L-type Ca Channels and Charybdotoxin-sensitive Ca-activated K Channels Are Required for Reduction of GABAergic Activity Induced by β2-adrenoceptor in the Prefrontal Cortex

Whereas β2-adrenoceptor (β2-AR) has been reported to reduce GABAergic activity in the prefrontal cortex (PFC), the underlying cellular and molecular mechanisms have not been completely determined. Here, we showed that β2-AR agonist Clenbuterol (Clen) decreased GABAergic transmission onto PFC layer V/VI pyramidal neurons via a presynaptic mechanism without altering postsynaptic GABA receptors. Clen decreased the action potential firing rate but increased the burst afterhyperpolarization (AHP) amplitude in PFC interneurons. Application of L-type Ca channel or charybdotoxin-sensitive Ca-activated K channel inhibitors blocked Clen-induced decreases in action potential firing rate, spontaneous inhibitory postsynaptic current (sIPSC) frequency and Clen-induced enhancement of AHP amplitude, suggesting that the effects of Clen involves L-type Ca Channels and charybdotoxin-sensitive Ca-activated K channels. Our results provide a potential cellular mechanism by which Clen controls GABAergic neuronal activity in PFC.