Identification of glial cells in the MNTB. (A) Astrocytes and NG2 glia in the MNTB of a GFAP-eGFP transgenic mouse. Images are overlays of five consecutive confocal sections taken 1-μm apart. The images are the overlays of eGFP (green) and Alexa 594 emission (magenta). Note that white color in the NG2 glia (right image) is not colocalization but is due to the z-stack projection. Asterisks indicate neighboring postsynaptic principal neurons. White arrow in the left image indicates weakly eGFP⁺ glia. The scale bar (20 μm) refers to all pictures. (B) Electrophysiological identification of astrocyte and NG2 glia. (Top) Representative current responses from an astrocyte (left) and an NG2 glia (right) evoked by step voltages. Membrane currents were evoked by 50-ms voltage steps ranging from −160 to 40 mV from a holding potential of −70 mV. Scale bars refer to both graphs. (Bottom) Average current–voltage (IV) plots (n = 25). Data are mean ± SD. (C) MNTB glial cells with a complex current pattern and sPSCs are expressing AN2 antigen. Image on the left is an overlay of the two images on the right, showing a single focal plane of an NG2 glia filled with LY through the patch pipette (green), fixed after recording and proceeded for immunostaining with AN2 antibody (magenta; see Materials and methods). The asterisks indicate a neighboring principal neuron. The scale bar (20 μm) refers to all pictures.