Neuronal Transmitters (s) having Ach exerted two distinct effects on fast-spiking interneurons: Ach directly depolarized FS interneurons by acting on nondesensitizing soma-dendritic nicotinic receptors. In addition, Ach attenuated the GABAergic inhibition of projection neurons by fast-spiking interneurons through activation of presynaptic muscarinic receptors as Publication facts