AUTONOMIC AND SENSORY INNERVATION OF CAT MOLAR GLAND AND BLOOD-VESSELS IN THE LOWER LIP, GINGIVA AND CHEEK

Innervation of the molar gland and blood vessels in the lower lip, gin giva and cheek mucous membrane was investigated in the cat with the ai d of whole mount acetylthiocholinesterase (WATChE) histochemistry and retrograde neuronal tracing methods with horseradish peroxidase (HRP) and HRP-conjugated wheat germ agglutinin (WGA-HRP). The molar gland wa s found to be supplied from the buccal nerve and branches of the myloh yoid nerve on the basis of microdissection of WATChE-stained mandibula r preparations under a dissecting microscope. The rostral half of the lower lip-gingiva was innervated by mental branches from the inferior alveolar nerve. The caudal half of the lower lip-gingiva and cheek muc ous membrane were observed to be supplied from the buccal nerve. Follo wing injections of HRP/WGA-HRP into the molar gland, lower lip-gingiva and cheek, many retrogradely labeled ganglion neurons were observed i n the ipsilateral main and accessory otic ganglia, superior cervical g anglion and mandibular division of the trigeminal ganglion. In the pte rygopalatine ganglion, a small number of positive neurons were found, but in a few cases in which the injected tracer was restricted to the lower lip-gingiva and anterior half of the molar gland, labeled neuron s were not detected in the main ganglion nor in its accessory microgan glia. These findings indicate that the cat molar gland receives a post ganglionic parasympathetic supply from the otic ganglia, postganglioni c sympathetic input from the superior cervical ganglion and sensory in nervation from the trigeminal ganglion by way of the buccal nerve and mylohyoid nerve. Vessels in the rostral half of the lower lip-gingiva receive the same inputs from the inferior alveolar nerve, and vessels in the caudal half receive inputs from the buccal nerve. The vessels i n the cheek mucous membrane receive dual parasympathetic supplies from the otic ganglia and the pterygopalatine ganglion by way of the bucca l nerve.