The superior and inferior salivatory nuclei in the rat.

The locations of the inferior and superior salivatory nuclei in the rat were determined by bathing the tympanic branch of the glossopharyngeal nerve and the chorda tympani with horseradish peroxidase (HRP) in different series of rats. The results demonstrated that the salivatory nuclei extend from the rostral medulla through the caudal pons. The inferior salivatory nucleus is composed of small to medium-sized neurons located in the ventrolateral portion of the reticular formation. It extends from a level at the rostral border of the nucleus ambiguus to the caudal part of the genu of the facial nerve. The superior salivatory nucleus differs in that it is composed of small to medium-sized neurons located in the dorsolateral portion of the reticular formation. It extends from a level at the caudal border of the facial nucleus through the genu of the facial nerve.