However, levels of [H-3]mesulergine binding to 5-HT2C receptors were increased by approximately 70% in the dorsal hippocampus of rats with serotonin depletion in this region, while those in the ventral hippocampus were unaffected. Therefore, despite intact baseline PPI, abnormal PPI regulation in rats with >70% serotonin depletion in the hippocampus was unmasked by acute risperidone KU-60019 treatment. Selective upregulation of 5-HT2C receptors

in the dorsal, but not ventral, hippocampus of these lesioned rats suggests that hippocampal 5-HT2C receptors vary in their adaptability to changes in serotonergic tone along the dorsoventral axis. These findings suggest that 5-HT2C receptors in the dorsal hippocampus may contribute to risperidone-induced enhancement of PPI.

This article is part of a Special Issue entitled ‘Serotonin: The New Wave’. (C) 2011 Elsevier Ltd. All rights reserved.”
“Previous work has shown that 5-HT2C receptor agonists and 5-HT2A receptor antagonists reduce impulsive action, as well as the locomotor stimulant effect of psychomotor stimulants. Since psychomotor stimulants also increase impulsive action we examined the effects of the 5-HT2C receptor agonist Ro60-0175, and the 5-HT2A receptor antagonist M100907 on impulsive action induced by amphetamine, cocaine and the NMDA receptor antagonist MK801

(dizocilpine). Impulsive action was measured in adult male Long-Evans rats as premature responding Alvespimycin cell line in the 5-choice serial reaction time (5-CSRT) test. Initially, we determined that amphetamine (0.3 mg/kg), cocaine (15 mg/kg) and MK801 (0.03 mg/kg) induced comparable premature

response rates of approximately 50-70 per session, compared to 10-15 responses under baseline conditions. Each drug and its vehicle were then tested in combination with Ro60-0175 (0.1 and 0.6 mg/kg) or its vehicle, or M100907 (0.5 mg/kg) or its vehicle. At 0.1 mg/kg Ro60-0175 did not modify the effects of amphetamine, cocaine or MK801. In contrast, the 0.6 mg/kg dose reduced premature responses induced by amphetamine, cocaine and MK801. M100907 also reduced premature responding induced by all three of these drugs. In general, treatment with Ro60-0175 or M100907 by itself did not consistently alter any of the selleck chemical other aspects of task performance in the 5-CSRT test including number of trials completed, and accuracy of responding. These data show that activation of 5-HT2C receptors and blockade of 5-HT2A receptors have seemingly similar functional effects on a measure of impulsive action.

This article is part of a Special Issue entitled ‘Serotonin: The New Wave’. (C) 2011 Elsevier Ltd. All rights reserved.”
“Selective serotonin (5-HT) re-uptake inhibitors (SSRIs) are commonly used in the treatment of generalized anxiety disorder in Humans.