Postsynaptic 5-HT1A receptors control 5-HT release in the rat medial prefrontal cortex

5-HT1A receptor agonists reduce the neuronal release of 5-hydroxytryptamine (5-HT) by activation of raphe 5-HT1A autoreceptors. Using in vivo microdialysis in unanesthetized rats, we show that the local application of the selective 5-HT1A receptor agonist 8-OH-DPAT decreased the 5-HT output to similar to 50% of controls in medial prefrontal cortex (mPFC) but not in dorsal hippocampus. The decrease in 5-HT output was counteracted by the concurrent application of the selective 5-HT1A receptor antagonist WAY-100635. This agent also reversed the decrease in 5-HT output-elicited by the novel 5-HT1A receptor agonist BAY x 3702 (30 mu M) in mPFC and dorsal raphe nucleus. These results indicate that postsynaptic 5-HT1A receptors in mPFC also participate in the control of serotonergic activity. NeuroReport 10:1441-1445 (C) 1999 Lippincott Williams & Wilkins.