Sensorimotor responsiveness in rats with unilateral superior collicular and amygdaloid lesions.

Abstract

In an experiment with 80 male Long-Evans rats, large unilateral lesions of superior colliculus but not amygdala, resulted in strong ipsiversive progression tendencies and permanent neglects of visual, auditory, and whisker-touch stimuli presented on the contralateral side of the body. Combined collicular-amygdoid lesions also yielded circling behaviors and multimodal neglects that were completely independent of the order or laterality of the amygdaloid lesion. Ss with colliculectomy either neglected or turned away from pinches of the contralateral ear and forepaw. Ss with combined lesions displayed more crossed orientations, and this tendency was greatly potentiated by ipsilateral lesion placement. The nature and time course of the crossed response in rats with sensory neglects is reminiscent of the clinical syndrome described as alloaesthesia or as contralateral sensory displacement. (23 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)