The startle reflex is an adaptive behavioral reflex that is elicited by sudden or loud stimuli. Prepulse inhibition (PPI) is a measure of sensorimotor gating where the startle reflex generated by a strong (e.g., loud) stimulus is inhibited by prior presentation of a weaker stimulus from the same sensory modality. Recent evidence indicates that patients with Alzheimer’s dementia exhibit normal acoustic startle response but show reduced PPI as compared to healthy age-matched controls or patients with mild cognitive impairment (Ueki, Goto, Sato, Iso, & Morita, 2006). Accordingly, in the APP + PSEN-1 transgenic mouse model of AD, PPI was shown to be inversely related to Aβ expression in the cortex and HPC (Ewers, Morgan, Gordon, & Woodruff-Pak, 2006). It is not known if there is a relationship between alcohol use and sensorimotor gating in Alzheimer’s disease.
