Analysis of the action of the neuropeptide-inducing delta-sleep in cats and white rats.

Suboccipital administration of the oligopeptide to adult cats and white rats in a dose of 15 and 20 micrograms/kg induces the appearance of electrographic (delta-sleep) and behavioral sleep within 15-25 min. Administration of the oligopeptide induces a substantial increase in the thresholds of the response of the EEG to phonostimulation. A substantial lag (50-90 min) in the onset of paradoxical sleep is noted, which is considered by the authors as a manifestation of inhibition, exerted by the neuropeptide on the further development of the sleep mechanisms. On the basis of the data obtained it is concluded that natural sleep and that induced by the neuropeptide are nonequivalent.