In this immunoelectromicroscopic analysis, calcitonin gene-related peptide (CGRP) -like immunoreactive (CGRPI) fibers were identified to make the synaptic contact with the nerve chalices which surround the type I cells in the vestibular end-organs. But no synaptic contact between CGRPI fibers and type II cells was found. Therefore, it is suggersted that CGRP containing efferent fibers are involved in the regulation of the transmission of the vestibular information from the type I cells.
