Do All Motoneurons Innervating Canine Intrinsic Laryngeal Muscles Contain Calcitonin Gene-Related Peptide?

Abstract

Cholera toxin B-Gold, a new retrograde tracer, allows simultaneous observations of the retrograded tracer and immunoreactivity of calcitonin gene-related peptide (CGRP) in a single cell on a single section. Application of this tracer revealed the distinct ratio of the CGRP containing motoneurons innervating the canine intrinsic laryngeal muscles. The ratios of the CGRP containing motoneurons innervating the cricothyroid muscle, thyroarytenoid muscle and posterior cricoarytenoid muscle were 93.0%, 71.9% and 85.5%, respectively. These differences may reflect the special property of each muscle.