Involvement of cingulate cortex in the formation of defensive behavior in rats.

Changes in behavior patterns in rats during electric stimulation of the ventromedial hypothalamus (the center of defensive behavior) and cingulate cortex were studied. Electric stimulation of the frontomedial cingulate cortex reduced the latency for anxiety and escape reactions during electric stimulation of the ventromedial hypothalamus. Electrolytic destruction of the frontomedial cingulate cortex substantially increased the threshold of escape behavior during stimulation of the ventromedial hypothalamus. These findings demonstrate the involvement of the frontomedial cingulate cortex into the development of defensive (anxiety and escape) behavior in rats.