Functional α7*-nAChRs in acutely dissociated mouse hippocampal interneurons. Aa: Phase contrast microscopic image of acutely dissociated typical interneuron from the rat hippocampal CA1 area. Ab: Biocytin was injected into a recorded interneuron and stained with streptoavidin. Ac: Double-staining of biocytin-injected neuron with GAD 67 antibody. Scale bar for panel Aa = 20 μm, for Ab and Ac = 30 μm. Ba: Unlike pyramidal cells, hippocampal interneurons exhibit relatively high frequency spontaneous action potentials. Bb: α7-nAChR agonist-induced whole-cell currents in an acutely dissociated interneuron (red trace) and a non-interneuron (blue trace), indicating functional α7-nAChRs expressed in these neurons.