NPY and Alzheimer disease: As shown in AD mice, early-onset hypersynchronous network activity may trigger changes in the hippocampal circuitry, including remodeling of inhibitory interneuron network, NPY ectopic expression, and probably aberrant neurogenesis, leading to progressive deterioration of hippocampal function that culminates in age-dependent cognitive decline (Palop et al., 2007; Palop and Mucke, 2009, 2016; Bezzina et al., 2015).