1,720,965 research outputs found
Vagus nerve stimulation induces cells proliferation and changes in neuronal morphology in the rat hippocampus
No full textEffects of withdrawal of low ethanol concentrations on GABAA receptor gene expression in rat cerebellar granule neurons in colture
No full textVoluntary ethanol consumption alters hippocampal GABAA receptor gene expression in C57BL/6J mice
No full textChronic vagus nerve stimulation induces neuronal plasticity in the rat hippocampus
Full text linkVagus nerve stimulation (VNS) is used to treat pharmacotherapy-resistant epilepsy and depression. However, the mechanisms underlying the therapeutic efficacy of VNS remain unclear. We examined the effects of VNS on hippocampal neuronal plasticity and behaviour in rats. Cell proliferation in the hippocampus of rats subjected to acute (3 h) or chronic (1 month) VNS was examined by injection of bromodeoxyuridine (BrdU) and immunohistochemistry. Expression of doublecortin (DCX) and brain-derived neurotrophic factor (BDNF) was evaluated by immunofluorescence staining. The dendritic morphology of DCX+ neurons was measured by Sholl analysis. Our results show that acute VNS induced an increase in the number of BrdU+ cells in the dentate gyrus that was apparent 24 h and 3 wk after treatment. It also induced long-lasting increases in the amount of DCX immunoreactivity and in the number of DCX+ neurons. Neither the number of BrdU+ cells nor the amount of DCX immunoreactivity was increased 3 wk after the cessation of chronic VNS. Chronic VNS induced long-lasting increases in the amount of BDNF immunoreactivity and the number of BDNF+ cells as well as in the dendritic complexity of DCX+ neurons in the hippocampus. In contrast to chronic imipramine treatment, chronic VNS had no effect on the behaviour of rats in the forced swim or elevated plus-maze tests. Both chronic and acute VNS induced persistent changes in hippocampal neurons that may play a key role in the therapeutic efficacy of VNS. However, these changes were not associated with evident behavioural alterations characteristic of an antidepressant or anxiolytic action
Altered stress responsiveness and hypothalamic-pituitary-adrenal axis function in male rat offspring of socially isolated parents
No full textSocial isolation in male rats at weaning results in reduced basal levels of the neuroactive steroid 3α,5α-tetrahydroprogesterone (3α,5α-TH PROG) in the brain and plasma as well as increased anxiety-like behavior. We now show that socially isolated female rats also manifest a reduced basal cerebrocortical concentration of 3α,5α-TH PROG as well as an anxiety-like profile in the elevated plus-maze and Vogel conflict tests compared with group-housed controls. In contrast, despite the fact that they were raised under normal conditions, adult male offspring of male and female rats subjected to social isolation before mating exhibited an increased basal cerebrocortical level of 3α,5α-TH PROG but no difference in emotional reactivity compared with the offspring of group-housed parents. These animals also showed an increased basal activity of the hypothalamic-pituitary-adrenal (HPA) axis as well as reduced abundance of corticotropin-releasing factor (CRF) in the hypothalamus and of CRF receptor type 1 in the pituitary. Moreover, negative feedback regulation of HPA axis activity by glucocorticoid was enhanced in association with up-regulation of glucocorticoid receptor expression in the hippocampus. There was also attenuation of corticosterone release induced by foot-shock stress in the offspring of socially isolated parents. The increase in the brain concentration of 3α,5α-TH PROG induced by acute stress was also blunted in these animals. Our results thus show that a stressful experience before mating can influence neuroendocrine signaling in the next generation
Effects of vagus nerve stimulation on BDNF gene expression and hippocampal plasticity in the rat
No full textLack of antidepressant like behavioral effects of chronic vagus nerve stimulation in the rat despite neurochemical end molecular antidepressant like effects
No full textReduction in rat body weight and fat mass without affecting food intake induced by vagus nerve stimulation
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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