Hippocampal pyramidal neurons were triple labeled with the GABAa subunit isoform specific antibodies guinea pig anti-a1 (green), rabbit anti-a2 (red) and sheep anti-GAD (blue). An overlay of images from the three separate fluorescence channels shows that the larger GABAAR clusters are aligned postsynaptically to presynaptic GABAergic terminal boutons that have formed onto this pyramidal cell from a neighboring interneuron. The GABAAR clusters present at GABAergic synapses contain both subunit isoforms (white arrows). Many smaller clusters also form in areas not contacted by the interneuron and contain receptors with either a1 (green arrow), a2 (red arrow) or both subunits (yellow arrows). Neurons were cultured for 19d.

Pyramidal neuron in the cerebral cortex of the adult rat that is overexpressing transgenic neuroligin 3 and red fluorescent protein (red) after in utero electroporation. The green fluorescence corresponds to enhanced vGAT expression and GABAergic synaptic vesicles from interneuron axons contacting the pyramidal neurons.