Changes in noise-maintained behavior following septal forebrain lesions in the albino rat.

Abstract

Recent work by Brady and Nauta demonstrated that lesions in the septal region of the albino rat was followed by rather typical behavior. The characteristic syndrome described by these investigations included the following symptoms: an exaggerated startle response to auditory and tactile stimuli, squealing and biting if handled, freezing after a startle reaction, a peculiar hopping with a rabbit-like gait, a so-called magnet-reaction to an object rotated in front of its nose, and squealing when the fir of its surface was manipulated. The appearance of the syndrome following surgery was only a matte of hours, and it was dramatically different from the preoperative behavior of the animal. Brady and Nauta rated the animals daily for the presence of the symptoms, and found that the duration of the syndrome ranged from about 12 to 60 days. In a preliminary study in the Boston University laboratory it was found that if the hippocampus was bilaterally severed in the caudal aspect the characteristic behavioral symptoms did not appear. However, if the lesion included the rostral tip of the hippocampus and the septal region the syndrome appeared. With Brady and Nauta's findings corroborating to this extent, it was decided that it was necessary to study objectively certain features of the syndrome, and to attempt to further delimit the site of the lesion. [TRUNCATED]