VISUAL-DISCRIMINATION IN PIGEONS IMPAIRED BY GLUTAMATERGIC BLOCKADE OF NUCLEUS-ACCUMBENS

The nucleus accumbens septi (Acc) is thought to be involved in the con trol of cognitive processes and to be implicated in the pathophysiolog y of schizophrenia. Because perceptual-cognitive distortions are a cor e symptom in schizophrenia, any evidence that the Acc intervenes in a sensory recognition task in an animal species would be of interest. Pi geons were instrumentally trained to discriminate visual shapes. The a cute effects of drug microinjections into the Acc on the discriminatio n of the training shapes, on the correction responding after errors, a nd on the generalisation to different shapes were examined. The effect s of conduction blockade with lidocaine, glutamatergic blockade with 7 -aminophosphonoheptanoic acid, and dopaminergic stimulation with apomo rphine on behavioural performance were tested. No effects were observe d with lidocaine and apomorphine. A significant and reversible perform ance disruption to near chance levels was obtained after aminophosphon oheptanoic acid injections into the Ace. It appears that a glutamaterg ic blockade of the Acc interferes with the visual discrimination proce sses of pigeons. (C) 1998 Elsevier Science Inc.