Response to reward change in a model of schizophrenia like behavior produced by postweaning isolation

CUENYA, L.; KAMENTEZKY, G.; MUSTACA, A.

Huerta Grande

Congreso; XXVI Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia; 2011

Isolation rearing from weaning produces long-term changes in behaviour including neophobia, impaired sensorimotor gating, social withdrawal and cognitive inflexibility, which cover the domains affected in schizophrenia. Our aim was to investigate the effect of early isolation (EI) has on the response to the reward change in adult rats. Animals had access to different concentrations of sucrose solutions, and goal tracking time was measured. In the Exp 1 we studied the impact of the EI (post natal day 21-36) on the partial reinforcement effect on the reinforcement devaluation. The EI altered neither the response to incentive devaluation, nor the partial reinforcement effect on the consummatory suppression, but EI animals showed an increase in consumption when the reinforcement was suddenly increased. In Exp 2 we evaluated animals in consummatory successive positive contrast and consummtory extinction (cE). Isolated subjects showed a more lasting positive contrast effect, but animals of both conditions did not differ in cE. These results suggest that EI do not produce major frustration reactions but express an increased euphoria, which is consistent with evidences of a major sensitivity to apetitive rewards and dopaminergic hyperactivity in mesolimbic system of isolated rats.