Electrical stimulation of the hippocampal formation: Behavioral and bioelectrical effects

Hippocampal slow wave activity was recorded in freely moving rats and it is suggested that the hippocampal formation plays a role in the control of voluntary movements but does not control more automatic movements such as shivering or licking.

Abstract

Hippocampal slow wave activity was recorded in freely moving rats. Rhythmical slow activity (RSA) was present during walking, jumping, struggling, head movement, and bar-pressing (voluntary behavior), but was usually absent during behavioral immobility in the alert state or during face-washing, licking, scratching, or shivering (more automatic behavior). Electrical stimulation of points in the dentate gyrus—CA4 are produced short latency evoked potentials bilaterally in the hippocampus. These potentials supplanted the normal RSA pattern, and concomitantly, behaviors normally accompanied by RSA were abruptly halted (behavioral arrest). Shivering and licking, on the other hand, were not reliably affected by dentate stimulation. It is suggested that the hippocampal formation plays a role in the control of voluntary movements such as walking or manipulation but does not control more automatic movements such as shivering or licking.