Serotonin and vasopressin interact in the hypothalamus to control communicative behavior

The present study investigated whether serotonin (5-HT) agonists could inhibit the ability of arginine-vasopressin (AVP) to induce a form of scent marking called flank marking by their actions in the medial preoptic-anterior hypothalamus (MPOA-AH). DOI, a 5-HT2A,2B,2C receptor agonist, did not inhibit AVP-induced flank marking, but mCPP a 5-HT2A antagonist and 5-HT2B,2C agonist inhibited AVP-induced flank marking. In addition, the finding that 8-OH-DPAT, CGS-12066A and SC53116 also inhibited AVP-induced flank marking suggests that 5-HT could also inhibit flank marking by acting through 5-HT1A, 5-HT7,5-HTIB and/or 5-HT4 receptor subtypes. These data support the hypothesis that 5-HT acts within the MPOA-AH to inhibit the ability of AVP to induce flank marking. NeuroReport 13:931-933 (C) 2002 Lippincott Williams Wilkins.