Calcitonin gene-related Peptide and choline acetyltransferase colocalization in the human vestibular periphery.
Within the vestibular system, calcitonin gene-related peptide (CGRP) has been localized in the efferent terminals and their brainstem neuronal cell bodies in several animal models. Presently, very few studies have verified these findings in the vestibular system in adult primates or humans. CGRP immunoreactivity (CGRPi) and its colocalization with choline acetyltransferase immunoreactivity (ChATi) in human vestibular end organs and Scarpa's ganglion were studied using polyclonal antibodies against CGRP and ChAT, at the light-microscopic level. The CGRPi axons ramified to produce numerous CGRPi terminals throughout the neurosensory epithelium of the maculae and cristae, primarily in the basal and midbasal areas. Numerous CGRPi efferent terminals made contact with both type II vestibular hair cells and the afferent chalices surrounding type I vestibular hair cells. All CGRP immunoreactive fibers also exhibited ChATi. As in the animal models, no CGRPi was found within Scarpa's ganglion. This study provides evidence for CGRPi in the human vestibular periphery and validates the biomedical relevance of the current animal models.
Popper
Paul
P
Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Ishiyama
Akira
A
Lopez
Ivan
I
Wackym
Phillip A
PA
D015740:Calcitonin Gene-Related Peptide / Q000235:genetics*; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D046508:Culture Techniques; D015870:Gene Expression / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D013701:Temporal Bone / Q000201:enzymology*; D014725:Vestibular Nerve / Q000201:enzymology*
D002795:Choline O-Acetyltransferase; D015740:Calcitonin Gene-Related Peptide