Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system, causing a hyperpolarization of the membrane through the opening of a Cl- channel associated with the GABAA receptor (GABAA-R) subtype. GABA plasma membrane transporters (GATs) influence synaptic neurotransmission by high-affinity uptake and release of GABA. To date, four distinct GABA transporters have been identified: GAT-1, GAT-2, GAT-3, and BGT-1. GAT-1, the most abundant of the transporters, is found predominantly in neurons, but also in some specialized glia (Minelli et al., 1995). GAT-1 is thought to play a key role in epileptogenesis (Zhao et al. 2003). Anti-GAT1 Western blot of rat hippocampal homogenate showing specific immunolabeling of the~ 67k GAT-1 protein.