantage of the neurotransmitters-initiated signaling pathway to activate uncontrolled proliferation and dissemination. In addition, neurotransmitters can affect immune cells and endothelial cells in the tumor microenvironment to promote tumor progression. Therefore, a better understanding of the mechanisms underlying neurotransmitter function in tumorigenesis, angiogenesis, and inflammation is expected to enable the development of the next generation of antitumor therapies. Here, we summarize the recent important studies on the different neurotransmitters, their respective receptors, target cells, as well as pro/antitumor activity of specific neurotransmitter/receptor axis in cancers and provide perspectives and insights regarding the rationales and strategies of targeting neurotransmitter system to cancer treatment.

Chromosome conformation capture methods have revealed the dynamics of genome architecture which is spatially organized into topologically associated domains, with gene regulation mediated by enhancer-promoter pairs in chromatin space. New evidence shows that endogenous hormones and several xenobiotics act within circumscribed topological domains of the spatial genome, impacting subsets of the chromatin contacts of enhancer-gene promoter pairs in cis and trans Results from the National Institutes of Health-funded PsychENCODE project and the study of chromatin remodeling complexes have converged to provide a clearer understanding of the organization of the neurogenic epigenome in humans. Neuropsychiatric diseases, including schizophrenia, bipolar spectrum disorder, autism spectrum disorder, attention deficit hyperactivity disorder, and other neuropsychiatric disorders are significantly associated with mutations in neurogenic transcriptional networks. In this review, we have reanalyzed the results from publications of the PsychENCODE Consortium using pharmacoinformatics network analysis to better understand druggable targets that control neurogenic transcriptional networks. We found that valproic acid and other psychotropic drugs directly alter these networks, including chromatin remodeling complexes, transcription factors, and other epigenetic modifiers. We envision a new generation of CNS therapeutics targeted at neurogenic transcriptional control networks, including druggable parts of chromatin remodeling complexes and master transcription factor-controlled pharmacogenomic networks. This may provide a route to the modification of interconnected gene pathways impacted by disease in patients with neuropsychiatric and neurodegenerative disorders. Direct and indirect therapeutic strategies to modify the master regulators of neurogenic transcriptional control networks may ultimately help extend the life span of CNS neurons impacted by disease., (Copyright © 2019 by The American Society for Pharmacology and Experimental Therapeutics.)

Levodopa (LD) is the most effective drug in the treatment of Parkinson's disease (PD). However, although it represents the "gold standard" of PD therapy, LD can cause side effects, including gastrointestinal and cardiovascular symptoms as well as transient elevated liver enzyme levels. Moreover, LD therapy leads to LD-induced dyskinesia (LID), a disabling motor complication that represents a major challenge for the clinical neurologist. Due to the many limitations associated with LD therapeutic use, other dopaminergic and non-dopaminergic drugs are being developed to optimize the treatment response. This review focuses on recent investigations about non-dopaminergic central nervous system (CNS) receptor ligands that have been identified to have therapeutic potential for the treatment of motor and non-motor symptoms of PD. In a different way, such agents may contribute to extending LD response and/or ameliorate LD-induced side effects., Competing Interests: The authors declare no conflict of interest.

We investigated age-related changes in in vivo and in vitro functions and gene expression of the bladder of male and female mice. Mature and aged (12 and 27-30 month old) C57BL/6 mice of both sexes were used. Frequency volume, conscious free-moving cystometry and detrusor contractile and relaxant properties in in vitro organ bath were evaluated. mRNA expression level of muscarinic, purinergic, and β-adrenergic receptors and gene expression changes by cDNA microarray analysis of the bladder were determined. Cystometry demonstrated storage and voiding dysfunctions with ageing in both sexes. Detrusor strips from aged mice showed weaker contractile responses particularly in the cholinergic component and weaker relaxant responses to isoproterenol. These age-related impairments were generally severer in males. mRNA expression of bladder tissue was decreased for M3 muscarinic receptors in aged males and β2-adrenoceptors in aged females. cDNA microarray analysis results, albeit substantial sex difference, indicated "cell-to-cell signaling and interaction" as the most common feature of age-related gene expression. In summary, aged mice demonstrated voiding and storage dysfunctions resembling to detrusor hyperactivity with impaired contractility (DHIC), which were more pronounced in males. Genomic changes associated with aging may contribute to the age-related bladder functional deterioration in mice.

Neuromedin U (NMU) mediates various physiological functions via NMUR1 and NMUR2 receptors. NMUR2 has been considered a promising treatment option for diabetes and obesity. Although NMU-8, a shorter peptide, has potent agonist activity for both receptors, it is metabolically unstable. Therefore, NMU-8 analogs modified with long-chain alkyl moieties via a linker were synthesized. An octadecanoyl analog (17) with amino acid substitutions [αMePhe 19 , Nle 21 , and Arg(Me) 24 ] and a linker [Tra-γGlu-PEG(2)] dramatically increased NMUR2 selectivity, with retention of high agonist activity. Subcutaneous administration of 17 induced anorectic activity in C57BL/6J mice. Owing to its high metabolic stability, 17 would be useful in clarifying the physiological role and therapeutic application of NMU., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Rabies virus induces drastic behaviour modifications in infected hosts. The mechanisms used to achieve these changes in the host are not known. The main finding of this study is that a region in the rabies virus glycoprotein, with homologies to snake toxins, has the ability to alter behaviour in animals through inhibition of nicotinic acetylcholine receptors present in the central nervous system. This finding provides a novel aspect to virus receptor interaction and host manipulation by pathogens in general. The neurotoxin-like region of the rabies virus glycoprotein inhibited acetylcholine responses of α4β2 nicotinic receptors in vitro, as did full length ectodomain of the rabies virus glycoprotein. The same peptides significantly altered a nicotinic receptor induced behaviour in C. elegans and increased locomotor activity levels when injected into the central nervous system of mice. These results provide a mechanistic explanation for the behavioural changes in hosts infected by rabies virus.

The insular cortex (IC) receives projections from prefrontal, entorhinal and cingulate cortex, olfactory bulb and basal nuclei and has reciprocal connections with the amygdala and entorhinal cortex. These connections suggest a possible involvement in memory processes; this has been borne out by data on several behaviors. Social recognition memory (SRM) is essential to form social groups and to establish hierarchies and social and affective ties. Despite its importance, knowledge about the brain structures and the neurotransmitter mechanisms involved in its processing is still scarce. Here we study the participation of NMDA-glutamatergic, D1/D5-dopaminergic, H2-histaminergic, β-adrenergic and 5-HT 1A -serotoninergic receptors of the IC in the consolidation of SRM. Male Wistar rats received intra-IC infusions of substances acting on these receptors immediately after the sample phase of a social discrimination task and 24h later were exposed to a 5-min retention test. The intra-IC infusion of antagonists of D1/D5, β-adrenergic or 5-HT 1A receptors immediately after the sample phase impaired the consolidation of SRM. These effects were blocked by the concomitant intra-IC infusion of agonists of these receptors. Antagonists and agonists of NMDA and H2 receptors had no effect on SRM. The results suggest that the dopaminergic D1/D5, β-adrenergic and serotonergic 5-HT 1A receptors in the IC, but not glutamatergic NMDA and the histaminergic H2 receptors, participate in the consolidation of SRM in the IC., (Copyright © 2017 Elsevier B.V. All rights reserved.)

During acute neuroinflammation, increased levels of cytokines within the brain may contribute to synaptic reorganization that results in long-term changes in network hyperexcitability. Indeed, inflammatory cytokines are implicated in synaptic dysfunction in epilepsy and in an array of degenerative and autoimmune diseases of the central nervous system. Current tools for studying the impact of inflammatory factors on neural networks are either insufficiently fast and sensitive or require complicated and costly experimental rigs. Calcium imaging offers a reasonable surrogate for direct measurement of neuronal network activity, but traditional imaging paradigms are confounded by cellular heterogeneity and cannot readily distinguish between glial and neuronal calcium transients. While the establishment of pure neuron cultures is possible, the removal of glial cells ignores physiologically relevant cell-cell interactions that may be critical for circuit level disruptions induced by inflammatory factors. To overcome these issues, we provide techniques and algorithms for image processing and waveform feature extraction using automated analysis of spontaneous and evoked calcium transients in primary murine cortical neuron cultures transduced with an adeno-associated viral vector driving the GCaMP6f reporter behind a synapsin promoter. Using this system, we provide evidence of network perturbations induced by the inflammatory cytokines TNFα, IL1β, and IFNγ.

Next-generation sequencing (NGS) has contributed to the identification of many monogenic epilepsy syndromes and is favouring earlier and more accurate diagnosis in a subset of paediatric patients with epilepsy. The cumulative information emerging from NGS studies is rapidly changing our comprehension of the relations between early-onset severe epilepsy and the associated neurological impairment, progressively delineating specific entities previously gathered under the umbrella definition of epileptic encephalopathies, thereby influencing treatment choices and limiting the most aggressive drug regimens only to those conditions that are likely to actually benefit from them. Although ion channel genes represent the gene family most frequently causally related to epilepsy, other genes have gradually been associated with complex developmental epilepsy conditions, revealing the pathogenic role of mutations affecting diverse molecular pathways that regulate membrane excitability, synaptic plasticity, presynaptic neurotransmitter release, postsynaptic receptors, transporters, cell metabolism, and many formative steps in early brain development. Some of these discoveries are being followed by proof-of-concept laboratory studies that might open new pathways towards personalized treatment choices. No specific treatment is available for most of the monogenic disorders that can now be diagnosed early using NGS, and the main benefits of knowing the specific cause include etiological diagnosis, better prognostication and genetic counselling; however, for a limited number of disorders, timely treatment based on their known molecular pathology is already possible and sometimes decisive. Discovery of a causative gene defect associated with a non-progressive course may reduce the need for further diagnostic investigations in the search for a progressive disorder at the biochemical and imaging level. NGS has also improved the turnaround time for molecular diagnosis and allowed more timely and straightforward treatment choices for specific conditions as well as avoiding needless investigations and inappropriate or unnecessary treatment choices.

Unilateral dialysis of the broad-spectrum muscarinic receptor antagonist atropine (50 mM) into the ventral respiratory column [(VRC) including the pre-Bötzinger complex region] of awake goats increased pulmonary ventilation (V̇i) and breathing frequency (f), conceivably due to local compensatory increases in serotonin (5-HT) and substance P (SP) measured in effluent mock cerebral spinal fluid (mCSF). In contrast, unilateral dialysis of a triple cocktail of antagonists to muscarinic (atropine; 5 mM), neurokinin-1, and 5-HT receptors does not alter V̇i or f, but increases local SP. Herein, we tested hypotheses that 1 ) local compensatory 5-HT and SP responses to 50 mM atropine dialyzed into the VRC of goats will not differ between anesthetized and awake states; and 2 ) bilateral dialysis of the triple cocktail of antagonists into the VRC of awake goats will not alter V̇i or f, but will increase local excitatory neuromodulators. Through microtubules implanted into the VRC of goats, probes were inserted to dialyze mCSF alone (time control), 50 mM atropine, or the triple cocktail of antagonists. We found 1 ) equivalent increases in local 5-HT and SP with 50 mM atropine dialysis during wakefulness compared with isoflurane anesthesia, but V̇i and f only increased while awake; and 2 ) dialyses of the triple cocktail of antagonists increased V̇i, f, 5-HT, and SP (<0.05) during both day and night studies. We conclude that the mechanisms governing local neuromodulator levels are state independent, and that bilateral excitatory receptor blockade elicits an increase in breathing, presumably due to a local, (over)compensatory neuromodulator response. NEW & NOTEWORTHY The two major findings are as follows: 1) during unilateral dialysis of 50 mM atropine into the ventral respiratory column to block excitatory muscarinic receptor activity, a compensatory increase in other neuromodulators was state independent, but the ventilatory response appears to be state dependent; and 2) the hypothesis that absence of decreased V̇i and f during unilateral dialysis of excitatory receptor antagonists was due to compensation by the contralateral VRC was not supported by findings herein., (Copyright © 2017 the American Physiological Society.)

Combinations of Ca 2+ channel inhibitors have been proposed as an effective means to prevent excess Ca 2+ flux and death of neurons and glia following neurotrauma in vivo. However, it is not yet known if beneficial outcomes such as improved viability have been due to direct effects on intracellular Ca 2+ concentrations. Here, the effects of combinations of Lomerizine (Lom), 2,3-dioxo-7-(1H-imidazol-1-yl)6-nitro-1,2,3,4-tetrahydro-1-quinoxalinyl]acetic acid monohydrate (YM872), 3,5-dimethyl-1-adamantanamine (memantine (Mem)) and/or adenosine 5'-triphosphate periodate oxidized sodium salt (oxATP) to block voltage-gated Ca 2+ channels, Ca 2+ permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, NMDA receptors and purinergic P2X 7 receptors (P2X 7 R) respectively, on Ca 2+ concentration and viability of rat primary mixed cortical (MC) cultures exposed to hydrogen peroxide (H 2 O 2 ) insult, were assessed. The contribution of ryanodine-sensitive intracellular stores to intracellular Ca 2+ concentration was also assessed. Live cell calcium imaging revealed that a 30min H 2 O 2 insult induced a slow increase in intracellular Ca 2+ , in part from intracellular sources, associated with loss of cell viability by 6h. Most combinations of inhibitors that included oxATP significantly decreased Ca 2+ influx and increased cell viability when administered simultaneously with H 2 O 2 . However, reductions in intracellular Ca 2+ concentration were not always linked to improved cell viability. Examination of the density of specific cell subpopulations demonstrated that most combinations of inhibitors that included oxATP preserved NG2+ non-oligodendroglial cells, but preservation of astrocytes and neurons required additional inhibitors. Olig2 + oligodendroglia and ED-1 + activated microglia/macrophages were not preserved by any of the inhibitor combinations. These data indicate that following H 2 O 2 insult, limiting intracellular Ca 2+ entry via P2X 7 R is generally associated with increased cell viability. Protection of NG2+ non-oligodendroglial cells by Ca 2+ channel inhibitor combinations may contribute to observed beneficial outcomes in vivo., (Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.)

The dynamics of amnesia development under conditions of memory reconsolidation disruption by serotonin receptor antagonist methiothepin or NMDA glutamate receptor antagonist MK-801 was studied in snails trained in conventional food aversion. In 2 days after training, injection of methiothepin or MK-801 before reminder induced amnesia development. During repeated training in 3 days after amnesia induction, the skill was formed more rapidly than during the initial training. During repeated training in 10 days after administration of methiothepin and reminder, the dynamics of habit formation was similar to that during initial learning. At the same time, repeated training in 10 days after MK-801 administration and reminder did not result in long-term memory formation. Disruption of reconsolidation of conditioned food aversion memory by antagonists of serotonin or NMDA glutamate receptors led to the development of different types of amnesia that had similar strengthening gradient at the early stages, but differed by the possibility of memory formation during re-training at the late stage.

To understand brain function, it is essential that we discover how cellular signaling specifies normal and pathological brain function. In this regard, chemogenetic technologies represent valuable platforms for manipulating neuronal and non-neuronal signal transduction in a cell-type-specific fashion in freely moving animals. Designer Receptors Exclusively Activated by Designer Drugs (DREADD)-based chemogenetic tools are now commonly used by neuroscientists to identify the circuitry and cellular signals that specify behavior, perceptions, emotions, innate drives, and motor functions in species ranging from flies to nonhuman primates. Here I provide a primer on DREADDs highlighting key technical and conceptual considerations and identify challenges for chemogenetics going forward., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Here we studied whether and through which mechanisms spinal administration of histamine dihydrochloride (histamine) attenuates pain behavior in neuropathic animals. Experiments were performed in rats with spinal nerve ligation-induced neuropathy and a chronic intrathecal catheter for spinal drug delivery. Mechanical hypersensitivity was assessed with monofilaments while radiant heat was used for assessing nociception. Ongoing neuropathic pain and its attenuation by histamine was assessed using conditioned place-preference test. Following spinal administration, histamine at doses 0.1-10µg produced a dose-related mechanical antihypersensitivity effect. With prolonged treatment (twice daily 10µg for five days), the antihypersensitivity effect of spinal histamine was reduced. In place-preference test, neuropathic animals preferred the chamber paired with histamine (10µg). Histamine (10µg) failed to influence heat nociception in neuropathic animals or mechanically induced pain behavior in a group of healthy control rats. Histamine-induced mechanical antihypersensitivity effect was prevented by spinal pretreatment with zolantidine (histamine H2 receptor antagonist), prazosine (α1-adrenoceptor antagonist) and bicuculline (γ-aminobutyric acid subtype A, GABA(A), receptor antagonist), but not by pyrilamine (histamine H1 receptor antagonist), atipamezole (α2-adrenoceptor antagonist), or raclopride (dopamine D2 receptor antagonist). A-960656, a histamine H3 receptor antagonist alone that presumably increased endogenous histamine levels reduced hypersensitivity. Additionally, histamine prevented central (presumably postsynaptically-induced) facilitation of hypersensitivity induced by N-methyl-d-aspartate. The results indicate that spinal histamine at the dose range of 0.1-10µg selectively attenuates mechanical hypersensitivity and ongoing pain in neuropathy. The spinal histamine-induced antihypersensitivity effect involves histamine H2 and GABA(A) receptors and (presumably neuropathy-induced) co-activation of spinal α1-adrenoceptors., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A pressing need in neurobiology is the comprehensive identification and characterization of neuronal subclasses within the mammalian nervous system. To this end, we used constellation pharmacology as a method to interrogate the neuronal and glial subclasses of the mouse cerebellum individually and simultaneously. We then evaluated the data obtained from constellation-pharmacology experiments by cluster analysis to classify cells into neuronal and glial subclasses, based on their functional expression of glutamate, acetylcholine, and GABA receptors, among other ion channels. Conantokin peptides were used to identify N-methyl-d-aspartate (NMDA) receptor subtypes, which revealed that neurons of the young mouse cerebellum expressed NR2A and NR2B NMDA receptor subunits. Additional pharmacological tools disclosed differential expression of α-amino-3-hydroxy-5-methyl-4-isoxazloepropionic, nicotinic acetylcholine, and muscarinic acetylcholine receptors in different neuronal and glial subclasses. Certain cell subclasses correlated with known attributes of granule cells, and we combined constellation pharmacology with genetically labeled neurons to identify and characterize Purkinje cells. This study illustrates the utility of applying constellation pharmacology to classify neuronal and glial subclasses in specific anatomical regions of the brain., (Copyright © 2016 the American Physiological Society.)

Background: Brexpiprazole was recently approved as adjunctive therapy for depression and treatment of schizophrenia in adults. To complement results from a previous study in which its acute effects were characterized, the present study assessed the effect of repeated brexpiprazole administration on monoaminergic systems., Methods: Brexpiprazole (1mg/kg, subcutaneous) or vehicle was administered once daily for 2 and 14 days. Single-unit electrophysiological recordings from noradrenaline neurons in the locus coeruleus, serotonin neurons in the dorsal raphe nucleus, dopaminergic neurons in the ventral tegmental area, and pyramidal neurons in the hippocampus CA3 region were obtained in adult male Sprague-Dawley rats under chloral hydrate anesthesia within 4 hours after final dosing., Results: Brexpiprazole blunted D2 autoreceptor responsiveness, while firing activity of ventral tegmental area dopaminergic neurons remained unaltered. Brexpiprazole increased the firing rate of locus coeruleus noradrenaline neurons and increased noradrenaline tone on α2-adrenergic receptors in the hippocampus. Administration of brexpiprazole for 2 but not 14 days increased the firing rate of serotonin neurons in the dorsal raphe nucleus. In the hippocampus, serotonin1A receptor blockade significantly disinhibited pyramidal neurons after 2- and 14-day brexpiprazole administration. In contrast, no significant disinhibition occurred after 24-hour washout or acute brexpiprazole., Conclusions: Repeated brexpiprazole administration resulted in a marked occupancy of D2 autoreceptors, while discharge activity of ventral tegmental area dopaminergic neurons remained unaltered. Brexpiprazole enhanced serotonergic and noradrenergic tone in the hippocampus, effects common to antidepressant agents. Together, these results provide further insight in the neural mechanisms by which brexpiprazole exerts antidepressant and antipsychotic effects., (© The Author 2015. Published by Oxford University Press on behalf of CINP.)

Previous work in intact awake and sleeping goats has found that unilateral blockade of excitatory inputs in the ventral respiratory column (VRC) elicits changes in the concentrations of multiple neurochemicals, including serotonin (5-HT), substance P, glycine, and GABA, while increasing or having no effect on breathing. These findings are consistent with the concept of interdependence between neuromodulators, whereby attenuation of one modulator elicits compensatory changes in other modulators to maintain breathing. Because there is a large degree of redundancy and multiplicity of excitatory inputs to the VRC, we herein tested the hypothesis that combined unilateral blockade of muscarinic acetylcholine (mACh), neurokinin-1 (NK1, the receptor for substance P), and 5-HT2A receptors would elicit changes in multiple neurochemicals, but would not change breathing. We unilaterally reverse-dialyzed a cocktail of antagonists targeting these receptors into the VRC of intact adult goats. Breathing was continuously monitored while effluent fluid from dialysis was collected for quantification of neurochemicals. We found that neither double blockade of mACh and NK1 receptors, nor triple blockade of mACh, NK1, and 5-HT2A receptors significantly affected breathing (P ≥ 0.05) in goats that were awake or in non-rapid eye movement (NREM) sleep. However, both double and triple blockade increased the effluent concentration of substance P (P < 0.001) and decreased GABA concentrations. These findings support our hypothesis and, together with past data, suggest that both in wakefulness and NREM sleep, multiple neuromodulator systems collaborate to stabilize breathing when a deficit in one or multiple excitatory neuromodulators exists.

Elucidating the roles of neuronal cell types for physiology and behavior is essential for understanding brain functions. Perturbation of neuron electrical activity can be used to probe the causal relationship between neuronal cell types and behavior. New genetically encoded neuron perturbation tools have been developed for remotely controlling neuron function using small molecules that activate engineered receptors that can be targeted to cell types using genetic methods. Here we describe recent progress for approaches using genetically engineered receptors that selectively interact with small molecules. Called "chemogenetics," receptors with diverse cellular functions have been developed that facilitate the selective pharmacological control over a diverse range of cell-signaling processes, including electrical activity, for molecularly defined cell types. These tools have revealed remarkably specific behavioral physiological influences for molecularly defined cell types that are often intermingled with populations having different or even opposite functions.

Synthetic derivatives of phenothiazine have been used for over a century as well-tolerated drugs against a variety of human ailments from psychosis to cancer. This implies a considerable diversity in the mechanisms of action produced by structural changes to the phenothiazine scaffold. For example, chlorpromazine treatment of psychosis is related to its interaction with dopaminergic receptors. On the other hand, antagonistic action of such drugs on cholinergic receptor systems would be counter-productive for treatment of Alzheimer's disease. In a search for phenothiazines that are inhibitors of cholinesterases, especially butyrylcholinesterase, with potential to treat Alzheimer's disease, we wished to ascertain that such molecules could be devoid of neurotransmitter receptor interactions. To that end, a number of our synthetic N-10-carbonyl phenothiazine derivatives, with cholinesterase inhibitory activity, were tested for interaction with a variety of neurotransmitter receptor systems. We demonstrate that phenothiazines can be prepared without significant neurotransmitter receptor interactions while retaining high potency as cholinesterase ligands for treatment of Alzheimer's disease., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The effects of serotonin and glutamate receptor antagonists on conditioned food aversion memory reconsolidation were studied in experiments on edible snails. Injections of NMDA and AMPA glutamate receptor antagonists to trained snails before the reminder were found to induce the development of "irreversible" amnesia: repeated training of these animals was not followed by memory formation. Administration of serotonin receptor antagonist before the reminder led to the development of "reversible" amnesia, repeated training was followed by memory formation. The combined administration of serotonin receptor antagonist with NMDA and AMPA receptor antagonists partially or completely abolished amnesia development. We hypothesized that both memory reconsolidation and amnesia induction require integration of specific patterns converging to neurons and involving certain types of neuro-transmitter receptors.

Past studies have suggested that progesterone-derived ovarian hormones contribute to the discriminative stimulus effects of ethanol, particularly via progesterone metabolites that act at γ-aminobutyric acid type A (GABA(A)) receptors. It is unknown whether loss of ovarian hormones in women, for example, after menopause, may be associated with altered receptor mediation of the effects of ethanol. The current study measured the substitution of allopregnanolone, pregnanolone, pentobarbital, midazolam, dizocilpine, TFMPP, and RU 24969 in female sham and ovariectomized rats trained to discriminate 1.0 g/kg ethanol from water. The groups did not differ in the substitution of GABA(A)-positive modulators (barbiturates, benzodiazepines, neuroactive steroids) or the N-methyl-D-aspartate receptor antagonist dizocilpine. Similarly, blood-ethanol concentration did not differ between the groups, and plasma adrenocorticotropic hormone, progesterone, pregnenolone, and deoxycorticosterone were unchanged 30 min after administration of 1.0 g/kg ethanol or water. However, substitution of neuroactive steroids and RU 24969, a 5-hydroxytryptamine (5-HT)(1A/1B) receptor agonist, was lower than observed in previous studies of male rats, and TFMPP substitution was decreased in ovariectomized rats. Ovarian hormones appear to contribute to 5-HT receptor mediation of the discriminative stimulus effects of ethanol in rats.

Acetylcholine, and to a lesser extent ATP, mediates neurogenic contractions of bladder smooth muscle. Recently, the urothelium and lamina propria have also been shown to have contractile properties, but the neurotransmitters involved in mediating responses to nerve stimulation have not been investigated. Isolated strips of porcine urothelium with lamina propria were electrically field stimulated and contractions recorded. Drugs interfering with neurotransmission were then employed to identify which neurotransmitters mediated responses. Strips of urothelium/lamina propria developed spontaneous contractions with a frequency of 3.5±0.1 cycles min⁻¹ and amplitude of 0.84±0.06 g. Electrical field stimulation at 5, 10, and 20 Hz resulted in frequency-related contractions (1.13±0.36 g, 1.59±0.46 g and 2.20±0.53 g, respectively, n=13), and these were reduced in the presence of tetrodotoxin (1 μm) by 77±20% at 5 Hz, 79±7% at 10 Hz and 74±12% at 20 Hz (all P<0.01), indicating they were predominantly neurogenic in nature. Neither the muscarinic antagonist atropine (10 μm), the adrenergic neurone blocker guanethidine (10 μm) nor desensitization of the purinergic receptors with α,β-methylene ATP (10 μm) affected the contractile amplitude. Similarly, responses were not affected by the nitric oxide synthase inhibitor L-NNA (100 μm) or drugs that interfere with peptide neurotransmission (capsaicin, NK2 antagonist GR159897, protease inhibitors). In conclusion, electrical depolarization of the nerves present in the porcine urothelium/lamina propria results in frequency-dependent contractions, which are predominantly neurogenic in nature. These contractions are resistant to drugs that inhibit the adrenergic, cholinergic and purinergic systems. The neurotransmitter involved in the responses of this tissue is therefore unknown but does not appear to be a peptide., (© 2012 Blackwell Publishing Ltd.)

Foetal cell transplantation in patients with Parkinson's disease can induce motor complications independent of L-DOPA administration, known as graft-induced dyskinesia. In the 6-OHDA lesioned rat model of Parkinson's disease, post-transplantation abnormal movements can develop in response to an amphetamine challenge, a behaviour which is used to model graft-induced dyskinesia. Although L-DOPA-induced dyskinesia has been well characterised pharmacologically, we lack knowledge on the modulation of post-transplantation amphetamine-induced dyskinesia which may shed light on the mechanisms underlying graft-induced dyskinesia. We assessed a series of drugs effective at reducing L-DOPA-induced dyskinesia against post-transplantation amphetamine-induced dyskinesia. Agents include: dopaminergic antagonists (D₁: CP94253; D₂: SCH-22390; D₃: nafadotride), serotonergic agonists (5-HT(1A): 8-OH-DPAT; 5-HT(1B): CP94253), opioid antagonist (μ: naloxone), cannabinoid agonist (CB₁: WIN55, 212-2), adrenergic antagonist (α₁ and α₂: yohimbine) and glutamatergic antagonists (NMDA: amantadine and MK-801; mGluR5: MTEP; AMPA: IEM1460). Abnormal involuntary movements in response to amphetamine were decreased by SCH-22390, raclopride, CP94253 and 8-OH-DPAT, yet were unaltered by naloxone, WIN55, 212-2, yohimbine, amantadine, MTEP and IEM1460. Unusually, MK-801 increased the appearance of amphetamine-induced dyskinesia. The results suggest that dopaminergic, serotoninergic and glutamatergic systems are likely to have a fundamental role in the development of graft-induced dyskinesias, which are mechanistically distinct from L-DOPA-induced behvaviours. Importantly, the expression of D₁ and D₂ receptors was unrelated to the severity of AIMs., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Neuromedin U (NMU) is a structurally highly conserved neuropeptide and has been paired with the G-protein-coupled receptors (GPCRs) NMUR1 and NMUR2, which were formerly classified in the orphan receptor family. Activation of the G protein Gq/11 subunit causes a pertussis toxin (PTX)-insensitive activation of both phospholipase C and mitogen-activated protein kinase (MAP), and activation of the Go subunit causes a PTX-sensitive inhibition of adenyl cyclase. Additionally, NMU selectively inhibits L-type high-voltage-gated Ca2+ channels in mouse hippocampus, as well as low-voltage-activated T-type Ca2+ channels in mouse dorsal root ganglia (DRG). NMU peptide and its receptors are predominantly expressed in the gastrointestinal tract and specific structures within the brain, reflecting its major role in the regulation of energy homeostasis. A novel neuropeptide, neuromedin S (NMS), is structurally related to NMU. They share a C-terminal core structure and both have been implicated in the regulation of food intake, as well as the circadian rhythms. The acute anorectic and weight-reducing effects of NMU and NMS are mediated by NMUR2. This suggests that NMUR2-selective agonists may be useful for the treatment of obesity.

Microglia express three isoforms of the NADPH oxidase, Nox1, Nox2 and Nox4, with the potential to produce superoxide (O(2) ˙(-) ). Microglia also express neurotransmitter receptors, which can modulate microglial responses. In this study, microglial activity of Nox1, Nox2 and Nox4 in primary rat cultured microglia or the rodent BV2 cell line were altered by microglial neurotransmitter receptor modulation. Glutamate, GABA or ATP triggered microglial O(2) ˙(-) production via Nox activation. Nox activation was elicited by agonists of metabotropic mGlu3 receptors and by group III receptors, by GABA(A) but not GABA(B) receptors, and by purinergic P2X(7) or P2Y(2/4) receptors but not P2Y(1) receptors, and inhibited by metabotropic glutamate receptor 5 antagonists. The neurotransmitters also modulated Nox mRNA expression and NADPH activity. The activation of Nox by BzATP or GABA promoted a neuroprotective phenotype whilst the activation of Nox by glutamate promoted a neurotoxic phenotype. Taken together, these data indicate that microglial neurotransmitter receptors can signal via Nox to promote neuroprotection or neurotoxicity. This has implications for the subsequent neurotoxic profile of microglia when neurotransmitter levels may become skewed in neurodegeneration., (© 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.)

Accumbal dopamine plays an important role in physiological responses and diseases such as schizophrenia, Parkinson's disease, and depression. Since the nucleus accumbens contains different neurotransmitters, it is important to know how they interact with dopaminergic function: this is because modifying accumbal dopamine has far-reaching consequences for the treatment of diseases in which accumbal dopamine is involved. This review provides a summary of these interactions, and our current knowledge about them are as follows: A) AMPA receptors are required for dopamine-dependent behavior and vice versa; NMDA receptors modulate the activity at the level of AMPA and/or dopamine D₁ receptors. B) GABA(A), but not GABA(B), receptors inhibit dopamine-dependent behavior. C) Nicotinic receptors are required for dopamine-dependent behavior, whereas muscarinic receptors inhibit dopamine-dependent behavior. D) α-Adrenoceptors inhibit dopamine-dependent behavior in contrast to β-adrenoceptors, which potentiate this behavior. E) μ- and δ₂-opioid receptors elicit behavior that requires an intact dopaminergic function and δ₂-opioid receptors modulate dopamine-dependent behavior. F) Orexin 2 receptors play an important, modifying role in dopamine-dependent behavior. G) Somatostatin receptors potentiate dopamine-dependent behavior. It is suggested that modulation of the above-mentioned non-dopaminergic receptors provide new tools to control physiological functions as well as diseases mediated by accumbal dopamine.

Activation of N-methyl-D-aspartate receptors (NMDARs) has been implicated in various forms of synaptic plasticity depending on the receptor subtypes involved. However, the contribution of NR2A and NR2B subunits in the induction of long-term depression (LTD) of excitatory postsynaptic currents (EPSCs) in layer II/III pyramidal neurons of the young rat visual cortex remains unclear. The present study used whole-cell patch-clamp recordings in vitro to investigate the role of NR2A- and NR2B-containing NMDARs in the induction of LTD in visual cortical slices from 12- to 15-day old rats. We found that LTD was readily induced in layer II/III pyramidal neurons of the rat visual cortex with 10-min 1-Hz stimulation paired with postsynaptic depolarization. D-APV, a selective NMDAR antagonist, blocked the induction of LTD. Moreover, the selective NR2B-containing NMDAR antagonists (Ro 25-6981 and ifenprodil) also prevented the induction of LTD. However, Zn2+, a voltage-independent NR2A-containing NMDAR antagonist, displayed no influence on the induction of LTD. These results suggest that the induction of LTD in layer II/III pyramidal neurons of the young rat visual cortex is NMDAR-dependent and requires NR2B-containing NMDARs, not NR2A-containing NMDARs.

Development of kinase-targeted therapies for central nervous system (CNS) diseases is a great challenge. Glycogen synthase kinase 3 (GSK-3) offers a great potential for severe CNS unmet diseases, being one of the inhibitors on clinical trials for different tauopathies. Following our hypothesis based on the enhanced reactivity of residue Cys199 in the binding site of GSK-3, we examine here the suitability of phenylhalomethylketones as irreversible inhibitors. Our data confirm that the halomethylketone unit is essential for the inhibitory activity. Moreover, addition of the halomethylketone moiety to reversible inhibitors turned them into irreversible inhibitors with IC(50) values in the nanomolar range. Overall, the results point out that these compounds might be useful pharmacological tools to explore physiological and pathological processes related to signaling pathways regulated by GSK-3 opening new avenues for the discovery of novel GSK-3 inhibitors.

The requirement of c-Myb during erythropoiesis spurred an interest in identifying c-Myb target genes that are important for erythroid development. Here, we determined that the neuropeptide neuromedin U (NmU) is a c-Myb target gene. Silencing NmU, c-myb, or NmU's cognate receptor NMUR1 expression in human CD34(+) cells impaired burst-forming unit-erythroid (BFU-E) and colony-forming unit-erythroid (CFU-E) formation compared with control. Exogenous addition of NmU peptide to NmU or c-myb siRNA-treated CD34(+) cells rescued BFU-E and yielded a greater number of CFU-E than observed with control. No rescue of BFU-E and CFU-E growth was observed when NmU peptide was exogenously added to NMUR1 siRNA-treated cells compared with NMUR1 siRNA-treated cells cultured without NmU peptide. In K562 and CD34(+) cells, NmU activated protein kinase C-βII, a factor associated with hematopoietic differentiation-proliferation. CD34(+) cells cultured under erythroid-inducing conditions, with NmU peptide and erythropoietin added at day 6, revealed an increase in endogenous NmU and c-myb gene expression at day 8 and a 16% expansion of early erythroblasts at day 10 compared to cultures without NmU peptide. Combined, these data strongly support that the c-Myb target gene NmU functions as a novel cofactor for erythropoiesis and expands early erythroblasts.

Neuromedin U (NMU) plays very important roles in the central nervous system. However, to date, any role of NMU in hippocampal neurons and the relevant mechanisms still remain unknown. In the present study, we report that NMU selectively inhibits L-type high-voltage-gated Ca(2+) channels (HVGCC) in mouse hippocampal neurons, in which NMU type 1 receptor (NMUR1), but not NMUR2, is endogenously expressed. In wild type mice, NMU (0.1 microM) reversibly inhibited HVGCC barium currents (I(Ba)) by approximately 28%, while in NMUR1(-/-) mice NMU had no significant effects. Intracellular infusion of GDP-beta-S or a selective antibody raised against the G(o)alpha, as well as pretreatment of the neurons with pertussis toxin, blocked the inhibitory effects of NMU, indicating the involvement of G(o)-protein. This NMUR1-mediated effect did not display the characteristics of a direct interaction between G-protein betagamma subunit (G(betagamma)) and L-type HVGCC, but was abolished by dialyzing cells with QEHA peptide or an antibody to the G(beta). The classical and novel protein kinase C (PKC) antagonist calphostin C, as well as phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, abolished NMU responses, whereas the classical PKC antagonist Gö6976 had no such effects. Cells dialyzed with a PKC epsilon isoform (PKCepsilon) specific inhibitor peptide, GAVSLLPT, abolished NMU responses. In contrast, in cells dialyzed with an inactive PKCepsilon control scramble peptide, LSGTLPAV, no significant effects were observed. In summary, these results suggest that NMU inhibits L-type HVGCC via activation of NMUR1 and downstream G(betagamma), PI3K, and a novel PKCepsilon signaling pathway., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

Our previous study has proven that hypothalamic paraventricular nucleus (PVN) plays a role in antinociception. The effects of studied classical neurotransmitter on PVN antinociceptive modulation were investigated in the rat. The results showed: (1) Pain stimulation increased norepinephrine (NE), but not epinephrine, dopamine (DA), 3,4-dihydroxyphenylacetic acid (DA metabolic product), homovanilic acid (DA metabolic product), serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HT metabolic product), acetycholine (Ach), choline (Ach metabolic product), gamma-aminobutyric acid (GABA), and L-glutamate acid concentrations in the PVN perfusion liquid; (2) PVN stimulation with L-glutamate sodium, which excited local neurons only, did not influence the concentrations of the studied classical neurotransmitter and metabolic product in the PVN perfusion liquid; (3) Microinjection of NE, epinephrine, or L-glutamate sodium into the PVN elevated pain threshold, and local administration of GABA decreased pain threshold in a dose-dependent manner, but PVN administration of Ach, DA, or 5-HT did not change pain threshold; (4) Microinjection of phentolamine (alpha-receptor antagonist) or MK801 [NMDA-receptor antagonist] into the PVN reduced pain threshold, and local administration of bicuculline (GABA-receptor antagonist) raised pain threshold, but PVN administration of propranolol (beta-receptor antagonist), atropine (Muscarinic cholinergic receptor antagonist), 6-OH gallamine (Nicotinic cholinergic receptor antagonist), fluperidol (DA-receptor antagonist), or cyproheptadine (5-HT-receptor antagonist) did not alter pain threshold. The data suggested that endogenous NE, not epinephrine, 5-HT, Ach, GABA, and L-glutamate acid played an important role in the PVN antinociceptive modulation.

We propose a mechanism-based modelling approach which brings together the most relevant features of neural dynamics and synaptic transmission for clinically valuable simulations of psychiatric disorders and their pharmaceutical treatment. It is based on a minimal, but physiologically justified concept, which allows to account for a great diversity of neuronal dynamics and synaptic mechanisms. It can simulate ionotropic as well as metabotropic receptors in addition to the effects of eventual co-transmitters and external neuromodulators. The proposed model can mimic the clinically most important aspects of synaptic disturbances, such as impaired transmitter availability or reduced number of postsynaptic receptors, for example due to their internalization as a function of transmitter concentration. It also allows evaluation of the effects of drugs with specific actions such as receptor agonists and antagonists or reuptake inhibitors. It is a major advantage of this physiologically based approach that it can be adjusted to different types of neurons and synapses, and also can be extended to more elaborate physiological situations, e. g. by including additional receptors or ion channels, whenever this is indicated by clinical or experimental data., ((c) Georg Thieme Verlag KG Stuttgart-New York.)

On August 14th, 2009, for the first time, the FDA has approved a psychotropic medication for two indications simultaneously. Saphris (asenapine) is a multitarget atypical antipsychotic medication approved to treat adults with schizophrenia and bipolar I disorder.

Transfer and processing of olfactory information in the antennal lobe of Drosophila relies primarily on neurotransmitters such as acetylcholine and GABA, but novel studies also implicate a neuropeptide: the Drosophila tachykinin (DTK). DTK is expressed in local interneurons that innervate the glomeruli of the antennal lobe with varicose processes. Recently, DTK was shown to mediate presynaptic inhibition of olfactory sensory neurons by physiological and behavioral analysis.(1) That study drew our attention to the issue of alternative targets of DTK in the antennal lobe. Hence, in the present study, we interfered with DTK peptide and DTK receptor (DTKR) expression in local interneurons of the antennal lobe and studied the behavioral outcome of these manipulations. We show that DTKR is expressed not only in olfactory sensory neurons, but likely also in local interneurons. The behavioral consequences of interfering with postsynaptic peptide receptors are different from presynaptic peptide receptor interference. We discuss the possibility that the sum of pre- and postsynaptic interactions may be to modulate the dynamic range in odor sensitivity.

Alcoholism and other alcohol use disorders are major public health problems, and the success rates of non-pharmacological treatment of these disorders such as psychotherapy, cognitive-behavioral therapy, group therapy, or residential treatment programs,remain only modest at best. High rates of recidivism (relapse) in alcoholics attempting to remain abstinent are prevalent worldwide. In recent years abundant evidence has accumulated demonstrating that alcoholism is a complex and multifaceted disease of the brain caused by numerous genetic, neurobiological, developmental, environmental, and socioeconomic factors that are still not yet fully understood.There is thus a great need to improve the success rates of all forms of treatment of alcoholism not only in preventing relapse, but curbing active alcohol consumption and craving. The development of improved pharmacotherapies that could be used as adjuncts to the aforementioned non-pharmacological treatment approaches is one avenue of great interest to the scientific community and the general public. Currently there are only three medications approved by the U.S. Food and Drug Administration (FDA) for use in the treatment of alcohol abuse and alcoholism--disulfiram, naltrexone, and acamprosate. Yet medication compliance issues and the modest efficacy of these compounds leave substantial room for improvement. This special issue is devoted to reviewing the current status of these FDA approved medications in the treatment of alcoholism. In addition, preclinical and clinical evidence suggesting that other classes of medications might also be of potential use are reviewed, including anticonvulsants, GABAB receptor agonists, cholinergic receptor partial agonists, corticotropin-releasing factor and cannabinoid CB1 receptor antagonists, nociceptin receptor ligands, and the novel antipsychotic aripiprazole.

Drug addiction and alcoholism are behavioural disorders characterized by a profound alteration of several brain circuits induced by chronic drug use. Their treatment is yet based on empiricism and today only few pharmacological strategies are fully effective to control both drug use and relapse. The present paper reviews the most updated pharmacotherapies able to contrast both alcoholism and drug addiction including the new patented drugs and the future therapeutic trends.

In the nervous system, spontaneous Ca(2+) transients play important roles in many developmental processes. We previously found that altering the frequency of electrically recorded rhythmic spontaneous bursting episodes in embryonic chick spinal cords differentially perturbed the two main pathfinding decisions made by motoneurons, dorsal-ventral and pool-specific, depending on the sign of the frequency alteration. Here, we characterized the Ca(2+) transients associated with these bursts and showed that at early stages while motoneurons are still migrating and extending axons to the base of the limb bud, they display spontaneous, highly rhythmic, and synchronized Ca(2+) transients. Some precursor cells in the ependymal layer displayed similar transients. T-type Ca(2+) channels and a persistent Na(+) current were essential to initiate spontaneous bursts and associated transients. However, subsequent propagation of activity throughout the cord resulted from network-driven chemical transmission mediated presynaptically by Ca(2+) entry through N-type Ca(2+) channels and postsynaptically by acetylcholine acting on nicotinic receptors. The increased [Ca(2+)](i) during transients depended primarily on L-type and T-type channels with a modest contribution from TRP (transient receptor potential) channels and ryanodine-sensitive internal stores. Significantly, the drugs used previously to produce pathfinding errors altered transient frequency but not duration or amplitude. These observations imply that different transient frequencies may differentially modulate motoneuron pathfinding. However, the duration of the Ca(2+) transients differed significantly between pools, potentially enabling additional distinct pool-specific downstream signaling. Many early events in spinal motor circuit formation are thus potentially sensitive to the rhythmic Ca(2+) transients we have characterized and to any drugs that perturb them.

X-ray structures of molluscan acetylcholine-binding proteins and procaryotic proton-activated ion channels (ELIC and GLIC) enable us to model the ligand binding and activation mechanism of ligand-gated pentameric ion channels. Common versus distinct features can be deduced from the binding of agonists, antagonists and allosteric modulators in subunit interfaces of nicotinic acetylcholine, A-type gamma-aminobutyric acid, glycine and 5-HT(3)-type serotonin receptors. Ligand interactions in subunit interfaces elicit conformational waves from the closure of the agonist-binding cavity through binding loops, beta-strands and transmembrane helices to pore gating.

The effects of red sap from Croton lechleri (SdD), Euphorbiaceae, on vascular and gastric smooth muscles were investigated. SdD, from 10 to 1000 microg/ml, induced concentration-dependent vasoconstriction in rat caudal arteries, which was endothelium-independent. In arterial preparations pre-constricted by phenylephrine (0.1 microM) or KCl (30 mM), SdD also produced concentration-dependent vasoconstriction. To study the mechanisms implicated in this effect we used selective inhibitors such as prazosin (0.1 microM), an antagonist of alpha(1)-adrenoceptors, atropine (0.1 microM), an antagonist of muscarinic receptors, and ritanserin (50 nM), a 5-HT(2A) antagonist; none of these influenced vasoconstriction caused by SdD. Likewise, nifedipine (50 nM), an inhibitor of L-type calcium channels, did not modify the action of SdD. Capsaicin (100 nM), an agonist of vanilloid receptors, also did not affect vasoconstriction by SdD. We also investigated the action of SdD (10-1000 microg/ml) on rat gastric fundus; per se the sap slightly increased contractile tension. When the gastric fundus was pre-treated with SdD (100 microg/ml) the contraction induced by carbachol (1 microM) was increased, whereas that by KCl (60mM) or capsaicin (100 nM) were unchanged. The data shows that SdD increased contractile tension in a concentration-dependent way, both on vascular and gastric smooth muscles. The vasoconstriction is unrelated to alpha(1), M, 5-HT(2A) and vanilloid receptors as well as L-type calcium channels. SdD increased also contraction by carbachol on rat gastric fundus. Thus for the first time, experimental data provides evidence that sap from C. lechleri owns constricting activity on smooth muscles.

Neuromedin U (NMU), through its cognate receptor NMUR2 in the central nervous system, regulates several important physiological functions, including energy balance, stress response, and nociception. By random screening of our corporate compound collection with a ligand binding assay, we discovered (R)-5'-(phenylaminocarbonylamino)spiro[1-azabicyclo[2.2.2]octane-3,2'(3'H)-furo[2,3-b]pyridine] (R-PSOP), a highly potent and selective NMUR2 antagonist. R-PSOP is a nonpeptidic small-molecule with the chemical composition C(20)N(4)O(2)H(22). In competition binding experiments, this compound was found to bind to NMUR2 with high affinity; the K(i) values were determined to be 52 and 32 nM for the human and rat NMUR2, respectively. Moreover, in functional assays measuring phosphoinositide turnover or intracellular calcium mobilization, R-PSOP strongly inhibited the responses stimulated by peptide agonists NMU-25, NMU-23, and NMU-8 in human embryonic kidney 293 cells expressing NMUR2. From Schild analyses, the functional K(b) values for R-PSOP were determined to be 92 and 155 nM at human and rat NMUR2, respectively. Highly selective for NMUR2, R-PSOP exhibited low affinity to the other subtype of NMU receptor, NMUR1, with a K(i) value >10 microM. R-PSOP in vivo attenuated NMU-23-evoked nociceptive responses in a rat spinal reflex preparation. To our knowledge, this is the first antagonist ever reported for NMU receptors. This compound could serve as a valuable tool for further understanding the physiological and pathophysiological roles of NMU system, while providing a chemical starting point that may lead to development of new therapeutics for treatment of eating disorders, obesity, pain, and stress-related disorders.

Background: The World Health Organization (WHO) report has predicted that major depression will become a key cause of illness-induced disability by the year 2020, second only to ischemic heart diseases., Objectives/methods: Although a large number of antidepressant drugs (from monoamine oxidase inhibitors and tricyclic antidepressants to dual reuptake inhibitors) are available for treatment of the disease, approximately 30% of patients failed to respond to this therapy. Therefore, the search for newer or novel drug targets for the treatment of major depression continues. Some of these targets include dopamine, triple reuptake inhibition, L-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway, sigma-1 receptors, neurosteroids, melatonin, glutamate, 5HT6, 5HT7 serotonin receptor antagonists, beta-3 adrenoceptor antagonist, vasopressin V(Ib) receptor antagonists, NK2 tachykinin receptor antagonists, glucocorticoid receptor antagonists and corticotropin-releasing factor-1 receptor antagonists, as well as herbal antidepressant drugs. The present review attempts to discuss the status of some of these novel approaches and the drugs that are under investigation for the treatment of major depression. An attempt is also made to review the status of three indigenous plant-derived drugs, berberine, curcumin and rutin, as novel and safe future herbal antidepressants., Results/conclusion: There is an exciting future in the discovery of novel targets and target-specific agents for the management of major depression.

Mouse embryonic stem cells (mESCs) differentiate into all cardiac phenotypes, and thus represent an important potential source for cardiac regenerative therapies. Here we characterize the molecular composition and functional properties of "funny" (f-) channels in mESC-derived pacemaker cells. Following differentiation, a fraction of mESC-derived myocytes exhibited action potentials characterized by a slow diastolic depolarization and expressed the I(f) current. I(f) plays an important role in the pacemaking mechanism of these cells since ivabradine (3 microM), a specific f-channel inhibitor, inhibited I(f) by about 50% and slowed rate by about 25%. Analysis of I(f) kinetics revealed the presence of two populations of cells, one expressing a fast- and one a slow-activating I(f); the two components are present both at early and late stages of differentiation and had also distinct activation curves. Immunofluorescence analysis revealed that HCN1 and HCN4 are the only isoforms of the pacemaker channel expressed in these cells. Rhythmic cells responded to beta-adrenergic and muscarinic agonists: isoproterenol (1 microM) accelerated and acetylcholine (0.1 microM) slowed spontaneous rate by about 50 and 12%, respectively. The same agonists caused quantitatively different effects on I(f): isoproterenol shifted activation curves by about 5.9 and 2.7 mV and acetylcholine by -4.0 and -2.0 mV in slow and fast I(f)-activating cells, respectively. Accordingly, beta1- and beta2-adrenergic, and M2-muscarinic receptors were detected in mESC-derived myocytes. Our data show that mESC-derived pacemaker cells functionally express proteins which underlie generation and modulation of heart rhythm, and can therefore represent a potential cell substrate for the generation of biological pacemakers.