PROTECTIVE ACTIONS OF THE 5-HT2A 2C, RECEPTOR AGONIST, DOI, ON 5-HT1ARECEPTOR-MEDIATED INHIBITION OF LORDOSIS BEHAVIOR/

Sexually receptive proestrous rats were infused bilaterally into the v entromedial nucleus of the hypothalamus (VMN) with 200 ng of 8-hydroxy -2-(di-n-propylamino) tetralin (8-OH-DPAT), 1000 or 2000 ng of 5-metho xy-3-(di-n-propylamino) chroman (5-MEO-DPAC), or 1000 or 2000 ng of se rotonin (5-HT) plus or minus the 5-HT2A/2C agonist, (2,5-dimethoxy-4-i odophenyl)-2-aminopropane HCl (DOI). DOI protected against the lordosi s-inhibiting effects of 5-HT and each of the 5-HT1A agonists. These re sults substantiate a prior report that 2000 ng DOI could protect again st the lordosis-inhibiting action of 200 ng 8-OH-DPAT and demonstrate that such protection is not unique to a single 5-HT1A agonist. Consequ ently, these results strengthen evidence that functionally significant interactions occur among 5-HT receptors within the VMN. (C) 1996 Else vier Science Ltd.