Cognitive effects of dopaminergic and glutamatergic blockade in nucleus accumbens in pigeons.

GARGIULO, P.A.; ACERBO, M.J.; KRUG, I.; DELIUS, J.D.

PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR

Elsevier

Año: 2005 p. 732 - 739

0091-3057

Gargiulo, P.A.; Acerbo, M.J.; Krug, I.; Delius, J.D. Pharmacology, Biochemistry and Behavior (2005) 81: 732-739. In earlier studies it was found that glutamatergic transmission within the nucleus accumbens septi is involved in the performance of a learned visusl shape discrimination in pigeons. This study examines what effects several kinds of glutamate and dopamine antagonists have on the same task. Pigeons were trained with the relevant discrimination, bilatarally implanted with cannulas into the nucleus accumbensand tested after various transmission blockers had been administered intracerebrally. SCH-23390, a D1 dopamine antagonist, at the dose used, had no effect, and and Spiperone, a D2 dopamine and 5HT2a-serotonine antagonist, significantly decreased the error repeat trials. CNQX, a non-NMDA glutamate receptor antagonist, and Cycloleucine, an antagonist of the glycine allosteric site of NMDA receptors, had no effect. CGS-19755, a selective competitive NMDA antagonist, significantly impaired performance by significantly decreasing the percent correct trrials and increasing the error repeat trials. CPPG, a II/III metabotropic glutamate antagonist, remarkably improved performance. MMPG, a III/II metzbotropic glutamate antagonist, at the dose used, did not have any significan effect. The preparation employed may be a useful animal model of percpetual disturbances in schizophrenia. KEY WORDS: Pigeon, Nucleus accumbens, Perception, Learned discrimination, Glutamate antagonists, Dopamine antagonists, Schizophrenia.