Binding of HCN channels to GABAB receptors in dopamine neurons of the VTA limits synaptic inhibition and prevents the development of anxiety

During GABAergic synaptic transmission, G protein-coupled GABAB receptors (GBRs) activate K+ channels that prolong the duration of inhibitory postsynaptic potentials (IPSPs). We now show that KCTD16, an auxiliary GBR subunit, anchors hyperpolarization-activated cyclic nucleotide-gated (HCN) channels...

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Main Authors: Enrique Pérez-Garci, Kateryna Pysanenko, Giorgio Rizzi, Florian Studer, Daniel Ulrich, Thorsten Fritzius, Simon Früh, Alessandra Porcu, Valérie Besseyrias, Adolf Melichar, Martin Gassmann, Tania Rinaldi Barkat, Rostislav Tureček, Kelly R. Tan, Bernhard Bettler
Format: Article
Language:English
Published: Elsevier 2025-03-01
Series:Neurobiology of Disease
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Online Access:http://www.sciencedirect.com/science/article/pii/S0969996125000476
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Summary:During GABAergic synaptic transmission, G protein-coupled GABAB receptors (GBRs) activate K+ channels that prolong the duration of inhibitory postsynaptic potentials (IPSPs). We now show that KCTD16, an auxiliary GBR subunit, anchors hyperpolarization-activated cyclic nucleotide-gated (HCN) channels containing HCN2/HCN3 subunits to GBRs. In dopamine neurons of the VTA (DAVTA neurons), this interaction facilitates activation of HCN channels via hyperpolarization during IPSPs, counteracting the GBR-mediated late phase of these IPSPs. Consequently, disruption of the GBR/HCN complex in KCTD16−/− mice leads to prolonged optogenetic inhibition of DAVTA neuron firing. KCTD16−/− mice exhibit increased anxiety-like behavior in response to stress - a behavior replicated by CRISPR/Cas9-mediated KCTD16 ablation in DAVTA neurons or by intra-VTA infusion of an HCN antagonist in wild-type mice. Our findings support that the retention of HCN channels at GABAergic synapses by GBRs in DAVTA neurons provides a negative feedback mechanism that restricts IPSP duration and mitigates the development of anxiety.
ISSN:1095-953X