Glial localization of adenylate-cyclase-coupled beta-adrenoceptors in rat forebrain slices.

Fluorocitrate (FC), a selective inhibitor of glial cell respiration, was used to estimate the extent to which glial cells contain adenylate cyclase-coupled beta-adrenoceptors in rat brain slices. The drug blocked 75-95% of the elevation of cyclic AMP caused by the beta-agonist, isoproterenol, in the 4 forebrain regions sampled (frontal and parietal cortex, caudate nucleus, olfactory tubercle). Intracellular recording of neurons in the treated slices confirmed that they were unaffected by FC. Treatment with the neurotoxin, kainic acid, eliminated all electrophysiological activity but did not affect the cAMP response. The results indicate that glial cells contain the preponderance of adenylate-cyclase-coupled beta-adrenoceptors in slices of the rat forebrain and may constitute an important target of the central noradrenergic system in vivo.