INS and early-onset autosomal dominant Alzheimer disease: Based on the observation that neurodegenerative diseases of the brain and retina share several underlying pathological changes, including oxidative stress and neuroinflammation (Cuenca et al., 2014; de la Rosa and Hernández-Sánchez, 2019), we investigated the effects of injection of AAV vector bearing the human proinsulin gene in the SAMP8 mouse, a model of precocious brain senescence that exhibits several Alzheimer’s disease-like traits (Corpas et al., 2017).