CONSUMMATORY SUCCESSIVE NEGATIVE CONTRAST AND CONSUMMATORY EXTINCTION IN ADULT MALE RATS PREVIOUSLY EXPOSED TO NEONATAL CHRONIC STRESS.

RUETTI E; GONZÁLEZ JATUFF A; JUSTEL N, TORRECILLA, M; MUSTACA A

LEARNING AND MOTIVATION

Año: 2008

0023-9690

Mild neonatal stress has proven effective in stimulating both physical and neurochemical development and in reducing behavioral and hormonal responsiveness to an aversive stimulus. In the present study adult male rats subjected to neonatal chronic mild stress were exposed to two experimental situations related to frustrative nonreward: consummatory successive negative contrast (cSNC) and consummatory extinction (cE). Stressed rats that had access to a 32% sucrose solution and were then downshifted to a 4% solution exhibited a faster recovery from cSNC (Experiment 1), and a faster cE when downshifted to an empty tube, relative to nonstressed control rats. These findings suggest that rats chronically exposed to neonatal mild stress quickly adjust their behavior in stressful situations involving the surprising omission of an expected reward. These results are discussed in relation to Amsel´s frustration theory and Gray’s fear=frustration hypothesis.           Keywords: Frustration; Consummatory successive negative contrast; Consummatory extinction; Neonatal chronic stress; Rats.