Prepulse Inhibition of the Auditory Startle Reflex Assessment as a Hallmark of Brainstem Sensorimotor Gating Mechanisms

Abstract

When a low-salience stimulus of any type of sensory modality—auditory, visual, tactile—immediately precedes an unexpected startle-like stimulus, such as the acoustic startle reflex, the startle motor reaction becomes less pronounced or is even abolished. This phenomenon is known as prepulse inhibition (PPI), and it provides a quantitative measure of central processing by filtering out irrelevant stimuli. As PPI implies plasticity of a reflex and is related to automatic or attentional processes, depending on the interstimulus intervals, this behavioral paradigm might be considered a potential marker of short- and long-term plasticity. Assessment of PPI is directly related to the examination of neural sensorimotor gating mechanisms, which are plastic-adaptive operations for preventing overstimulation and helping the brain to focus on a specific stimulus among other distracters. Despite their obvious importance in normal brain activity, little is known about the intimate physiology, circuitry, and neurochemistry of sensorimotor gating mechanisms. In this work, we extensively review the current literature focusing on studies that used state-of-the-art techniques to interrogate the neuroanatomy, connectomics, neurotransmitter-receptor functions, and sex-derived differences in the PPI process, and how we can harness it as biological marker in neurological and psychiatric pathology.

Opposite Pathways of Cholinergic Mechanisms of Hypoxic Preconditioning in the Hippocampus: Participation of Nicotinic α7 Receptors and Their Association with the Baseline Level of Startle Prepulse Inhibition

“…PPI is the result of activity in the different brain circuits (brainstem, limbic, cortical, thalamic, strio-pallidary structures) and different synaptic mechanisms [ 36 , 37 , 38 ]. Some groups of patients with neuropsychiatric disorders display a deficiency of PPI.…”

Prepulse Inhibition in Cocaine Addiction and Dual Pathologies

“…Several murine studies have indicated that PPI is modulated by DA [ 52 , 53 , 54 , 55 , 56 ] and that schizophrenia is characterized by dopaminergic dysfunction in the striatum [ 57 , 58 ]. This is consistent with the PPI deficits we observed in DP groups, therefore suggesting altered dopaminergic functioning in these patients and that indirect DA agonists such as amphetamines and cocaine could decrease PPI.…”

The impact of child abuse on the neurobiology of self-processing in depressed adolescents

“…The bilateral cerebellum, lingual gyrus and midbrain support emotion regulation, spatial memory, arousal and sensorimotor gating ( Gomez-Nieto et al, 2020 ; Hernaez-Goni et al, 2010 ). Of interest is the association of chronic abuse with blunted midbrain and lingual gyrus activity ( Table 3 , Supplemental Figure 2 ).…”

“…Of interest is the association of chronic abuse with blunted midbrain and lingual gyrus activity ( Table 3 , Supplemental Figure 2 ). The midbrain supports arousal and sensorimotor gating functions ( Gomez-Nieto et al, 2020 ; Lang and Davis, 2006 ). Interestingly, we found blunted overall startle magnitude in post-institutionalized adopted adolescents versus non-adopted US born controls ( Quevedo et al, 2015 ).…”