Immunocytochemical localization of beta-adrenergic receptors in the rat brain.

The localization of beta-adrenergic receptors (beta-AdR) in the rat brain was examined immunocytochemically with antibody against affinity-purified beta 2-receptors. This antibody was confirmed to cross-react with beta 1-AdR. beta-AdR were widely but unevenly distributed in the rat brain. In the forebrain and diencephalon, cells with beta-AdR were abundant in the cerebral cortex, hippocampus, and various hypothalamic nuclei other than the ventromedial hypothalamic nucleus and the suprachiasmatic nucleus. Few or no cells with beta-AdR were found in the thalamus except in the lateral and medial geniculate nucleus, habenular nucleus and paraventricular thalamic nucleus. The striatum, globus pallidus, and accumbens nucleus also contained few beta-AdR. In the lower brainstem, areas related to auditory function, such as the inferior colliculus, the nucleus of the lateral lemniscus and the cochlear nuclei, as well as areas related to cerebellar function, such as the reticulotegmental nucleus of the pons, the pontine nuclei, the lateral reticular nucleus and the inferior olive, were rich in beta-AdR. Considerable immunoreactivity was also found in the parabrachial nucleus and the nucleus of the solitary tract.