Stria terminalis lesions attenuate the effects of posttraining oxotremorine and atropine on retention

Abstract

In these experiments, we examined the effects of posttraining administration of the cholinergic agonist oxotremorine and the cholinergic antagonist atropine on retention in rats with lesions of the stria terminalis (ST). Male Sprague-Dawley rats, with either sham or bilateral ST lesions, were trained in a one-trial step-through inhibitory-avoidance task and a Y-maze discrimination task. Immediately after training on each task, they received i.p. injections of saline, oxotremorine (50.0 μg/kg), or atropine (3.0 mg/kg). Retention of each task was tested 1 week following training. Lesions of the ST did not affect retention of either task in otherwise untreated animals, but blocked both the memory-enhancing effect of oxotremorine and the memory-impairing effect of atropine. These findings suggest that activation of pathways within the ST is involved in cholinergic influences on memory, and are consistent with the view that the amygdaloid complex is involved in integrating neuromodulatory influences on memory storage.