title: A light and electron microscopic level analysis of calcitonin gene-related peptide (CGRP) in the spinal cord of the primate: an immunohistochemical study.
abstract: In the present study, the distribution of calcitonin gene-related peptide (CGRP)-stained fibers and varicosities are demonstrated in the lumbar spinal cord of the monkey at the light microscopic level. Immunostained fibers and varicosities form a dense plexus in laminae I, IIo, the reticulated region of lamina V, and in the region of the central canal. The intervaricose fibers consistently measured 1 micron or less in diameter suggesting a population of finely myelinated or unmyelinated fibers. At the electron microscopic level, two types of terminals were labeled: a glomerular type where one CGRP-labeled profile was indented by several unlabeled postsynaptic profiles and an axodendritic type with one or sometimes two postsynaptic elements. The most noteworthy cytologic feature of CGRP-labeled profiles was the presence of many relatively large vesicles with dense cores. These findings are steps towards understanding the synaptic interactions of CGRP in the monkey dorsal horn.
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide; D000882:Haplorhini; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009411:Nerve Endings / Q000378:metabolism / Q000648:ultrastructure; D009412:Nerve Fibers / Q000378:metabolism / Q000648:ultrastructure; D009479:Neuropeptides / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism* / Q000648:ultrastructure; D013569:Synapses / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D009479:Neuropeptides; D015740:Calcitonin Gene-Related Peptide