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Psicologia: Reflexão e Crítica
On-line version ISSN 1678-7153
BUENO, José Lino Oliveira; COSTA, Valéria Catelli Infantozzi; XAVIER, Gilberto Fernando and DIMA, Leno Luis. The acquisition of a temporal task (DRL) by dentate gyrus-selective colchicine lesioned rats. Psicol. Reflex. Crit. [online]. 2006, vol.19, n.1, pp.159-165. ISSN 1678-7153. http://dx.doi.org/10.1590/S0102-79722006000100021.
Previous studies have shown that dentate gyrus damage render rats less efficient than sham-operated controls in the performance of a differential reinforcement of low rates of responding (DRL-20 s) task acquired prior to the lesion; even though the lesioned rats were able to postpone their responses after a previous bar press, they seem to underestimate time relative to sham-operated controls, which interferes with their performance. This study investigated the effects of multiplesite, intradentate, colchicine injections on the acquisition and performance of a DRL-20 s task in rats not exposed to preoperatory training, i.e., trained after the lesion. Results showed that the lesioned rats improved along repetitive training in the DRL-20 s task; however, relative to the sham-operated controls, their acquisition rate was slower and the level of proficiency achieved was poorer, indicating that damage to the dentate gyrus interferes with temporal discrimination.
Keywords : Temporal discrimination; DRL task acquisition; hippocampus; dentate gyrus.