Correspondence akos.kulik@physiologie.uni-freiburg.de (Á .K.), imre.vida@charite. de (I.V.) In Brief Booker et al. show that GABA B receptors are highly expressed on somatostatin interneuron dendrites. Rather than activating Kir3 channels, they preferentially co-cluster with, and negatively couple to, L-type calcium channels inhibiting long-term potentiation at excitatory inputs. Booker et al., 2018, Cell Reports 22, 36- channels on SOM-IN dendrites, leading to reduced calcium influx and loss of long-term potentiation at excitatory input synapses onto these INs. These data provide a mechanism by which GABA B Rs can contribute to disinhibition and control the efficacy of extrinsic inputs to hippocampal networks.