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Updated: Aug 17, 2026

GABA-activated Single-channel and Tonic Currents in Rat Brain Slices
Published on: July 17, 2011
Activation of adenosine A1 and A2 receptors differentially modulates calcium channels and glycinergic synaptic
1Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle 98195.
Abstract:
Multiple types of calcium channels are responsible for calcium influx that triggers transmitter release in the mammalian CNS. To test the contribution of each calcium channel type on synaptic modulation, we recorded calcium currents from somata of presynaptic interneurons and unitary glycinergic postsynaptic currents in the rat brainstem. In interneuron somata, A1 receptor activation inhibited predominantly N-type (omega-conotoxin GVIA-sensitive) and, to a lesser extent, P-type (omega-agatoxin IVA-sensitive) channels. At the presynaptic terminal, N- and P-type channels mediated synaptic transmission. omega-CgTx occluded synaptic inhibition by A1 receptor activation, suggesting that synaptic inhibition was mediated predominantly by N-type channel inhibition. A2 receptor activation facilitated synaptic transmission, probably through potentiation of P-type channels at the presynaptic terminal.
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