Prepulse inhibition of the acoustic startle reflex and P50 gating in aging and Alzheimer's disease.

Prepulse inhibition of the acoustic startle reflex and P50 gating in aging and Alzheimer's disease. Ageing Res Rev. 2020 Feb 21;:101028 Authors: Jafari Z, Kolb BE, Mohajerani MH Abstract Inhibition plays a crucial role in many functional domains, such as cognition, emotion, and actions. Studies on cognitive aging demonstrate changes in inhibitory mechanisms are age- and pathology-related. Prepulse inhibition (PPI) is the suppression of an acoustic startle reflex (ASR) to an intense stimulus when a weak prepulse stimulus precedes the startle stimulus. A reduction of PPI is thought to reflect dysfunction of sensorimotor gating which normally suppresses excessive behavioral responses to disruptive stimuli. Both human and rodent studies show age-dependent alterations of PPI of the ASR that are further compromised in Alzheimer's disease (AD). The auditory P50 gating, an index of repetition suppression, also is characterized as a putative electrophysiological biomarker of prodromal AD. This review provides the latest evidence of age- and AD-associated impairment of sensorimotor gating based upon both human and rodent studies, as well as the AD-related disruption of P50 gating in humans. It begins with a concise review of neural networks underlying PPI regulation. Then, evidence of age- and AD-related dysfunction of both PPI and P50 gating is discussed. The attentional/ emotional aspects of sensorimotor gating and the neurotransmitter mecha...
Source: Ageing Research Reviews - Category: Genetics & Stem Cells Authors: Tags: Ageing Res Rev Source Type: research