GABAergic neurons with AMPA GluR1 and GluR2/3 immunoreactivity in the rat striate cortex.

The co-localization of GABA with AMPA receptor subunits GluR1 or GluR2/3 was analysed in the striate cortex of adult rats by post-embedding immunocytochemistry in semithin sections. Adjacent 1 micron semithin sections of four brains were alternately incubated with specific antibodies against GABA and the GluR1 and GluR2/3 subunits. The post-embedding immunocytochemistry showed that 38% of GABAergic neurons contained the GluR1 subunit and 10% contained the GluR2/3 subunits. Previous work has shown GluR1 immunoreactivity in non-pyramidal neurons and GluR2/3 immunoreactivity in pyramidal neurons. However, this study is the first to demonstrate that there are GABAergic neurons co-localized with GluR2/3 AMPA subunits. Additionally, this study provides quantitative estimations of the laminar distribution of GABAergic and non-GABAergic cells containing the AMPA GluR1 and GluR2/3 subunits.