Unitary GABAergic volume transmission from individual interneurons to astrocytes in the cerebral cortex
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Communication between individual GABAergic cells and their target neurons is mediated by synapses and, in the case of neurogliaform cells (NGFCs), by unitary volume transmission. Effects of non-synaptic volume transmission might involve non-neuronal targets, and astrocytes not receiving GABAergic synapses but expressing GABA receptors are suitable for evaluating this hypothesis. Testing several cortical interneuron types in slices of the rat cerebral cortex, we show selective unitary transmission from NGFCs to astrocytes with an early, GABAA receptor and GABA transporter-mediated component and a late component that results from the activation of GABA transporters and neuronal GABAB receptors. We could not detect Ca2+ influx in astrocytes associated with unitary GABAergic responses. Our experiments identify a presynaptic cell-type-specific, GABA-mediated communication pathway from individual neurons to astrocytes, assigning a role for unitary volume transmission in the control of ionic and neurotransmitter homeostasis.
KeywordsInterneuron GABAA GABAB Neocortex
This work was supported by the ERC INTERIMPACT project and the Hungarian Academy of Sciences (G.T.).
- Dy JG, Brodley CE (2004) Feature selection for unsupervised learning. J Mach Learn Res 5:845–889Google Scholar
- Freund TF, Buzsáki G (1996) Interneurons of the hippocampus. Hippocampus 6:347–470. doi: 10.1002/(SICI)1098-1063(1996)6:4<347:AID-HIPO1>3.0.CO;2-I CrossRefPubMedGoogle Scholar
- Martin SC, Steiger JL, Gravielle MC et al (2004) Differential expression of gamma-aminobutyric acid type B receptor subunit mRNAs in the developing nervous system and receptor coupling to adenylyl cyclase in embryonic neurons. J Comp Neurol 473:16–29. doi: 10.1002/cne.20094 CrossRefPubMedGoogle Scholar
- Vizi ES, Kiss JP (1998) Neurochemistry and pharmacology of the major hippocampal transmitter systems: synaptic and nonsynaptic interactions. Hippocampus 8:566–607. doi: 10.1002/(SICI)1098-1063(1998)8:6<566:AID-HIPO2>3.0.CO;2-W CrossRefPubMedGoogle Scholar