DRD2 and schizophrenia: Especially, the cholinergic system is of interest as a treatment for gating deficits in schizophrenia, as the inhibitory interneurons contain, next to the dopamine D2 receptors, α7 nicotinic acetylcholine receptors which upon activation stimulate GABA (γ-aminobutyric acid) release (e.g., Young and Geyer 2013; see Fig. 1).