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Abstract  A relationship between zinc (Zn)-deficiency and mood disorders has been suspected. Here we examined for the first time whether experimentally-induced Zn-deficiency in mice would alter depression- and anxiety-related behaviour assessed in established tests and whether these alterations would be sensitive to antidepressant treatment. Mice receiving a Zn-deficient diet (40% of daily requirement) had similar homecage and open field activity compared to normally fed mice, but displayed enhanced depression-like behaviour in both the forced swim and tail suspension tests which was reversed by chronic desipramine treatment. An anxiogenic effect of Zn-deficiency prevented by chronic desipramine and Hypericum perforatum treatment was observed in the novelty suppressed feeding test, but not in other anxiety tests performed. Zn-deficient mice showed exaggerated stress-evoked immediate-early gene expression in the amygdala which was normalised following DMI treatment. Taken together these data support the link between low Zn levels and depression-like behaviour and suggest experimentally-induced Zn deficiency as a putative model of depression in mice. [ABSTRACT FROM AUTHOR]

Summary.  Down syndrome (DS) is the most common human chromosomal abnormality caused by an extra copy of chromosome 21. The phenotype of DS is thought to result from overexpression of a gene or genes located on the triplicated chromosome or chromosome region. Several reports have shown that the neuropathology of DS comprises developmental abnormalities and Alzheimer-like lesions such as senile plaques. A key component of senile plaques is amyloid β-peptide which is generated from the amyloid precursor protein (APP) by sequential action of β-secretases (BACE1 and BACE2) and γ-secretase. While BACE1 maps to chromosome 11, APP and BACE2 are located on chromosome 21. To challenge the gene dosage effect and gain insight into the expressional relation between β-secretases and APP in DS brain, we evaluated protein expression levels of BACE1, BACE2 and APP in fetal and adult DS brain compared to controls. In fetal brain, protein expression levels of BACE2 and APP were comparable between DS and controls. BACE1 was increased, but did not reach statistical significance. In adult brain, BACE1 and BACE2 were comparable between DS and controls, but APP was significantly increased. We conclude that APP overexpression seems to be absent during the development of DS brain up to 18–19 weeks of gestational age. However, its overexpression in adult DS brain could lead to disturbance of normal function of APP contributing to neurodegeneration. Comparable expression of BACE1 and BACE2 speaks against the hypothesis that increased β-secretase results in (or even underlies) increased production of amyloidogenic Aβ fragments. Furthermore, current data indicate that the DS phenotype cannot be fully explained by simple gene dosage effect. [ABSTRACT FROM AUTHOR]

Summary.  Handling and detoxification of metals by enzymes is a major issue that is not in the focus of current biomedical research concepts. The finding of the presence of arsenic (+3 Oxidation State) methyltransferase (AS3MT) in neuroblastoma cells NE-115 as a high abundance protein made us investigate primary structure of AS3MT reflecting an example of metal-handling in eucaryotes. Proteins extracted from NE-115 cells were run on 2-DE followed by two different mass spectrometrical methods. High sequence coverage was obtained by multiple protease digestion and a sequence conflict was solved at arginine 335. These findings are important when future studies on this enzyme are designed at the protein level and in particular, when antibodies against this protein will be generated. [ABSTRACT FROM AUTHOR]

Summary.   Anterior gradient protein 2 homolog is a metastasis-inducing protein in a rat model of rat breast cancer and prognostic for outcome in hormonally treated breast cancer patients. Carrying out protein profiling in several mammalian cells and tissues, we detected this protein (synonym: secreted cement gland protein XAG-2 homolog) that was originally described in toad skin, in human bronchial epithelia. Tissues obtained from biopsies were homogenised and extracted proteins were run on two-dimensional gel electrophoresis. Following in-gel digestion with proteases trypsin, AspN, LysC and chymotrypsin, mass spectrometrical analysis was carried out by MALDI-TOF/TOF. The use of MS following multi-enzyme digestion of the protein resulted into 100% sequence coverage. MS/MS analysis enabled sequencing of 87% of the protein structure. This percentage does not include the signal peptide that was not observed in our protein due to processing. No posttranslational modifications were detectable and no sequence conflicts were observed. Complete analysis, unambiguous identification and characterisation of this biologically important protein could be shown, which is relevant for the definition of a marker protein that has been described so far by immunochemical methods only. Complete analysis is of importance as it forms the basis for all future work on this protein and, moreover, may serve as an analytical tool for further studies. [ABSTRACT FROM AUTHOR]

Summary.  A series of cognitive enhancers (CEs) have been reported to increase spatial memory in rodents, information on behavioral effects, however, is limited. The aim of the study was therefore to examine the behavioral effects of three CEs in two well-documented inbred mouse strains. C57BL/6J and DBA/2 mice were administered intraperitonial. D-cycloserine (DCS; NMDA receptor agonist), 1-(4-Amino-5-chloro-2-methoxyphenyl)-3-[1-butyl-4-piperidinyl]-1-propanone hydrochloride (RS67333; 5HT4-receptor agonist), and (R)-4-{[2-(1-methyl-2-pyrrolidinyl)ethyl]thio}phenol hydrochloride (SIB-1553A; β-4-nicotinic receptor agonist) and tested in the open field (OF), elevated plus maze (EPM), neurological observational battery and rota-rod. Cognitive performance was tested in the Morris water maze. All compounds modified behavioral performance in the OF, DCS showed an anxiolytic effect in the EPM, and differences in the observational battery were observed i.e. vestibular drop was decreased by SIB-1553A and RS67333 treatment in C57BL/6J and increased with DCS treatment in DBA/2 mice. In the rota rod SIB-1553A improved motor performance. DCS effects on learning and memory was comparable to controls whereas the other compounds impaired performance in the Morris water maze. In conclusion, behavioral testing of CEs in the mouse revealed significant changes that may have to be taken into account for evaluation of CEs, interpretation of cognitive studies and warrant further neurotoxicological studies. Moreover, strain-dependent differences were observed that in turn may confound results obtained from behavioral and cognitive testing. [ABSTRACT FROM AUTHOR]

Summary.  No systematic approach to detect expression of differentiation-related elements was published so far. The undifferentiated N1E-115 neuroblastoma cell line was switched into a neuronal phenotype by DMSO treatment and used for proteomic experiments. We used two-dimensional gel electrophoresis followed by unambiguous mass spectrometrical identification of proteins to generate a map of cytoskeleton proteins (CPs), i.e., to search for differentiation-related structures. Alpha-actin, actin-like protein 6A, gamma-tubulin complex component 2, tubulin alpha 3/alpha 7, CLIP associating protein 2, B4 integrin interactor homolog were detectable in the undifferentiated cell line exclusively and neuron-specific CPs drebrin and presynaptic density protein 95, actin-related protein 2/3, alpha and beta-centractin, PDZ-domain actin binding protein, actinin alpha 1, profilin II, ezrin, coactosin-like protein, transgelin 2, myosin light polypeptide 6, tubulin alpha 2, 6 and 7, beta tubulin (94% similar with tubulin beta-2), tubulin beta 3, tubulin tyrosine ligase-like protein 1, lamin B1 and keratin 20 were observed in the differentiated cell line only. We herein identified differentiation-related expressional patterns thus providing new evidence for the role of CPs in the process of neuronal differentiation. [ABSTRACT FROM AUTHOR]

Abstract  Galectins are a family of animal lectins with specificity for β-galactosides and are involved in a host of cellular activities, ranging from development to cancer. The molecules are expressed by neural and non-neural cells intracellularly as well as extracellularly. Using two-dimensional gel electrophoresis coupled to tandem mass spectrometry, the present work aimed to identify and characterize galectins in primary rat cerebellar astrocytes. The protein-chemical method identified nine spots representing two members of the galectin family, namely galectin-1 and galectin-3. These findings suggest that high abundant expression of galectin in astrocytes is limited to the two abundant galectin family members. As these family members are linked to human astrocytic tumors, their reliable detection in astrocytes by proteomic techniques would enable us to further understand their role in neural development, injury, and regeneration in general and astrocytoma in particular. [ABSTRACT FROM AUTHOR]

Mesial temporal lobe epilepsy (MTLE), the most common form of epilepsy, is characterised by cytoarchitectural abnormalities including neuronal cell loss and reactive gliosis in hippocampus. Determination of aberrant cytoskeleton protein expression by proteomics techniques may help to understand pathomechanism that is still elusive. We searched for differential expression of hippocampal proteins by an analytical method based on two-dimensional gel electrophoresis (2-DE) coupled with mass spectrometry unambiguously identifying 77 proteins analysed in eight control and eight MTLE hippocampi. Proteins were quantified and we observed 18 proteins that were altered in MTLE. Cytoskeleton proteins tubulin α-1 chain, β-tubulin, profilin II, neuronal tropomodulin were significantly reduced and one actin spot was missing, whereas ezrin and vinculin were significantly increased in MTLE. Proteins of several classes as e.g. antioxidant proteins (peroxiredoxins 3 and 6), chaperons (T-complex protein 1-α, stress-induced-phosphoprotein 1), signaling protein MAP kinase kinase 1, synaptosomal proteins (synaptotagmin I, α-synuclein), NAD-dependent deacetylase sirtuin-2 and 26S protease regulatory subunit 7 protein, neuronal-specific septin 3 were altered in MTLE. Taken together, the findings may represent or lead to cytoskeletal impairment; aberrant antioxidant proteins, chaperons, MAP kinase kinase 1 and NAD-dependent deacetylase sirtuin-2 may have been involved in pathogenetic mechanisms and altered synaptosomal protein expression possibly reflects synaptic impairment in MTLE. [ABSTRACT FROM AUTHOR]

Involvement of individual antioxidant proteins (AOXP) and antioxidants in the differentiation process has been already reported. A systematic search strategy for detecting differentially regulated AOXP in neuronal differentiation, however, has not been published so far. The aim of this study was to provide an analytical tool identifying AOXP and to generate a differentiation-related AOXP expressional pattern. [ABSTRACT FROM AUTHOR]

Summary. The central nervous system is an important potential target for certain environmental prototoxins, but relatively little is known regarding brain-specific expression of biotransformation enzyme systems. On the other hand, developments in the field of molecular biology and advances in high-throughput screening methods continue to increase the number and amounts of available proteins. We used thus a robust and reliable technique, two-dimensional gel electrophoresis coupled to matrix assisted laser desorption/ionisation mass spectroscopy followed by tandem mass spectrometry and identified for the first time soluble epoxide hydrolase and added other biotransformation enzymes in the hippocampal region of mouse brain. Soluble epoxide hydrolase has an Mr of 61.5?kDa, pI of 5.9, twenty-six matching peptides and sequence coverage of 56% and was unambiguously identified by MS/MS. Since localised biotransformation events in regions of the central nervous system may account for pathologies and/or toxicities initiated by exposure to certain endogenous and/or environmental chemicals, identification of these enzymes would present an opportunity for developing novel therapeutic targets or would have critical toxicologic significance. [ABSTRACT FROM AUTHOR]

Summary. Down Syndrome (DS, trisomy 21) is the most common genetic cause of mental retardation. The completed sequencing of genes encoded on chromosome 21 provides excellent basic information, however the molecular mechanisms leading to the phenotype of DS remain to be elucidated. Although overexpression of chromosome 21 encoded genes has been documented information at the protein expression level is mandatory as it is the proteins that carry out function. We therefore decided to evaluated expression level of seven proteins whose genes are encoded on chromosome 21: DSCR4, DSCR5, DSCR6; KIR4.2, GIRK2, KCNE1 and KCNE2 in fetal cortex brain of DS and controls at the early second trimester of pregnancy by Western blotting. ß-actin and neuron specific enolase (NSE) were used to normalise cell loss and neuronal loss. DSCR5 (PIG-P), a component of glycosylphosphatidylinositol- N-acetylglucosaminyltransferase (GPI-GnT), was overexpressed about twofold, even when levels were normalised with NSE. DSCR6 was overexpressed in addition but when normalised versus NSE, levels were comparable to controls. DSCR4 was not detectable in fetal brain. Potassium channels KIR4.2 and GIRK2 were comparable between DS and controls, whereas KCNE1 and KCNE2 were not detectable. Quantification of these proteins encoded on chromosome 21 revealed that not all gene products of the DS critical region are overexpressed in DS brain early in life, indicating that the DS phenotype cannot be simply explained by the gene dosage effect hypothesis. Overexpression of PIG-P (DSCR5) may lead to or represent impaired glycosylphosphatidylinositol- N-acetylglucosaminyltransferase mediated posttranslational modifications and subsequent anchoring of proteins to the plasma membrane. [ABSTRACT FROM AUTHOR]

Summary. The human genome maybe limited to about 30?000 genes whereas the human proteome may be represented by a rough estimate of one million proteins. A legion of proteins have been described and information about these structures are readily available in data banks. There remains, however, a large series of unknown or hypothetical proteins (HPs). Many of them have been predicted from nucleic acid sequences only and are therefore named predicted or HPs. Carrying out ?protein hunting? by generating large maps of human cell lines, we aimed to find and identify HPs and provide an analytical tool thereof. Cell lysates from human bronchial epithelial, fibroblast, amnion, lymphocyte, mesothelial and kidney cell lines were prepared and proteins run on two-dimensional gel-electrophoresis (2DE) with in-gel digestion and mass spectrometrical analysis using the MALDI-TOF principle. 16 HPs were found in these cell lines and some show cell-specific expressional patterns. HPs belong to several protein classes including structural, signaling, transcriptional/translational, chaperone-related and others. We furthermore provide analytical data i.e. pIs that were often different from predicted values in data banks. A list of HPs has been shown to really exist in several human cell lines thus contributing to knowledge on protein machineries and cascades. Observed and predicted pI values are given representing an analytical tool along with unambiguous identification of protein spots by mass spectrometry independent of antibody availability and specificity thus complementing established methods. [ABSTRACT FROM AUTHOR]

Summary. Down syndrome (DS) is the most frequent genetic disorder with mental retardation and caused by trisomy 21. Although the molecular mechanisms of the various phenotypes of DS could be due to overexpression of gene(s) on chromosome 21, several groups have challenged this gene dosage effect hypothesis. The near completion of the sequencing of human chromosome 21 provides unprecedented opportunities to understand the molecular pathology of DS, however, functional information on gene products is limited so far. We therefore evaluated the levels of six proteins whose genes are encoded on chromosome 21 (trefoil factor 1, trefoil factor 2, trefoil factor 3, coxsackie virus and adenovirus receptor, carbonyl reductase 1 and interferon-α receptor) in fetal cerebral cortex from DS and controls at the early second trimester using Western blot analysis. None of the investigated proteins showed overexpression in DS compared to controls suggesting that these proteins are not involved in abnormal development of fetal DS brain and that DS phenotype can not be simply explained by the gene dosage effect hypothesis. We are systematically quantifying all proteins whose genes are encoded on chromosome 21 and these studies may provide a better understanding of genotype-phenotype correlation in DS. [ABSTRACT FROM AUTHOR]

Empirical evidence suggests that heat exposure reduces food intake. However, the neurocircuit architecture and the signalling mechanisms that form an associative interface between sensory and metabolic modalities remain unknown, despite primary thermoceptive neurons in the pontine parabrachial nucleus becoming well characterized 1 . Tanycytes are a specialized cell type along the wall of the third ventricle 2 that bidirectionally transport hormones and signalling molecules between the brain's parenchyma and ventricular system 3-8 . Here we show that tanycytes are activated upon acute thermal challenge and are necessary to reduce food intake afterwards. Virus-mediated gene manipulation and circuit mapping showed that thermosensing glutamatergic neurons of the parabrachial nucleus innervate tanycytes either directly or through second-order hypothalamic neurons. Heat-dependent Fos expression in tanycytes suggested their ability to produce signalling molecules, including vascular endothelial growth factor A (VEGFA). Instead of discharging VEGFA into the cerebrospinal fluid for a systemic effect, VEGFA was released along the parenchymal processes of tanycytes in the arcuate nucleus. VEGFA then increased the spike threshold of Flt1-expressing dopamine and agouti-related peptide (Agrp)-containing neurons, thus priming net anorexigenic output. Indeed, both acute heat and the chemogenetic activation of glutamatergic parabrachial neurons at thermoneutrality reduced food intake for hours, in a manner that is sensitive to both Vegfa loss-of-function and blockage of vesicle-associated membrane protein 2 (VAMP2)-dependent exocytosis from tanycytes. Overall, we define a multimodal neurocircuit in which tanycytes link parabrachial sensory relay to the long-term enforcement of a metabolic code., (© 2024. The Author(s).)

Large-scale syntheses of small molecules and kilo laboratories are crucial steps in drug development, especially in advanced stages. ( S )-5-((Benzhydrylsulfinyl)methyl)thiazole, ( S )-CE-123, a potent, selective, and novel atypical DAT inhibitor, has undergone iterative testing as part of the preclinical evaluation step. This required the process transfer, scale-up, and synthesis of a 1 kg preclinical batch. The Kagan protocol for asymmetric sulfide to sulfoxide oxidation was successfully applied within a four-step synthetic process for the successful upscaling of ( S )-CE-123. During the scale-up of the last step, several changes were made to the original synthetic procedure, as with every increase in batch size, new problems had to be overcome. These include, among others, the workup optimization of the last step, the simplification of chromatographic purification, elution modification to improve the purity of the product and saving of workup time. Two washing steps were added to the original procedure to enhance both the yield and the enantiomeric excess value of the final product. The modifications introduced allowed access to a 1 kg ( S )-CE-123 batch with a purity >99% and an enantiomeric excess value of 95%., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Introduction: Deterioration of cognitive functions is commonly associated with aging, although there is wide variation in the onset and manifestation. Albeit heterogeneity in age-related cognitive decline has been studied at the cellular and molecular level, there is poor evidence for electrophysiological correlates. The aim of the current study was to address the electrophysiological basis of heterogeneity of cognitive functions in cognitively Inferior and Superior old (19-20 months) rats in the ventral tegmental area (VTA) and the hippocampus, having Young (12 weeks) rats as a control. The midbrain VTA operates as a hub amidst affective and cognitive facets, processing sensory inputs related to motivated behaviours and hippocampal memory. Increasing evidence shows direct dopaminergic and non-dopaminergic input from the VTA to the hippocampus., Methods: Aged Superior and Inferior male rats were selected from a cohort of 88 animals based on their performance in a spatial learning and memory task. Using in vivo single-cell recording in the VTA, we examined the electrical activity of different neuronal populations (putative dopaminergic, glutamatergic and GABAergic neurons). In the same animals, basal synaptic transmission and synaptic plasticity were examined in hippocampal slices., Results: Electrophysiological recordings from the VTA and hippocampus showed alterations associated with aging per se , together with differences specifically linked to the cognitive status of aged animals. In particular, the bursting activity of dopamine neurons was lower, while the firing frequency of glutamatergic neurons was higher in VTA of Inferior old rats. The response to high-frequency stimulation in hippocampal slices also discriminated between Superior and Inferior aged animals., Discussion: This study provides new insight into electrophysiological information underlying compromised cerebral ageing. Further understanding of brain senescence, possibly related to neurocognitive decline, will help develop new strategies towards the preservation of a high quality of life., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Sagheddu, Stojanovic, Kouhnavardi, Savchenko, Hussein, Pistis, Monje, Plasenzotti, Aufy, Studenik, Lubec and Lubec.)

Children with fetal alcohol spectrum disorders (FASDs) demonstrate deficits in social functioning that contribute to early withdrawal from school and delinquency, as well as the development of anxiety and depression. Dopamine is involved in reward, motivation, and social behavior. Thus, we evaluated whether neonatal ethanol exposure (in an animal model of FASDs) has an impact on social recognition memory using the three-chamber social novelty discrimination test during early and middle adolescence in male and female rats, and whether the modafinil analog, the novel atypical dopamine reuptake inhibitor CE-123, can modify this effect. Our study shows that male and female rats neonatally exposed to ethanol exhibited sex- and age-dependent deficits in social novelty discrimination in early (male) and middle (female) adolescence. These deficits were specific to the social domain and not simply due to more general deficits in learning and memory because these animals did not exhibit changes in short-term recognition memory in the novel object recognition task. Furthermore, early-adolescent male rats that were neonatally exposed to ethanol did not show changes in the anxiety index but demonstrated an increase in locomotor activity. Chronic treatment with CE-123, however, prevented the appearance of these social deficits. In the hippocampus of adolescent rats, CE-123 increased BDNF and decreased its signal transduction TrkB receptor expression level in ethanol-exposed animals during development, suggesting an increase in neuroplasticity. Thus, selective dopamine reuptake inhibitors, such as CE-123, represent interesting drug candidates for the treatment of deficits in social behavior in adolescent individuals with FASDs.

Leishmaniasis is a complex group of infectious and parasitic diseases that afflict many thousands of individuals across five continents. Leishmaniasis treatment remains a challenge because it relies on drugsknown for their high toxicity and limited efficacy, making itimperative to identify new molecules that offer greater effectiveness and safety. This study sought to explore the impact of seven synthetic guanidine derivatives (LQOF-G1, LQOF-G2, LQOF-G6, LQOF-G7, LQOF-G32, LQOF-G35 and LQOF-G36) onthe parasite Leishmania (Viannia) braziliensis and in vitro macrophage infection by this parasite, as well as cytotoxic approaches in vitro models of mammalian host cells and tissues. The synthesized compounds showed purity ≥ 99.65% and effectively inhibited parasite growth. LQOF-G1 proved the most potent, yielding the best half-maximal inhibitory concentration (IC 50 ) values against promastigotes (4.62 μmol/L), axenic amastigotes (4.27 μmol/L), and intracellular amastigotes (3.65 μmol/L). Notably, the antileishmanial activity of LQOF-G1, LQOF-G2, and LQOF-G6 was related to immunomodulatory effects, evidenced by alterations in TNF-α, IL-12, IL-10, nitric oxide (NO), and reactive oxygen species (ROS) levels in the supernatant of culture macrophages infected with L. (V.) braziliensis and coincubated with these compounds. LQOF-G2 and LQOF-G36 compounds exhibited vasodilator and spasmolytic effects at higher concentrations (≥100 μmol/L). Generally, LQOF-G1, LQOF-G2, and LQOF-G32 compounds were found to be nontoxic to assessed organs and cells. No toxic effects were observed in human cell lines, such as HEK-293, CaCo-2 and A549, at concentrations ≥ 500 μmol/L. Collectively, data have shown unequivocal evidence of the effectiveness of these compounds against L. (V.) braziliensis parasite, one of the causative agents of Tegumentary Leishmaniasis and Mucocutaneous Leishmaniasis in America.

S -CE-123, a novel dopamine transporter inhibitor, has emerged as a potential candidate for cognitive enhancement. The objective of this study was to compare the tissue distribution profiles, with a specific focus on central nervous system distribution and metabolism, of S -CE-123 and R -modafinil. To address this objective, a precise liquid chromatography-high resolution mass spectrometry method was developed and partially validated. Neuropharmacokinetic parameters were assessed using the Combinatory Mapping Approach. Our findings reveal distinct differences between the two compounds. Notably, S -CE-123 demonstrates a significantly superior extent of transport across the blood-brain barrier (BBB), with an unbound brain-to-plasma concentration ratio (K p,uu,brain ) of 0.5, compared to R -modafinil's K p,uu,brain of 0.1. A similar pattern was observed for the transport across the blood-spinal cord barrier. Concerning the drug transport across cellular membranes, we observed that S -CE-123 primarily localizes in the brain interstitial space, whereas R -modafinil distributes more evenly across both sides of the plasma membrane of the brain's parenchymal cells (K p,uu,cell ). Furthermore, our study highlights the substantial differences in hepatic metabolic stability, with S -CE-123 having a 9.3-fold faster metabolism compared to R -modafinil. In summary, the combination of improved BBB transport and higher affinity of S -CE-123 to dopamine transporters in comparison to R -modafinil makes S -CE-123 a promising candidate for further testing for the treatment of cognitive decline.

Background: Dopamine plays a key role in several physiological functions such as motor control, learning and memory, and motivation and reward. The atypical dopamine transporter inhibitor S,S stereoisomer of 5-(((S)-((S)-(3-bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiazole (CE-158) has been recently reported to promote behavioral flexibility and restore learning and memory in aged rats., Methods: Adult male rats were i.p. administered for 1 or 10 days with CE-158 at the dose of 1 or 10 mg/kg and tested for extracellular dopamine in the medial prefrontal cortex by means of intracerebral microdialysis and single unit cell recording in the same brain area. Moreover, the effects of acute and chronic CE-158 on exploratory behavior, locomotor activity, prepulse inhibition, working memory, and behavioral flexibility were also investigated., Results: CE-158 dose-dependently potentiated dopamine neurotransmission in the medial prefrontal cortex as assessed by intracerebral microdialysis. Moreover, repeated exposure to CE-158 at 1 mg/kg was sufficient to increase the number of active pyramidal neurons and their firing frequency in the same brain area. In addition, CE-158 at the dose of 10 mg/kg stimulates exploratory behavior to the same extent after acute or chronic treatment. Noteworthy, the chronic treatment at both doses did not induce any behavioral alterations suggestive of abuse potential (e.g., motor behavioral sensitization) or pro-psychotic-like effects such as disruption of sensorimotor gating or impairments in working memory and behavioral flexibility as measured by prepulse inhibition and Y maze., Conclusions: Altogether, these findings confirm CE-158 as a promising pro-cognitive agent and contribute to assessing its preclinical safety profile in a chronic administration regimen for further translational testing., (© The Author(s) 2023. Published by Oxford University Press on behalf of CINP.)

The high structural similarity, especially in transmembrane regions, of dopamine, norepinephrine, and serotonin transporters, as well as the lack of all crystal structures of human isoforms, make the specific targeting of individual transporters rather challenging. Ligand design itself is also rather limited, as many chemists, fully aware of the synthetic and analytical challenges, tend to modify lead compounds in a way that reduces the number of chiral centers and hence limits the potential chemical space of synthetic ligands. We have previously shown that increasing molecular complexity by introducing additional chiral centers ultimately leads to more selective and potent dopamine reuptake inhibitors. Herein, we significantly extend our structure-activity relationship of dopamine transporter-selective ligands and further demonstrate how stereoisomers of defined absolute configuration may fine-tune and direct the activity towards distinct targets. From the pool of active compounds, using the examples of stereoisomers 7h and 8h , we further showcase how in vitro activity significantly differs in in vivo drug efficacy experiments, calling for proper validation of individual stereoisomers in animal studies. Furthermore, by generating a large library of compounds with defined absolute configurations, we lay the groundwork for computational chemists to further optimize and rationally design specific monoamine transporter reuptake inhibitors.

Leishmaniasis refers to a collection of diseases caused by protozoa from the Leishmania genus. These diseases, along with other parasitic afflictions, pose a significant public health issue, particularly given the escalating number of at-risk patients. This group includes immunocompromised individuals and those residing in impoverished conditions. The treatment of leishmaniasis is crucial, particularly in light of the mortality rate associated with nontreatment, which stands at 20-30,000 deaths per year globally. However, the therapeutic options currently available are limited, often ineffective, and potentially toxic. Consequently, the pursuit of new therapeutic alternatives is warranted. This study aims to design, synthesize, and evaluate the leishmanicidal activity of antimicrobial peptides functionalized with guanidine compounds and identify those with enhanced potency and selectivity against the parasite. Accordingly, three bioconjugates were obtained by using the solid-phase peptide synthesis protocol. Each proved to be more potent against intracellular amastigotes than their respective peptide or guanidine compounds alone and demonstrated higher selectivity to the parasites than to the host cells. Thus, the conjugation strategy employed with these compounds effectively contributes to the development of new molecules with leishmanicidal activity., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Introduction: Aging is in general associated with a decline in cognitive functions. Looking more closely, there is a huge heterogeneity in the extent of cognitive (dys-)abilities in the aged population. It ranges from the population of resistant, resilient, cognitively unimpaired individuals to patients with severe forms of dementias. Besides the known genetic, environmental and life style factors that shape the cognitive (dys-)abilities in aging, the underlying molecular mechanisms and signals related to cognitive heterogeneity are completely unknown. One putative mechanism underlying cognitive heterogeneity might be neuroinflammation, exerted through microglia, the brain's innate immune cells, as neuroinflammation is central to brain aging and neurodegenerative diseases. Recently, leukotrienes (LTs), i.e., small lipid mediators of inflammation produced by microglia along aging and neurodegeneration, got in the focus of geroscience as they might determine cognitive dysfunctions in aging., Methods: Here, we analyzed the brain's expression of key components of the LT synthesis pathway, i.e., the expression of 5-lipoxygenase (5-Lox), the key enzyme in LT production, and 5-lipoxygenase-activating protein (FLAP) in young and aged rats. More specifically, we used a cohort of rats, which, although grown up and housed under identical conditions, developed into aged cognitively unimpaired and aged cognitively impaired traits., Results: Expression of 5-Lox was increased within the brain of aged rats with the highest levels detected in cognitively impaired animals. The number of microglia cells was higher in the aged compared to the young brains with, again, the highest numbers of 5-Lox expressing microglia in the aged cognitively impaired rats. Remarkably, lower cognitive scores in the aged rats associated with higher numbers of 5-Lox positive microglia in the animals. Similar data were obtained for FLAP, at least in the cortex. Our data indicate elevated levels of the LT system in the brain of cognitively impaired animals., Discussion: We conclude that 5-Lox expressing microglia potentially contribute to the age-related cognitive decline in the brain, while low levels of the LT system might indicate and foster higher cognitive functions and eventually cognitive reserve and resilience in aging., Competing Interests: LA was a consultant of IntelGenx Corp., who is repurposing Montelukast as a therapeutic in AD. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Mrowetz, Kotob, Forster, Aydin, Unger, Lubec, Hussein, Malikovic, Feyissa, Korz, Höger, Lubec and Aigner.)

Cortisol is a potent human steroid hormone that plays key roles in the central nervous system, influencing processes such as brain neuronal synaptic plasticity and regulating the expression of emotional and behavioral responses. The relevance of cortisol stands out in the disease, as its dysregulation is associated with debilitating conditions such as Alzheimer's Disease, chronic stress, anxiety and depression. Among other brain regions, cortisol importantly influences the function of the hippocampus, a structure central for memory and emotional information processing. The mechanisms fine-tuning the different synaptic responses of the hippocampus to steroid hormone signaling remain, however, poorly understood. Using ex vivo electrophysiology and wild type (WT) and miR-132/miR-212 microRNAs knockout (miRNA-132/212 -/- ) mice, we examined the effects of corticosterone (the rodent's equivalent to cortisol in humans) on the synaptic properties of the dorsal and ventral hippocampus. In WT mice, corticosterone predominantly inhibited metaplasticity in the dorsal WT hippocampi, whereas it significantly dysregulated both synaptic transmission and metaplasticity at dorsal and ventral regions of miR-132/212 -/- hippocampi. Western blotting further revealed significantly augmented levels of endogenous CREB and a significant CREB reduction in response to corticosterone only in miR-132/212 -/- hippocampi. Sirt1 levels were also endogenously enhanced in the miR-132/212 -/- hippocampi but unaltered by corticosterone, whereas the levels of phospo-MSK1 were only reduced by corticosterone in WT, not in miR-132/212 -/- hippocampi. In behavioral studies using the elevated plus maze, miRNA-132/212 -/- mice further showed reduced anxiety-like behavior. These observations propose miRNA-132/212 as potential region-selective regulators of the effects of steroid hormones on hippocampal functions, thus likely fine-tuning hippocampus-dependent memory and emotional processing.

The worldwide increase in cognitive decline, both in aging and with psychiatric disorders, warrants a search for pharmacological treatment. Although dopaminergic treatment approaches represent a major step forward, current dopamine transporter (DAT) inhibitors are not sufficiently specific as they also target other transporters and receptors, thus showing unwanted side effects. Herein, we describe an enantiomerically pure, highly specific DAT inhibitor, S-CE-123, synthetized in our laboratory. Following binding studies to DAT, NET and SERT, GPCR and kinome screening, pharmacokinetics and a basic neurotoxic screen, S-CE-123 was tested for its potential to enhance and/or rescue cognitive functions in young and in aged rats in the non-invasive reward-motivated paradigm of a hole-board test for spatial learning. In addition, an open field study with young rats was carried out. We demonstrated that S-CE-123 is a low-affinity but highly selective dopamine reuptake inhibitor with good bioavailability. S-CE-123 did not induce hyperlocomotion or anxiogenic or stereotypic behaviour in young rats. Our compound improved the performance of aged but not young rats in a reward-motivated task. The well-described impairment of the dopaminergic system in aging may underlie the age-specific effect. We propose S-CE-123 as a possible candidate for developing a tentative therapeutic strategy for age-related cognitive decline and cognitive dysfunction in psychiatric disorders.

Psychostimulants interacting with the dopamine transporter (DAT) can be used illicitly or for the treatment of specific neuropsychiatric disorders. However, they can also produce severe and persistent adverse events. Often, their pharmacological properties in vitro do not fully correlate to their pharmacological profile in vivo. Here, we investigated the pharmacological effects of enantiomers of pyrovalerone, α-pyrrolidinovalerophenone, and 3,4-methylenedioxypyrovalerone as compared to the traditional psychostimulants cocaine and methylphenidate, using a variety of in vitro, computational, and in vivo approaches. We found that in vitro drug-binding kinetics at DAT correlate with the time-course of in vivo psychostimulant action in mice. In particular, a slow dissociation (i.e., slow k off ) of S -enantiomers of pyrovalerone analogs from DAT predicts their more persistent in vivo effects when compared to cocaine and methylphenidate. Overall, our findings highlight the critical importance of drug-binding kinetics at DAT for determining the in vivo profile of effects produced by psychostimulant drugs.

Extracellular dopamine (DA) levels are constrained by the presynaptic DA transporter (DAT), a major psychostimulant target. Despite its necessity for DA neurotransmission, DAT regulation in situ is poorly understood, and it is unknown whether regulated DAT trafficking impacts dopaminergic signaling and/or behaviors. Leveraging chemogenetics and conditional gene silencing, we found that activating presynaptic Gq-coupled receptors, either hM3Dq or mGlu5, drove rapid biphasic DAT membrane trafficking in ex vivo striatal slices, with region-specific differences between ventral and dorsal striata. DAT insertion required D2 DA autoreceptors and intact retromer, whereas DAT retrieval required PKC activation and Rit2. Ex vivo voltammetric studies revealed that DAT trafficking impacts DA clearance. Furthermore, dopaminergic mGlu5 silencing elevated DAT surface expression and abolished motor learning, which was rescued by inhibiting DAT with a subthreshold CE-158 dose. We discovered that presynaptic DAT trafficking is complex, multimodal, and region specific, and for the first time, we identified cell autonomous mechanisms that govern presynaptic DAT tone. Importantly, the findings are consistent with a role for regulated DAT trafficking in DA clearance and motor function., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Leishmaniasis is a highly prevalent, yet neglected disease caused by protozoan parasites of the genus Leishmania . In the search for newer, safer, and more effective antileishmanial compounds, we herein present a study of the mode of action in addition to a detailed structural and biological characterization of LQOF-G6 [ N -benzoyl- N '-benzyl- N ″-(4-tertbutylphenyl)guanidine]. X-ray crystallography and extensive NMR experiments revealed that LQOF-G6 nearly exclusively adopts the Z conformation stabilized by an intramolecular hydrogen bond. The investigated guanidine showed selective inhibitory activity on Leishmania major cysteine protease Lm CPB2.8ΔCTE (CPB) with ~73% inhibition and an IC 50-CPB of 6.0 µM. This compound did not show any activity against the mammalian homologues cathepsin L and B. LQOF-G6 has been found to be nontoxic toward both organs and several cell lines, and no signs of hepatotoxicity or nephrotoxicity were observed from the analysis of biochemical clinical plasma markers in the treated mice. Docking simulations and experimental NMR measurements showed a clear contribution of the conformational parameters to the strength of the binding in the active site of the enzyme, and thus fit the differences in the inhibition values of LQOF-G6 compared to the other guanidines. Furthermore, the resulting data render LQOF-G6 suitable for further development as an antileishmanial drug.

Maternal separation (MS) is a key contributor to neurodevelopmental disorders, including learning disabilities. To test the hypothesis that dopamine signaling is a major factor in this, an atypical new dopamine transporter (DAT) inhibitor, CE-123, was assessed for its potential to counteract the MS-induced spatial learning and memory deficit in male and female rats. Hence, neonatal rats (postnatal day (PND)1 to 21) were exposed to MS (180 min/day). Next, the acquisition of spatial learning and memory (Barnes maze task) and the expression of dopamine D1 receptor, dopamine transporter (DAT), and the neuronal GTPase, RIT2, which binds DAT in the vehicle-treated rats were evaluated in the prefrontal cortex and hippocampus in the adolescent animals. The results show that MS impairs the acquisition of spatial learning and memory in rats, with a more severe effect in females. Moreover, the MS induced upregulation of DAT and dopamine D1 receptors expression in the prefrontal cortex and hippocampus in adolescent rats. Regarding RIT2, the expression was decreased in the hippocampus for both the males and females, however, in the prefrontal cortex, reduction was found only in the females, suggesting that there are region-specific differences in DAT endocytic trafficking. CE-123 ameliorated the behavioral deficits associated with MS. Furthermore, it decreased the MS-induced upregulation of D1 receptor expression level in the hippocampus. These effects were more noted in females. Overall, CE-123, an atypical DAT inhibitor, is able to restore cognitive impairment and dopamine signaling in adolescent rats exposed to MS-with more evident effect in females than males.

Loss of cognitive function is a typical consequence of aging in humans and rodents. The extent of decline in spatial memory performance of rats, assessed by a hole-board test, reaches from unimpaired and comparable to young individuals to severely memory impaired. Recently, proteomics identified peroxiredoxin 6, an enzyme important for detoxification of oxidized phospholipids, as one of several synaptosomal proteins discriminating between aged impaired and aged unimpaired rats. In this study, we investigated several components of the epilipidome (modifications of phospholipids) of the prefrontal cortex of young, aged memory impaired (AI) and aged unimpaired (AU) rats. We observed an age-related increase in phospholipid hydroperoxides and products of phospholipid peroxidation, including reactive aldehydophospholipids. This increase went in hand with cortical lipofuscin autofluorescence. The memory impairment, however, was paralleled by additional specific changes in the aged rat brain epilipidome. There was a profound increase in phosphocholine hydroxides, and a significant decrease in phosphocholine-esterified azelaic acid. As phospholipid-esterified fatty acid hydroxides, and especially those deriving from arachidonic acid are both markers and effectors of inflammation, the findings suggest that in addition to age-related reactive oxygen species (ROS) accumulation, age-related impairment of spatial memory performance has an additional and distinct (neuro-) inflammatory component., (© 2022. The Author(s).)

Dopamine (DA), the most abundant human brain catecholaminergic neurotransmitter, modulates key behavioral and neurological processes in young and senescent brains, including motricity, sleep, attention, emotion, learning and memory, and social and reward-seeking behaviors. The DA transporter (DAT) regulates transsynaptic DA levels, influencing all these processes. Compounds targeting DAT (e.g., cocaine and amphetamines) were historically used to shape mood and cognition, but these substances typically lead to severe negative side effects (tolerance, abuse, addiction, and dependence). DA/DAT signaling dysfunctions are associated with neuropsychiatric and progressive brain disorders, including Parkinson's and Alzheimer diseases, drug addiction and dementia, resulting in devastating personal and familial concerns and high socioeconomic costs worldwide. The development of low-side-effect, new/selective medicaments with reduced abuse-liability and which ameliorate DA/DAT-related dysfunctions is therefore crucial in the fields of medicine and healthcare. Using the rat as experimental animal model, the present work describes the synthesis and pharmacological profile of ( S )-MK-26, a new modafinil analogue with markedly improved potency and selectivity for DAT over parent drug. Ex vivo electrophysiology revealed significantly augmented hippocampal long-term synaptic potentiation upon acute, intraperitoneally delivered ( S )-MK-26 treatment, whereas in vivo experiments in the hole-board test showed only lesser effects on reference memory performance in aged rats. However, in effort-related FR5/chow and PROG/chow feeding choice experiments, ( S )-MK-26 treatment reversed the depression-like behavior induced by the dopamine-depleting drug tetrabenazine (TBZ) and increased the selection of high-effort alternatives. Moreover, in in vivo microdialysis experiments, ( S )-MK-26 significantly increased extracellular DA levels in the prefrontal cortex and in nucleus accumbens core and shell. These studies highlight ( S )-MK-26 as a potent enhancer of transsynaptic DA and promoter of synaptic plasticity, with predominant beneficial effects on effort-related behaviors, thus proposing therapeutic potentials for ( S )-MK-26 in the treatment of low-effort exertion and motivational dysfunctions characteristic of depression and aging-related disorders.

Alterations in cognitive functions, social behaviors and stress reactions are commonly diagnosed in chronic mental illnesses (CMI). Animal models expressing mutant genes associated to CMI represent either rare mutations or those contributing only minimally to genetic risk. Non-genetic causes of CMI can be modeled by disturbing downstream signaling pathways, for example by inducing protein misassembly or aggregation. The Disrupted-in-Schizophrenia 1 (DISC1) gene was identified to be disrupted and thereby haploinsufficient in a large pedigree where it was associated with CMI. In a subset of CMI patients, the DISC1 protein misassembles to an insoluble protein. This has been modeled in a rat (tgDISC1 rat) where the full-length, non mutant human transgene was overexpressed and cognitive impairments were observed. Here, we investigated the scope of effects of DISC1 protein misassembly by investigating spatial memory, social behavior and stress resilience. In water maze tasks, the tgDISC1 rats showed intact spatial learning and memory, but were deficient in flexible adaptation to spatial reversal learning compared to littermate controls. They also displayed less social interaction. Additionally, there was a trend towards increased corticosterone levels after restraint stress in the tgDISC1 rats. Our findings suggest that DISC1 protein misassembly leads to disturbances of cognitive flexibility and social behaviors, and might also be involved in stress sensitization. Since the observed behavioral features resemble symptoms of CMI, the tgDISC1 rat may be a valuable model for the investigation of cognitive, social and - possibly - also stress-related symptoms of major mental illnesses., (Copyright © 2022 IBRO. Published by Elsevier Ltd. All rights reserved.)

Previous studies have shown that atypical dopamine-transporter-inhibitors such as modafinil and its analogues modify behavioral and cognitive functions in rodents. Here, we tested potential promnestic effects of the novel, more dopamine-transporter selective modafinil analogue CE-158 in the social discrimination memory task in male mice. Systemic administration of CE-158 1 h before the social learning event prevented the impairment of social-recognition memory following retroactive interference 3 h after the learning session of a juvenile conspecific. This effect was dose-dependent, as mice treated with 10 mg/kg, but not with 1 mg/kg CE-158, were able to discriminate between the novel and familiar conspecific despite the presentation of an interference stimulus, both 3 h and 6 h post learning. However, when 10 mg/kg of the drug was administered after learning, CE-158 failed to prevent social memory from interference. Paralleling these behavioral effects, the systemic administration of 10 mg/kg CE-158 caused a rapid and sustained elevation of extracellular dopamine in the nucleus accumbens, a brain area where dopaminergic signaling plays a key role in learning and memory function, of freely moving mice, while 1 mg/kg was not sufficient for altering dopamine levels. Taken together, our findings suggest promnestic effects of the novel dopamine-transporter-inhibitor CE-158 in a social recognition memory test that may be in part mediated via increased dopamine-neurotransmission in the nucleus accumbens. Thus, selective-dopamine-transporter-inhibitors such as CE-158 may represent interesting drug candidates for the treatment of memory complaints observed in humans with cognitive impairments and dementia.

Dopamine (DA) is critically involved in different functions of the central nervous system (CNS) including control of voluntary movement, affect, reward, sleep, and cognition. One of the key components of DA neurotransmission is DA reuptake by the DA transporter (DAT), ensuring rapid clearance of DA from the synaptic cleft. Thus, lack of DAT leads to persistent high extracellular DA levels. While there is strong evidence for a role of striatal dopaminergic activity in learning and memory processes, little is known about the contribution of DAT deficiency to conditional learning impairments and underlying molecular processes. DAT-knockout (DAT-KO) rats were tested in a set of behavioral experiments evaluating conditional associative learning, which requires unaltered striatal function. In parallel, a large-scale proteomic analysis of the striatum was performed to identify molecular factors probably underlying behavioral patterns. DAT-KO rats were incapable to acquire a new operant skill in Pavlovian/instrumental autoshaping, although the conditional stimulus-unconditional stimulus (CS-US) association seems to be unaffected. These findings suggest that DAT directly or indirectly contributes to the reduction of transference of incentive salience from the reward to the CS. We propose that specific impairment of conditional learning might be caused by molecular adaptations to the hyperdopaminergic state, presumably by dopamine receptor 1 (DRD1) hypofunction, as proposed by proteomic analysis. Whether DRD1 downregulation can cause cognitive deficits in the hyperdopaminergic state is the subject of discussion, and further studies are needed to answer this question. This study may be useful for the interpretation of previous and the design of future studies in the dopamine field., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Savchenko, Müller, Lubec, Leo, Korz, Afjehi-Sadat, Malikovic, Sialana, Lubec and Sukhanov.)

Nicotine addiction develops predominantly during human adolescence through smoking. Self-administration experiments in rodents verify this biological preponderance to adolescence, suggesting evolutionary-conserved and age-defined mechanisms which influence the susceptibility to nicotine addiction. The hippocampus, a brain region linked to drug-related memory storage, undergoes major morpho-functional restructuring during adolescence and is strongly affected by nicotine stimulation. However, the signaling mechanisms shaping the effects of nicotine in young vs. adult brains remain unclear. MicroRNAs (miRNAs) emerged recently as modulators of brain neuroplasticity, learning and memory, and addiction. Nevertheless, the age-dependent interplay between miRNAs regulation and hippocampal nicotinergic signaling remains poorly explored. We here combined biophysical and pharmacological methods to examine the impact of miRNA-132/212 gene-deletion (miRNA-132/212 -/- ) and nicotine stimulation on synaptic functions in adolescent and mature adult mice at two hippocampal synaptic circuits: the medial perforant pathway (MPP) to dentate yrus (DG) synapses (MPP-DG) and CA3 Schaffer collaterals to CA1 synapses (CA3-CA1). Basal synaptic transmission and short-term (paired-pulse-induced) synaptic plasticity was unaltered in adolescent and adult miRNA-132/212 -/- mice hippocampi, compared with wild-type controls. However, nicotine stimulation promoted CA3-CA1 synaptic potentiation in mature adult (not adolescent) wild-type and suppressed MPP-DG synaptic potentiation in miRNA-132/212 -/- mice. Altered levels of CREB, Phospho-CREB, and acetylcholinesterase (AChE) expression were further detected in adult miRNA-132/212 -/- mice hippocampi. These observations propose miRNAs as age-sensitive bimodal regulators of hippocampal nicotinergic signaling and, given the relevance of the hippocampus for drug-related memory storage, encourage further research on the influence of miRNAs 132 and 212 in nicotine addiction in the young and the adult brain.

Dopamine is an important neurotransmitter that regulates numerous essential functions, including cognition and voluntary movement. As such, it serves as an important scaffold for synthesis of novel analogues as part of drug development effort to obtain drugs for treatment of neurodegenerative diseases, such as Parkinson's disease. To that end, similarity search of the ZINC database based on two known dopamine-1 receptor (D1R) agonists, dihydrexidine (DHX) and SKF 38393, respectively, was used to predict novel chemical entities with potential binding to D1R. Three compounds that showed the highest similarity index were selected for synthesis and bioactivity profiling. All main synthesis products as well as the isolated intermediates, were properly characterized. The physico-chemical analyses were performed using HRESIMS, GC/MS, LC/MS with UV-Vis detection, and FTIR, 1 H NMR and 13 C NMR spectroscopy. Binding to D1 and D2 receptors and inhibition of dopamine reuptake via dopamine transporter were measured for the synthesized analogues of DHX and SKF 38393., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

The lack of novel cognitive enhancer drugs in the clinic highlights the prediction problems of animal assays. The objective of the current study was to test a putative cognitive enhancer in a rodent cognitive test system with improved translational validity and clinical predictivity. Cognitive profiling was complemented with post mortem proteomic analysis. Twenty-seven male Lister Hooded rats (26 months old) having learned several cognitive tasks were subchronically treated with S-CE-123 (CE-123) in a randomized blind experiment. Rats were sacrificed after the last behavioural procedure and plasma and brains were collected. A label-free quantification approach was used to characterize proteomic changes in the synaptosomal fraction of the prefrontal cortex. CE-123 markedly enhanced motivation which resulted in superior performance in a new-to-learn operant discrimination task and in a cooperation assay of social cognition, and mildly increased impulsivity. The compound did not affect attention, spatial and motor learning. Proteomic quantification revealed 182 protein groups significantly different between treatment groups containing several proteins associated with aging and neurodegeneration. Bioinformatic analysis showed the most relevant clusters delineating synaptic vesicle recycling, synapse organisation and antioxidant activity. The cognitive profile of CE-123 mapped by the test system resembles that of modafinil in the clinic showing the translational validity of the test system. The findings of modulated synaptic systems are paralleling behavioral results and are in line with previous evidence for the role of altered synaptosomal protein groups in mechanisms of cognitive function., (© 2021. The Author(s).)

Perinatal alcohol exposure can lead to fetal alcohol spectrum disorders (FASD), usually first diagnosed in childhood, that are characterized by hyperactivity, impulsivity and learning and memory disability, among others. To test the hypothesis that dopamine signaling is one of the main factors underlying these impairments, a new atypical dopamine transporter (DAT) inhibitor, CE-123 (1, 3 or 10 mg/kg) was assessed for its potential to overcome the ethanol-induced behavioral effects in a rat model of FASD. In the present study, neonatal rats were exposed to alcohol intubations across the neonatal period (postnatal day (PND)4-9, the third trimester equivalent of human gestation) and, after weaning, the animals (male rats) were assigned randomly to three groups. The first group was tested at PND21 (hyperactivity test). A second group was tested at PND45 (anxiety test), at PND47 (locomotor activity test), at PND49 (spatial cognitive test in the Barnes maze) and PND50 (reversal learning in the Barnes maze). The third group was tested at PND50 (dopamine receptor mRNA expression). Our results support the hypothesis that dopamine signaling is associated with FASD because the dopamine (D1, D2 and D5) receptor mRNA expression was altered in the striatum, hippocampus and prefrontal cortex in adult rats exposed to ethanol during neonatal period. CE-123 (3 and 10 mg/kg) inhibited the hyperactivity and ameliorated (10 mg/kg) the impairment of reversal learning in alcohol-exposed rats. Thus, these findings provide support that CE-123 may be a useful intervention for same of the deficits associated with neonatal ethanol exposure., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Cognitive processes require striatal activity. The underlying molecular mechanisms are widely unknown. For this reason the striatal transcriptome of young (YM), aged cognitively impaired (OMB), and unimpaired (OMG) male rats was analyzed. The global comparison of transcripts reveal a higher number of differences between OMG and YM as compared to OMB and YM. Hierarchical clustering detects differences in up- and down-regulated gene clusters in OMG and OMB when compared to YM. In OMG we found more single genes to be specifically regulated in this group than in OMB when compared to young. These genes were considered as cognition specific, whereas genes shared in OMG and OMB were considered as age specific. OMB specific up-regulated genes are related to negative control of cell differentiation and transcription (Hopx), to phagocytosis (Cd202) and cell adhesion (Pcdhb21), whereas down-regulated genes are related to associative learning, behavioral fear response and synaptic transmission (Gabra5). OMG specific up-regulated genes are in the context of maintenance of transcription and estrogen receptor signaling (Padi2, Anxa3), signal transduction [Rassf4, Dock8)], sterol regulation (Srebf1), and complement activity (C4a, C4b). Down-regulated genes are related to lipid oxidation reduction processes (Far2) and positive regulation of axon extension (Islr2). These relations were supported by pathway analysis, which reveals cholesterol metabolism processes in both aged group and cholesterol biosynthesis specifically in OMG; adipogenesis and focal adhesion in OMB. In OMG glucuronidation, estrogen metabolism, inflammatory responses and TGF beta signaling where detected as specific for this group. Signal transduction of the sphingosine-1-phospate-receptor (S1P) receptor was the main pathway difference in the comparison of OMB and OMG with downregulated genes in the first group. This difference could also be observed in the OMB vs. YM comparison but not in the OMG vs. YM analysis. Thus, an up-regulation of cognition related genes could be observed in OMG compared to OMB rats. The S1P pathway discriminated between OMB and OMG as well as between OMB and OMG. Since this pathway has been described as essential for cognitive processes in the striatum of mice, it may, among steroid hormone signaling, significantly contribute to the maintenance of cognitive processes in OMG., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Korz, Kremslehner, Maliković, Hussein, Feyissa, Nagelreiter, Smidak, Plasenzotti, Gruber and Lubec.)

Ongoing societal changes in views on the medical and recreational roles of cannabis increased the use of concentrated plant extracts with a Δ9-tetrahydrocannabinol (THC) content of more than 90%. Even though prenatal THC exposure is widely considered adverse for neuronal development, equivalent experimental data for young age cohorts are largely lacking. Here, we administered plant-derived THC (1 or 5 mg/kg) to mice daily during P5-P16 and P5-P35 and monitored its effects on hippocampal neuronal survival and specification by high-resolution imaging and iTRAQ proteomics, respectively. We found that THC indiscriminately affects pyramidal cells and both cannabinoid receptor 1+ (CB1R)+ and CB1R- interneurons by P16. THC particularly disrupted the expression of mitochondrial proteins (complexes I-IV), a change that had persisted even 4 months after the end of drug exposure. This was reflected by a THC-induced loss of membrane integrity occluding mitochondrial respiration and could be partially or completely rescued by pH stabilization, antioxidants, bypassed glycolysis, and targeting either mitochondrial soluble adenylyl cyclase or the mitochondrial voltage-dependent anion channel. Overall, THC exposure during infancy induces significant and long-lasting reorganization of neuronal circuits through mechanisms that, in large part, render cellular bioenergetics insufficient to sustain key developmental processes in otherwise healthy neurons.

Rationale: Atypical dopamine (DA) transport blockers such as modafinil and its analogs may be useful for treating motivational symptoms of depression and other disorders. Previous research has shown that the DA depleting agent tetrabenazine can reliably induce motivational deficits in rats, as evidenced by a shift towards a low-effort bias in effort-based choice tasks. This is consistent with human studies showing that people with major depression show a bias towards low-effort activities., Objectives: Recent studies demonstrated that the atypical DA transport (DAT) inhibitor (S)-CE-123 reversed tetrabenazine-induced motivational deficits, increased progressive ratio (PROG) lever pressing, and increased extracellular DA in the nucleus accumbens. In the present studies, a recently synthesized modafinil analog, (S, S)-CE-158, was assessed in a series of neurochemical and behavioral studies in rats., Results: (S, S)-CE-158 demonstrated the ability to reverse the effort-related effects of tetrabenazine and increase selection of high-effort PROG lever pressing in rats tested on PROG/chow feeding choice task. (S, S)-CE-158 showed a high selectivity for inhibiting DAT compared with other monoamine transporters, and systemic administration of (S, S)-CE-158 increased extracellular DA in the nucleus accumbens during the behaviorally active time course, which is consistent with the effects of (S)-CE-123 and other DAT inhibitors that enhance high-effort responding., Conclusions: These studies provide an initial neurochemical characterization of a novel atypical DAT inhibitor, and demonstrate that this compound is active in models of effort-related choice. This research could contribute to the development of novel compounds for the treatment of motivational dysfunctions in humans.