Figure 1. Receptor Binding Assay Indicating High Levels of δ-containing GABA_ARs on MGB Neurons:

Representative autoradiographs of [³H] gaboxadol binding in young adult rats. Warm colors (red) indicate higher levels of binding while cooler colors (blue) represent lower levels (referenced to Relative Optical Density spectrum at left). At all three concentrations shown here (75 nM, 125 nM and 250 nM), [³H]gaboxadol binds selectively to GABA_ARs in MGB with little binding in brain regions shown in this coronal section, except for hippocampus and upper layers of neocortex. The MGB and hippocampus are indicated by arrows labeled “MGB” and “HP”, respectively with primary auditory cortex labeled as “A1”.