Nägga et al. conducted a study in which they measured the displacement of the selective GAT1 radiolabel [3H]tiagabine by GABA in the human frontal and temporal cortices and the caudate nucleus; it was reported in this study that the total number of presynaptic GAT1 transporters and affinity for GABA were both unaffected in the AD tissue [244]. The gene discussed is SLC6A1; the disease is Alzheimer disease.