NPY and Alzheimer disease: A previous phenotypic analysis of hippocampal GABAergic neuronal populations at the overt stages of AD pointed to selective loss in number or function of specific sub-types, notably neurons expressing NPY (Ramos et al., 2006; Albuquerque et al., 2015), and PV (Verret et al., 2012; Albuquerque et al., 2015).