Neurochemical substances in neurons of the canine intrinsic laryngeal muscles.
The localization of vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), catecholamines (CA) and carbon monoxide (CO) in neurons of the intrinsic laryngeal muscles of the dog was investigated using immunohistochemistry. Cells with VIP-like immunoreactivity were found between the striated muscle fibres of the cricothyroid and posterior cricoarytenoid muscles, some aggregated into a ganglion and some solitary. Neurons with immunoreactivity to haem oxygenase-2 (HO-2), an immunohistochemical marker for CO, were also seen. VIP-or HO-2-negative cells also existed in various numbers in the intramuscular ganglia. No CGRP-like immunoreactive neurons were found although CGRP-like immunoreactive varicose fibres were seen in the intramuscular ganglia. No neurons or fibres immunoreactive to tyrosine hydroxylase (TH), the key enzyme in synthesis of CA, were detected. The exact function of these intramuscular ganglia is yet to be clarified, but they may be sensory neurons.
D000818:Animals; D004285:Dogs; D005260:Female; D005724:Ganglia / Q000737:chemistry; D007150:Immunohistochemistry; D007821:Laryngeal Muscles / Q000737:chemistry / Q000294:innervation*; D008297:Male; D009474:Neurons / Q000737:chemistry*; D009479:Neuropeptides / Q000032:analysis*