Activation of alpha-2 adrenergic receptors stimulates GABA release by astrocytes.

摘要: Norepinephrine is one of the key neurotransmitters in hippocampus, but its role functioning neuroglial networks remains unclear. Here we show that norepinephrine suppresses NH4 Cl-induced oscillations intracellular Ca2+ concentration ([Ca2+ ]i ) hippocampal neurons. We found inhibitory effect against ammonium-induced [Ca2+ mediated by activation alpha-2 adrenergic receptors. Furthermore, UK 14,304, an agonist receptors, evokes a biphasic elevation minor population astrocytes. This consists initial fast, peak-shaped rise, Giβγ subunit and subsequent PLC-induced mobilization from internal stores, plateau phase, influx extracellular medium through store-operated TRPC3 channels. correlation between response astrocytes suppression The 14,304 abolished presence gallein, inhibitor Gβγ -signaling. In turn, application PLC decreases frequency amplitude neurons does not suppress them. same observed bicuculline, GABA(A) receptor antagonist. demonstrate increases slow outward chloride currents neurons, indicating release GABA Thus, our findings indicate astrocytic receptors stimulates via subunit-associated signaling pathway, contributing to neuronal activity.