Central corticosteroid receptors involvement in the agonistic behavior and behavioral reactivity in a paradigm of social stress

CALVO N, CALFA G, M VOLOSIN

Congreso; XVth National Meeting of the Argentine Society for Neurochemistry; 2000

Sociedad Argentina de Neuroquimica

This study evaluated the central corticosterone modulation of the strategies exhibited by intruder rats during a social confrontation and of its behavioral sequelae in an open field test. During the confrontation, the intruder exhibited a supine posture (submissive) or continuing freezing (Inactive) and then it is submitted to psychosocial stress. The open field test was performed 18 hours later. The icv microinfusion (100ng/2μl) of MR (A-MR) or GR (A-GR) corticosteroid receptors antagonists was performed before the confrontation of the behavioral test. The frequency of episodes and the total freezing time of Inactive intruders were higher than that in Submissive rats, though both received similar offensive levels from the residents. Despite the different strategies during social stress, both groups showed a decrease of the peripheral locomotion in the open field. The A-MR or AGR infusion before the open field did not induce changes in the intruders behavioral pattern. In contrast, A-MR infusion before social stress increased the number of vocalizations during the confrontation and normalized the behavioral response. Therefore, it can be conclude that the MR blockade would affect the perception of the threatening situation with long term effects on the behavioral reactivity.