Simpson et al. reported the loss of binding sites for 3[H]nipecotic acid, a non-specific inhibitor of all GABA transporters except BGT1, in AD temporal cortex samples [68], while Nägga et al. reported the preservation of binding sites for 3[H]tiagabine, a specific inhibitor of GAT1 [69]. This evidence concerns the gene SLC6A1 and Alzheimer disease.