233 | Differential effects of dopamine agonism in the nucleus accumbens between conditioned taste aversion and latent inhibition depend on the degree of familiarity with sugar.

Neurochemistry and Neuropharmacology

Author: Nieves Yulisa Ataucusi Vargas | Email: nievesyulisa1211@gmail.com

Yulisa Ataucusi , María-Isabel Miranda

1° Behavioral and Cognitive Neurobiology Department, UNAM-INB

The reward system integrates the sweet taste with positive post-ingestion consequences. This system, activated by dopamine, becomes more active when sweet foods are repeatedly excessively consumed beyond homeostatic needs. The nucleus accumbens shell (NACsh) is a key part of this circuit and acts as a sensor, promoting hedonic feeding. However, the role of dopaminergic activity in the NACsh during the formation and extinction of aversive taste memories needs further detailed study. Accordingly, this research aimed to evaluate the effects of bilateral infusion of the dopaminergic agonist apomorphine in the NACsh before the acquisition of conditioned taste aversion (CTA) and latent inhibition (LI). Groups of Wistar rats were exposed to varying levels of sugar familiarity before CTA acquisition: Novel, familiar, and high-familiar. Each group was divided into two treatment subgroups: control (Dimethyl sulfoxide at 10% in physiological saline; 0.05 ul/0.5 ul) or apomorphine (9 ul/0.5 ul). Our results demonstrate that during the acquisition and retrieval of aversive memory, apomorphine treatment did not affect novelty, familiarity, and high familiarity groups compared to controls. Furthermore, the apomorphine treatment in the novelty group did not enhance CTA extinction. In the familiarity group, it did not increase LI, but it did in the high-familiar group. These outcomes collectively suggest the varying activity of dopamine receptors based on the level of sugar familiarity.