Cortical administration of somatostatin (SRIF): effect on sleep and motor behavior.

Cortical administration of SRIF in unrestrained, freely moving rats produced an early activation, stereotyped behavior patterns and later, coordination difficulties often associated with drowsiness. A few animals showed a tendency toward paraplegia-in-extension. A considerable, prolonged alteration in the sleep-waking cycle was also observed. Similar results were obtained in both intact and hypophysectomized animals. Intraperitoneal administration of SRIF induced several other effects in addition to those seen after cortical application. The latter were however, restricted in variety, intensity and duration.