Amygdaloid lesions and behavioral inhibition in the rat.

RATS WITH BILATERAL LESIONS OF THE BASOLATERAL REGION OF THE AMYGDALA WERE IMPAIRED IN PASSIVE AVOIDANCE, DIFFERENTIAL REINFORCEMENT OF LOW RESPONDING (DRL) PERFORMANCE, AND SPATIAL ALTERNATIONS WITHOUT CUES, BUT NOT IN VISUALLY CUED SPATIAL ALTERNATIONS OR GO-NO-GO VISUAL DISCRIMINATIONS AND REVERSALS. EXCEPT FOR A SMALL DEFICIT IN PASSIVE AVOIDANCE, RATS WITH LESIONS IN THE CORTICOMEDIAL REGION OF THE AMYGDALA WERE NOT IMPAIRED IN THESE TASKS. DEFICITS PRODUCED BY BASOLATERAL LESIONS CAN NOT READILY BE ATTRIBUTED TO INCREASED MOTIVATION FOR FOOD OR WATER. RESULTS SUGGEST THAT RATS WITH BASOLATERAL AMYGDALOID LESIONS ARE UNABLE TO INHIBIT ESTABLISHED RESPONSES WHEN THEY MUST DEPEND ON INFORMATION PROVIDED BY INTERNAL CUES. (22 REF.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)