Effects of fornix lesions on waking and sleep patterns in white rats

Abstract

Polygraphic 12-hr daytime observation of male albino rats revealed increased spontaneous motor activity by a coronal fornical transection but not by a frontal cortical lesion. Fornicotomy alone affected sleep patterns by reducing the total time spent in slow wave sleep (SWS) and paradoxical sleep (PS) and in frequency of occurrence of SWS and PS and by increasing mean duration in the PS phase and the inter PS-interval. However, fornicotomy failed to affect the ratio of the two sleep phases (PS/SWS) either in total time, frequency of occurrence or duration and it did not alter the rate of tiny muscle twitching in PS. Since hippocampal theta activity was completely eliminated by the fornix lesions, the previously hypothesized relationship between theta activity and behaviors such as voluntary movement and PS is in need of revision. © 1977.