European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
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Eur Neuropsychopharmacol · Dec 2015
Alterations in brain-derived neurotrophic factor (BDNF) and its precursor proBDNF in the brain regions of a learned helplessness rat model and the antidepressant effects of a TrkB agonist and antagonist.
Role of brain-derived neurotrophic factor (BDNF)-TrkB signaling in a learned helplessness (LH) model of depression was investigated. LH rats showed a reduction of BDNF in the medial prefrontal cortex (mPFC), CA3, and dentate gyrus (DG) of the hippocampus, whereas LH rats showed an increase in BDNF in the nucleus accumbens (NAc). Furthermore, levels of proBDNF, a BDNF precursor, were higher in the mPFC, but lower in the NAc, of LH rats. ⋯ Additionally, ANA-12 (0.5mg/kg, i.p.) significantly improved an increased phosphorylation of TrkB in the NAc of LH rats. In conclusion, these results suggest that LH causes depression-like behavior by altering BDNF in the brain regions, and that proBDNF-BDNF processing and transport may be altered in the mPFC-NAc circuit of LH rats. Therefore, TrkB agonists might exert antidepressant effects by stimulating TrkB in the IL, CA3, and DG, while TrkB antagonists might exert antidepressant effects by blocking TrkB in the NAc.
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Eur Neuropsychopharmacol · Nov 2015
Multicenter StudyCognitive correlates of frontoparietal network connectivity 'at rest' in individuals with differential risk for psychotic disorder.
Altered frontoparietal network functional connectivity (FPN-fc) has been associated with neurocognitive dysfunction in individuals with (risk for) psychotic disorder. Cannabis use is associated with cognitive and FPN-fc alterations in healthy individuals, but it is not known whether cannabis exposure moderates the FPN-fc-cognition association. We studied FPN-fc in relation to psychosis risk, as well as the moderating effects of psychosis risk and cannabis use on the association between FPN-fc and (social) cognition. ⋯ In conclusion, besides patient- and sibling-specific FPN-fc alterations, there was evidence for trait-related alterations. FPN-fc-cognition associations were not conditional on familial liability or cannabis use. Lower FPN-fc was associated with lower emotion processing in the total group.
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Eur Neuropsychopharmacol · Nov 2015
Comparative StudyVolumetric MRI study of the habenula in first episode, recurrent and chronic major depression.
The habenula (Hb) can play an important role in major depressive disorder (MDD) as it is a key node between fronto-limbic areas and midbrain monoaminergic structures. In vivo neuroimaging studies have shown reductions in Hb volume in a post-mortem sample of patients with affective disorders but findings in unipolar MDD are not consistent. The current study aimed to investigate whether the Hb volume differed between patients with different stages of unipolar MDD and healthy subjects. ⋯ These findings remained unaltered when controlled for total intracranial volume or medication load. Our results do not support decreased total Hb volumes in unipolar MDD, in patients with first-episode or in patients with long-lasting recurrent or chronic depression. However, the increased Hb-WM volume we observed in women with a first-episode suggests involvement of Hb and its projections in early stages of the recovery process and in the course of MDD.
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Eur Neuropsychopharmacol · Nov 2015
Comparative StudyRespective pharmacological features of neuropathic-like pain evoked by intrathecal BDNF versus sciatic nerve ligation in rats.
Numerous reported data support the idea that Brain Derived Neurotrophic Factor (BDNF) is critically involved in both depression and comorbid pain. The possible direct effect of BDNF on pain mechanisms was assessed here and compared with behavioral/neurobiological features of neuropathic pain caused by chronic constriction injury to the sciatic nerve (CCI-SN). Sprague-Dawley male rats were either injected intrathecally with BDNF (3.0 ng i.t.) or subjected to unilateral CCI-SN. ⋯ A long lasting spinal BDNF overexpression was also observed in BDNF i.t. rats, indicating an autocrine self-induction, with downstream long lasting TrkB-mediated neuropathic-like pain. Accordingly, TrkB blockade appeared as a relevant approach to alleviate not only i.t. BDNF- but also nerve lesion-evoked neuropathic pain.
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Eur Neuropsychopharmacol · Oct 2015
Benzodiazepines and risk of death: Results from two large cohort studies in France and UK.
Benzodiazepines are widely prescribed for the treatment of anxiety or insomnia, but their impact on mortality is still debated. This study investigated the impact of benzodiazepine use on short term mortality. Exposed-unexposed cohorts were constructed with the Clinical Practice Research Datalink (CPRD) in the UK and with the General Sample of Beneficiaries (EGB) in France. ⋯ When considering benzodiazepine use as a time-dependent covariate, adjusted HR for current use at 12 months was 1.03 (0.74-1.44). Using two nationally representative databases, we found a significant while moderate increase in all-cause mortality in relation to benzodiazepines, in a population of incident and mostly occasional users. This issue need to be monitored given the extensive use of these drugs.