Immunocytochemical localization of β-adrenergic receptors in the rat brain

The localization of β-adrenergic receptors (β-AdR) in the rat brain was examined immunocytochemically with antibody against affinity-purified β₂-receptors. This antibody was confirmed to cross-react with β₁-AdR. β-AdR were widely but unevenly distributed in the rat brain. In the forebrain and diencephalon, cells with β-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 β-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 β-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 β-AdR. Considerable immunoreactivity was also found in the parabrachial nucleus and the nucleus of the solitary tract.