Figure 3:

A) In tissue from GAD67-GFP mice stained with a GABA antibody tagged with gold particles, the gold particle density overlying GFP-labeled profiles (black bars) is greater than the gold particle overlying RLP profiles (gray bars). B) Percentage of corticotectal terminals (CT) found to contact GABAergic (GABA+, black bars) and nonGABAergic (GABA-, gray bars) dendrites (case 1, n = 101, case 2 n = 113). C) Corticotectal terminals were found to be relatively small profiles (0.38 ± 0.21 μm²) that contacted small dendritic profiles (0.31 ± 0.21 μm²). Contacts on nonGABergic dendrites are indicated with gray dots and contacts on GABAergic dendrites are indicated by black squares. The sizes of GABAergic and nonGABAergic postsynaptic dendrites were not found to be statistically different (Mann Whitney, p = 0.6139). D) In slices from GAD67 mice, the majority of cells that did not contain GFP (GFP-, 67%) responded to photoactivation of corticotectal terminals. In contrast, only 11% of cells that contained GFP in GAD67-GFP mice responded to photoactivation of corticotectal terminals. In slices from C57BL/6J mice, the majority of WFV cells (85%) recorded in C57/BLK6 mice responded to photoactivation of corticotectal terminals. In contrast, 39% of the remaining cells (non-WFV) responded to photoactivation of corticotectal terminals.