The hypoglossal nucleus, which innervates extrinsic and intrinsic musculature of tongue and controlls the elaborate and coordinated tongue movement is composed of ventral (protrudor) and dorsal (retractor) Compartments.

The projection from the hypoglossal nucleus of muscles of tongue in rats was studied with the combined method of HRP tracing and immunocytochemistry.

Integrated genioglossal and phrenic muscle activities were recorded on 87 urethaneanesthetized, vagotomized rabbits to study the effect of ethanol and norepinephrine(NA) injected into nucleus hypoglossus on the potentiating effects of integrated ge-nioglossal and phrenic muscle activities (PIMA).

The cardiovascular effects of melatonin in the anterior hypothalamic area (AHA) have been examined by using microinjection technique and the projections of the AHA which may by involved in the sympathetic output for the cardiovascular activity have been examined by using the horseradish peroxidase (HRP) tract tracing method in the rat.