PSEN1 and amyloidosis: Exenatide (500 μg/kg) administered daily for 9 months promoted beneficial effects on short- and long-term memory performance in presenilin-1 knock-in (PS1-KI) mice, a preclinical model of amyloid-independent neuronal dysfunction, and exenatide (500 μg/kg) was administered daily for 2 months to delay age-dependent cognitive decline in normal adult mice (34, 35).