Fig. 4.

Immunohistochemical localization of GABA and α7 expression in cultured hippocampal neurons. A, Phase-contrast cells dissociated from P5 rat hippocampus and cultured for 8 d in vitro. B, Same field asA, viewed with FITC optics. The large neuron is labeled (green) with anti-GABA antibodies. The smaller neurons are not labeled. C, Same field viewed with rhodamine optics. The large neuron and one small neuron are labeled (red) with an antibody against the α7 subunit.D, Anti-GABA and anti-α7 images superimposed. Areas of overlap appear yellow. Note that the α7-expressing small neuron was negative for GABA expression. D, Inset, Enlarged views of boxed area. Synaptic localization of α7 subunits is suggested by the hot spots of α7 subunits on GABAergic neurites.