β1-Adrenoceptor distribution in the rat brain: An immunohistochemical study

Current knowledge of the central nervous system distribution of the β1-adrenergic receptors (β1-AR) is incomplete. Here we present a general map of the β1-AR distribution in the rat brain. β1-AR-immunoreactivity was detected throughout the entire rat brain, but particularly dense staining was observed in the cerebellar cortex and basal ganglia. Brainstem areas displaying significant β1-AR-immunoreactivity include the ventrolateral medulla, nucleus ambiguus and the nucleus of the solitary tract. Within the hypothalamus, only the paraventricular nucleus and the median eminence (ME) showed β1-AR immunostaining. Numerous β1-AR-immunoreactive cells were also found in the hippocampus, basal ganglia and cerebral cortex. These results extend our knowledge of the expression profile of β1-AR in the central nervous system. The identification of several distinct β1-AR immunoreactive substrates linked with neuropathophysiological roles in cardiovascular disease supports the hypothesis that the therapeutic benefit of β1-AR blockade may be conferred at least in part through central nervous system mechanisms.