Effects of intracerebroventricular administration of 5-HT receptor agonists on the maternal aggression of rats.

This study attempted to analyze the effects of 8-OH-DPAT (8-hydroxy-2-(di-n-propylamino)tetralin), TFMPP (1-(3-trifluoromethyl-phenyl)piperazine hydrochloride), and DOI (1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane) on maternal aggressive behavior. Female Wistar rats were divided into 4 groups of 12 animals each. They received an intracerebroventricular (i.c.v.) injection of: (1) saline, (2) 8-OH-DPAT (20 micrograms/rat), (3) TFMPP (100 micrograms/rat), and (4) DOI (100 micrograms/rat). 5-HT1A (8-OH-DPAT) and 5-HT2 (DOI) receptor agonists decreased the frequency of attack 15 but not 55 min after i.c.v. injection. The 5-HT1B/D receptor agonist (TFMPP), in the dose studied, showed no significant difference as compared to saline. Pup care and non-aggressive social interaction with the intruder were not affected by any drug. These data suggest that 5-HT1A and 5-HT2 receptor agonists can specifically inhibit maternal aggression without affecting maternal care; however, this effect is of short duration.