Immunohistochemical Studies on Calcitonin Gene-related Peptide Cell in Rat Brain

Lee, Heung Sik; Lee, In Se; Kang, Tae Chun; Lee, Bong Hee

Abstract

These studies were performed to identify the localization, and neuronal function of calcitonin gene-related peptide[CGRP] in the neural axis of rat stomach by retrograde tracing and immunohistochemical techniques. After injection of pseudorabies virus Bartha strain[PRV] as tracer between serosa and muscle layer of stomach, the rats were perfused and the brains were removed. PRV-immunoreactive cells were observed in central nucleus of amygdaloid, insular cortex, subfornical organ, bed nucleus of stria terminalis, paraventricular nucleus, organum vasculosum of terminalis, suprachiasmatic nucleus, lateral hypothalamic area, K lliker-Fuse nucleus, parabrachial nucleus, locus ceruleus, A1 noradrenaline area, A5 noradrenaline area, area postrema, dorsal motor nucleus of vagus nerve, nucleus tractus solitarius and raphe nuclei. CGRP-immunoreactive cells are observed in insular cortex, bed nucleus of stria terminalis, paraventricular nucleus, lateral hypothalamic area, parabrachial nucleus, area postrema, nucleus tractus solitarisu, neucleus ambiguus, facial nucleus, hypoglossal nucleus and raphe nuclei. The dobule immunofluorescent study was carried out to examine the coexistence of CGRP and PRV in several nuclei : insular cortex, bed nucleus of stria terminalis, paraventricular nucleus, later hypithalamic area, parabrachial nucleus, area postrema, nucleus tractus solitarius and raphe nuclei. At the results of double immunofluorescent study, we could not observe the double immunoreactive neurons CGRP and PRV in those nuclei but raphe nuclei. These results suggest that CGRP should not have a neural functions in the neurons in nuclei projecting to rat stomach except raphe nuclei.