Table 1 lists the 25 GABAergic candidate genes that were selected for this study. The genes encode for GABA synthesis (GLS, GAD1, GAD2), metabolism (ABAT), vesicle transport (SLC32A1), and re-uptake at the synaptic cleft in neurons (SLC6A1) and glia (SLC6A11). GABBR1 and GABBR2 that encode the GABAB presynaptic and postsynaptic receptors were selected. Genes clustered on chromosomes 4, 5 and 15 that encode the GABAA postsynaptic receptors were included with the exception of GABRA6 that is not expressed at detectable levels in the hippocampus. The trafficking of GABAA receptors is an important component in the regulation of plasticity of inhibitory synapses. The intracellular loop of GABAA receptor subunits provides protein-protein interactive domains involved in regulating receptor synaptic localization and intracellular trafficking For the purposes of this study, the genes encoding the key proteins that regulate synaptic localization were selected from the review by Chen and Olsen, 2007 [27]: GPHN, NSF, UBQLN1, GABARAP, RDX and ZDHHC3 (Table 1).
