Cortical GABAergic neurons received a range of modulatory inputs that convey diverse signals of brain states through a large family of G-protein coupled receptors (GPCRs). We found that whereas MGE-derived PCPs are characterized by higher levels and larger variety of iGluRs and GABAARs, CGE-derived PCPs express much larger variety of neuromodulatory receptors (Figure 4I–L). For example, although PV and VIP/CCK cells both innervate the perisomatic regions of pyramidal neurons, PVBCs enrich for only a few modulatory receptors (e.g. CCK2R, Oprd1) whereas VIP/CCK cells express multiple GPCRs for serotonin, acetylcholine, norepinephrin, endocannabinoid, adrenaline, NPY and VIP (Figure 4J–L). Considered with their iGluR and GABAAR profiles, the results suggest that, similar to their hippocampal homologs (Armstrong and Soltesz, 2012), cortical PVBCs are recruited by fast and precise excitatory and inhibitory inputs from local cortical sources, whereas CCKBCs are profoundly modulated by subcortical inputs that represent internal drive and behavioral states (Table S7)
