European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
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Eur Neuropsychopharmacol · Jan 2014
Vortioxetine dose-dependently reverses 5-HT depletion-induced deficits in spatial working and object recognition memory: a potential role for 5-HT1A receptor agonism and 5-HT3 receptor antagonism.
We previously reported that the investigational multimodal antidepressant, vortioxetine, reversed 5-HT depletion-induced memory deficits while escitalopram and duloxetine did not. The present report studied the effects of vortioxetine and the potential impact of its 5-HT1A receptor agonist and 5-HT3 receptor antagonist properties on 5-HT depletion-induced memory deficits. Recognition and spatial working memory were assessed in the object recognition (OR) and Y-maze spontaneous alternation (SA) tests, respectively. 5-HT depletion was induced in female Long-Evans rats using 4-cholro-DL-phenylalanine methyl ester HCl (PCPA) and receptor occupancies were determined by ex vivo autoradiography. ⋯ Flesinoxan had a MED ≤1.0mg/kg (∼25% 5-HT1A receptor occupancy; SA); only 1.0mg/kg ameliorated deficits in the NOR. Chronic p.o. vortioxetine administration significantly improved memory performance in OR and occupied 95%, 66%, and 9.5% of 5-HT3, 5-HT1B, and 5-HT1A receptors, respectively. Vortioxetine's effects on SA performance may involve 5-HT1A receptor agonism, but not 5-HT3 receptor antagonism, whereas the effects on OR performance may involve 5-HT3 receptor antagonism and 5-HT1A receptor agonism.
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Eur Neuropsychopharmacol · Jan 2014
Orcinol glucoside produces antidepressant effects by blocking the behavioural and neuronal deficits caused by chronic stress.
This study focused on the antidepressant potential of orcinol glucoside (OG) and its possible mechanisms of action. We established a depressed rat model using 3 consecutive weeks of chronic unpredictable mild stress (CUMS). The antidepressant-like effect of OG was revealed using the sucrose preference test, the open field test, the forced swimming test (FST), and the tail suspension test (TST). ⋯ Rats that received OG treatment exhibited reduced serum CORT levels and CRH mRNA expression in the hypothalamus, suggesting that the hyperactivity of the HPA axis in CUMS rats was reversed by OG treatment. Moreover, OG treatment upregulated the protein levels of BDNF and phosphorylated-ERK1/2 in the hippocampus, even above control levels. Our findings suggest that OG improved depressive behaviour in CUMS rats by downregulating HPA axis hyperactivity and increasing BDNF expression and ERK1/2 phosphorylation in the hippocampus.
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Eur Neuropsychopharmacol · Dec 2013
Randomized Controlled TrialThe endocannabinoid system and emotional processing: a pharmacological fMRI study with ∆9-tetrahydrocannabinol.
Various psychiatric disorders such as major depression are associated with abnormalities in emotional processing. Evidence indicating involvement of the endocannabinoid system in emotional processing, and thus potentially in related abnormalities, is increasing. In the present study, we examined the role of the endocannabinoid system in processing of stimuli with a positive and negative emotional content in healthy volunteers. ⋯ These results indicate that THC administration reduces the negative bias in emotional processing. This adds human evidence to support the hypothesis that the endocannabinoid system is involved in modulation of emotional processing. Our findings also suggest a possible role for the endocannabinoid system in abnormal emotional processing, and may thus be relevant for psychiatric disorders such as major depression.
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Eur Neuropsychopharmacol · Nov 2013
Randomized Controlled Trial Comparative StudyImpact of 5-HTTLPR and BDNF polymorphisms on response to sertraline versus transcranial direct current stimulation: implications for the serotonergic system.
Transcranial direct current stimulation (tDCS) has been intensively investigated as a non-pharmacological treatment for major depressive disorder (MDD). While many studies have examined the genetic predictors of antidepressant medications, this issue remains to be investigated for tDCS. In the current study, we evaluated whether the BDNF Val66Met and the 5-HTT (5-HTTLPR) polymorphisms were associated with tDCS antidepressant response. ⋯ A dose-response relationship between active-sham differences with the long allele was also suggested. These results strengthen the role of the serotonergic system in the tDCS antidepressant effects and expand previous findings that reported that tDCS mechanisms of action partially involve serotonergic receptors. Therefore, we hypothesize that tDCS is a neuromodulation technique that acts over depression through the modulation of serotonergic system and that tDCS "top-down" antidepressant effects might not be optimal in brain networks with a hyperactive amygdala inducing bottom-up effects, such as occurs in short-carriers.
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Eur Neuropsychopharmacol · Nov 2013
Randomized Controlled TrialA randomised, double-blind, placebo-controlled, efficacy study of nalmefene, as-needed use, in patients with alcohol dependence.
This study evaluated the efficacy of as-needed use of the opioid system modulator nalmefene in reducing alcohol consumption in patients with alcohol dependence. Seven hundred and eighteen patients (placebo=360; nalmefene=358), ≥ 18 years of age, with a diagnosis of alcohol dependence, ≥ 6 heavy drinking days and an average alcohol consumption ≥ WHO medium drinking risk level in the 4 weeks preceding screening, were randomised (1:1) to 24 weeks of as-needed placebo or nalmefene 18 mg/day. The co- primary efficacy analyses showed a significantly superior effect of nalmefene compared to placebo in the change from baseline to month 6 in heavy drinking days (group difference: -1.7 days/month [95% CI -3.1; -0.4]; p=0.012) and a better but not significant effect in reducing total alcohol consumption (group difference: -5.0 g/day last month [95% CI -10.6; 0.7]; p=0.088). ⋯ Improvements in Clinical Global Impression and reductions in liver enzymes were greater in the nalmefene group than in the placebo group. Adverse events were more common with nalmefene; the incidence of adverse events leading to dropout was similar in both groups. This study provides evidence for the efficacy of nalmefene, which constitutes a new pharmacological treatment paradigm in terms of treatment goal (reduced drinking) and dosing regimen (as-needed), in alcohol dependent patients unable to reduce alcohol consumption on their own.