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“There has been controversy over use of selective serotonin reuptake inhibitors (SSRIs) to treat affective
disorders in children and adolescents due to clinical reports of increased risk for suicidal ideation and behavior during treatment, and animal studies showing Elafibranor nmr changes in adult anxiety- and depressive-like behaviors after repeated treatment during adolescence. However, the acute effect of serotonergic drugs on affective behavior during adolescence is poorly understood. We investigated serotonergic modulation of anxiety-like behavior in adolescent (PN28-32) and adult (PN67-73) male rats using the SSRI fluoxetine, the 5-HT1A agonist 8-OH DPAT; and the 5-HT2 agonist mCPP. Acute treatment with fluoxetine (10 mg/kg, i.p.) produced greater anxiogenic effects in adults than adolescents in the light/dark (LD) test for anxiety-like behavior, but fluoxetine (2.5, 5, and 10 mg/kg, i.p.) increased extracellular S3I-201 datasheet serotonin in the medial prefrontal cortex similarly in both ages. Adults were also more sensitive to the anxiogenic effects of
8-OH DPAT (0.25 and 0.5 mg/kg, i.p.), but not mCPP (0.5 and 1 mg/kg, i.p.), in the LB test. Fluoxetine (10 mg/kg) stimulated greater increases in c-Fos expression across the extended amygdala in adults than in adolescents, and 8-OH DPAT (0.5 mg/kg) produced greater increases in c-Fos in
the lateral orbital cortex and central nucleus of the amygdala in adults. These data show that lower anxiogenic effects of acute SSRIs in adolescents are associated with lesser activation of cortical and amygdala brain regions. This immaturity could RSL3 concentration contribute to the different profile of behavioral effects observed in adolescents and adults treated with SSRls. (C) 2013 Elsevier Ltd. All rights reserved.”
“Three experiments examined the effect of response-outcome contingencies on human ratings of causal efficacy and demonstrated that such ratings transfer to novel situations through derived stimulus relations. Efficacy ratings generally followed the delta probability rule when positive response-outcome contingencies were employed (Experiment 1) and when some outcomes were not contingent on participants’ responses (Experiment 2). Experiment 3 employed a negative response-outcome contingency and manipulated performance expectancies in the task. All three groups overestimated their causal efficacy ratings. A learned helplessness effect was observed when the response-outcomes were uncontrollable and in the high-expectancy group when participants’ performance in the task was worse than they had expected. In all experiments, ratings transferred to a stimulus presented during the task and often generalized to novel stimuli through derived relations.