Neuropharmacology
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At present, role of the lateral habenula (LHb) calcium-permeable AMPA receptors (CP-AMPARs) in depression is not understood, particularly in Parkinson's disease-related depression. Here we found that lesions of the substantia nigra pars compacta (SNc) in rats induced depressive-like behaviors, and intra-LHb injection of CP-AMPAR antagonist Naspm produced antidepressant-like effects in SNc sham-lesioned and SNc-lesioned rats, however, the doses inducing these effects in SNc-lesioned rats were lower than that of SNc sham-lesioned rats. ⋯ Intra-LHb injection of Naspm inhibited dopaminergic neurons in the anterior ventral tegmental area and serotonergic neurons in the dorsal raphe nucleus and excited dopaminergic neurons in the posterior ventral tegmental area (pVTA) and serotonergic neurons in the median raphe nucleus (MRN), and lesioning the GABAergic rostromedial tegmental nucleus (RMTg) decreased the percentages of excited pVTA dopaminergic neurons and MRN serotonergic neurons. Our findings indicate that blockade of LHb CP-AMPARs produces antidepressant-like effects, which attribute to decreased firing activity of LHb neurons and increased levels of dopamine and serotonin in the mPFC, and provide further evidence that LHb CP-AMPARs regulate the firing activity of pVTA dopaminergic neurons and MRN serotonergic neurons indirectly via the RMTg.
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Emerging evidence indicates that gut microbiota interacts with immune and nervous systems in the host and plays a critical role in the pathogenesis of multiple sclerosis (MS) and many psychiatric disorders such as depression and anxiety. The aim of this study was to explore the influence of gut bacterial depletion from early adolescence on adult immunological and neurobehavioral responses in mice with experimental-autoimmune-encephalomyelitis (EAE). We used an animal model of gut microbiota depletion induced by antibiotics from weaning to adulthood to assess clinical signs, cognitive function and depression-and anxiety-related symptoms in non-EAE and EAE-induced mice. ⋯ However, no significant changes were found in non-EAE mice. Non-EAE and EAE mice treated with antibiotics exhibited increased anxiety-related behaviors, whereas depression-related symptoms and increased hippocampal TNF-α and IL-1β were only observed in EAE-induced mice treated with antibiotics. This study supports the view that depletion of gut microbiota by antibiotics from weaning profoundly impacts adult immunological and neurobehavioral responses.