[Localization of corticoliberin receptors in the rat brain]

Using the in situ hybridization, a distribution of corticotropin-releasing hormone (CRH) receptors CRH-1 and CRH-2 in the rat brain has been studied. Brain levels of CRH-1 mRNA were higher than the those of CRH-2 mRNA. Most intensive CRH-1 gene expression was observed in the forebrain, including neocortex, archicortex, paleocortex and cerebellar cortex. In addition, significant CRH-1 mRNA expression was detected in the red nucleus, pontine nucleus, cochlear nucleus and reticular tegmental nucleus. CRH-2 mRNA was intensively expressed in the olfactory structures, corticomedial amygdala, CA1-CA4 of hippocampus, ventramedial hypothalamus and several modullar nuclei. Moderate CRH-2 mRNA level were seen in the dorsomedial neostriatum. The findings indicate that within the brain two types of CRH receptors are widely expressed. A distinct pattern of CRH-1 and CRH-2 expression in the brain appears to underline the functional specifics of the CRH actions in brain structures.