“…In each case, this rhythmicity is entrained by external cues, and, in turn, the rhythmic signals produced in each area project to downstream regions to provide an entraining signal ( Hastings et al, 1998 ; Granados-Fuentes et al, 2004a , 2006 ; Nolasco et al, 2012 ; Saper, 2013 ). The entraining signals provided by each of these systems have significant implications for behavior, and the rhythms that they provide have been found to be negatively impacted in AD, particularly in the case of the circadian system ( Granados-Fuentes et al, 2011 ; Saper, 2013 ; Musiek et al, 2018 ; Takeuchi et al, 2023 ). Synchrony of rhythmicity within the cells of the SCN and OB is dependent on the neuropeptide VIP, which is a potential shared target by mechanisms of AD ( Aton et al, 2005 ; Oddo, 2012 ; Miller et al, 2014 ; Liu et al, 2018 ; Todd et al, 2020 ).…”