Innervation of the carotid body. An experimental quantitative study.

The innervation of the carotid body in the cat was studied by means of light- and electron-microscopic techniques. Sinus nerve resection, glossopharyngeal resection, bilateral cervical sympathectomy, excisions of two nerves, and injection of 6-hydroxydopamine (6-OH-DA) were performed in different groups of animals. It was found that resection of the sinus nerve produces a rapid phase of degeneration of intralobular fibers and synaptic boutons, followed by a reinnervation with a progressive reappearance of these elements.

Innervation of the carotid body, types of nerve endings and their possible significance.

The nerve endings in the carotid body of normal cats are investigated by means of serial sections. Two types of endings not described previously are especially studied: the non-synaptic bouton and the meniscus with prolongations. The first is a small nerve ending with abundant mitochondria and glycogen which is devoid of synaptic vesicles.

Histological study of the operative zone in dogs with parotid gland grafts in the sella turcica.

No remnants of adenohypophyseal tissue were found in 83% of the 70 dogs studied; in 17% of the animals remnants amounting to from 1 to 3% of normal hypophyseal tissue were found. These traces showed significant histological and cytological changes, and were most frequently found located on the floor of the sella turcica at some distance from their usual site. It is doubtful whether these residua have any functional significance, since the hypophysectomized dogs with such remnants had a survival time that corresponded to that of dogs with total hypophysectomy (6 months).