ABSTRACT
Rats with unilateral LH lesions showed great difficulty performing a contraversive turn to escape shock in a T-maze. Rats that were required to turn to the side ipsilateral to the side of their lesion did not show this performance deficit. The impairment in contraversive responding was shown to dissipate over time. It is proposed that animals with LH lesions do not suffer learning disabilities in escape-avoidance tasks, but can not activate motor behavior directed toward the side contralateral to their lesion.
Subject(s)
Escape Reaction/physiology , Hypothalamus/physiology , Motor Skills/physiology , Animals , Conditioning, Classical/physiology , Female , Hypothalamus/surgery , Rats , Time FactorsABSTRACT
During the height of the contralateral sensorimotor deficit that follows unilateral hypothalamic lesions, rats demonstrate severe performance deficits when tested on a two-way active avoidance task which utilizes a visual conditioned stimulus. This deficit is observed whether or not the ipsilateral or contralateral optic nerve is sectioned in conjunction with the unilateral hypothalamic lesion. With the return of sensorimotor function contralateral to the lesion, animals that had been unable to avoid shock during their debillitated phase demonstrated significant savings when tested on the original task.
