Activation of β‐Adrenergic Receptors Stimulates Release of an Inhibitory Transmitter from Astrocytes

: Activation of β‐adrenergic receptors on astrocytes in primary cell culture results in the release of taurine, an inhibitory transmitter. Taurine release occurs via a cyclic AMP‐mediated intracellular pathway, because (a) taurine release and intracellular cyclic AMP accumulation have similar pharmacologies and time courses of activation and (b) N6,O2′‐dibutyryl cyclic AMP stimulates release with a time course similar to that observed with the β‐adrenergic agonist isoproterenol. These results describe a previously unrecognized physiological function of astrocytes in the CNS—receptor‐mediated release of the neuroactive amino acid taurine. This observation indicates that astrocytes may function as local regulators of neuronal activity.