Phenotypic analysis of hippocampal GABAergic neuronal populations at the overt stages of AD has pointed to selective loss in number or function of their specific sub-types, notably neurons expressing somatostatin (SOM), neuropeptide Y (NPY) (Ramos et al., 2006) and paravalbumin (PV) (Verret et al., 2012). This evidence concerns the gene NPY and Alzheimer disease.