Distribution of calcitonin gene-related peptide in the rat peripheral nervous system with reference to its coexistence with substance P

Localization of calcitonin gene-related peptide in the organ of Corti of the rat: an immunohistochemical study

The localization of calcitonin gene-related peptide (CGRP)-like immunoreactive (CGRPI) structures in the cochlea was examined in the rat using immunocytochemistry. Numerous CGRPI fibers entered the organ of Corti in the intraganglionic spiral bundle and formed a dense fiber patch at the base of the inner hair cells. Much fewer, but still a significant number of CGRPI fibers were seen at the synaptic region of the outer hair cells. Since no immunoreactive cells were seen in the organ of Corti and spinal ganglion, these fibers may be one of the major components of the olivocochlear bundles originated from the superior olivary complex.

Calcitonin gene-related peptidergic projection from the parabrachial area to the forebrain and diencephalon in the rat: an immunohistochemical analysis

We investigated ascending fiber projections of calcitonin gene-related peptide from the parabrachial area to the forebrain and diencephalon in the rat using immunocytochemistry. Destruction of the lateral portion of the dorsal parabrachial area resulted in a marked ipsilateral decrease in the fibers containing calcitonin gene-related peptide in the ventromedial hypothalamic nucleus, indicating that cells containing calcitonin gene-related peptide in the lateral portion of the dorsal parabrachial area projected to the ipsilateral ventromedial hypothalamic nucleus. Destruction of the ventral portion of the parabrachial area resulted in a marked decrease of fibers containing calcitonin gene-related peptide in the bed nucleus of the stria terminalis, the central amygdaloid nucleus and the lateral hypothalamus just medial to the crus cerebri (the far-lateral hypothalamus), and a less marked decrease in the ventromedial thalamic nucleus. This means that there are projections from cells containing calcitonin gene-related peptide in the ventral portion of the parabrachial area to the first three regions just mentioned, and to some extent to the last.