Administration of Corticosterone After the First Downshift Trial Enhances Consummatory Successive Negative Contrast.

BENTOSELA, M.; RUETTI, E. M.; MUZIO, R. N.; MUSTACA, A. E.; PAPINI, M. R.

BEHAVIORAL NEUROSCIENCE.

AMER PSYCHOLOGICAL ASSOC

Año: 2006 vol. 120 p. 371 - 376

0735-7044

Rats given access to a 32% sucrose solution and then downshifted to a 4% solution exhibit less contact with the sipper tube than unshifted controls always given access to 4% solution. This phenomenon, called consummatory successive negative contrast, was facilitated in Experiment 1 by a posttrial injection of corticosterone (3 mg/kg) administered immediately after the first downshift trial. Experiment 2 demonstrated that this facilitatory effect of posttrial corticosterone does not occur when administered 3 hr after the first downshift trial. These results support the hypothesis that corticosterone strengthens an aversive emotional component elicited by the surprising downshift in reward magnitude during the initial downshift trial.