Facial nerve nucleus in the cat. Further study.

The location of efferent neurons, supplying muscles innervated by facial nerve, was studied in the brain stem of the cat using horseradish peroxidase. One to four microliters of HRP was injected in the frontalis, posterior belly of digastric, platysma, and auricularis superior muscles of the kittens. Their representative locations were determined in the facial nucleus. No direct relation between the amount of HRP injected and the numer of labeled neurons was found. The number of positive cells was between 2 and 661. No labeled neurons were found in nucleus of Vth or any other brain stem nuclei.