Sensorimotor Gating and Acoustic Startle Responses in Psychiatric Disorders

Sensorimotor gating is a fundamental neurophysiological mechanism by which the brain filters out irrelevant sensory information, thereby safeguarding cognitive stability and preventing sensory overload. A principal assay of this gating is the prepulse inhibition (PPI) of the acoustic startle response, in which a weak prestimulus transiently attenuates the reflexive motor reaction to a subsequent loud sound. The acoustic startle response itself is a rapid, involuntary contraction of facial and skeletal muscles, mediated by a conserved brainstem circuit that includes cochlear root neurons, the caudal pontine reticular nucleus and spinal motor neurons. Deficits in PPI are a well-established endophenotype of several psychiatric conditions, notably schizophrenia, bipolar disorder, obsessive-compulsive disorder and autism spectrum disorders, and have been linked to dysregulation of dopaminergic, glutamatergic and adenosinergic neurotransmission. Through translational rodent models and human experiments, alterations in PPI have informed our understanding of the neural substrates of psychosis, sensory over-responsivity and attentional dysfunction, and have guided the development of novel pharmacological and neuromodulatory therapies. Globally, research in this field offers promise for objective biomarkers to stratify patients, predict treatment response and accelerate drug discovery in neuropsychiatry.

Research from Nature Portfolio

Recent studies have demonstrated that perceptual separation between a prepulse and a masking stimulus enhances PPI in humans by facilitating selective attention to the prepulse. Functional measures of early cortical processing, specifically increases in the N1 and P2 components of auditory evoked potentials, correlate positively with the degree of PPI enhancement. These findings indicate that spatial auditory segregation strengthens the signal-to-noise ratio of the prepulse within temporal auditory cortical fields, and underscore the role of top-down attentional modulation in shaping subcortical sensorimotor gating mechanisms.

Sensorimotor Gating and Acoustic Startle Responses in Psychiatric Disorders publication trend

The graph below shows the total number of articles in sensorimotor gating and acoustic startle responses in psychiatric disorders across all publications each year (not limited to Nature Index journals).

Technical terms

Acoustic startle response: A rapid, involuntary motor reaction evoked by a sudden loud auditory stimulus.

Prepulse inhibition (PPI): The reduction of startle magnitude when a weak prestimulus precedes a startling stimulus, indexing sensorimotor gating.

Sensorimotor gating: The neural mechanism that filters out irrelevant sensory inputs to protect ongoing cognitive and motor processes.

Startle scaling: The modulation of the amplitude of the startle reflex, reflecting changes in motor output.

Sound scaling: The alteration in auditory signal processing that shifts the relationship between stimulus intensity and response magnitude.

References

1. Neural correlates of perceptual separation-induced enhancement of prepulse inhibition of startle in humans. Scientific Reports (2018).
2. A review of the neural basis underlying the acoustic startle response with a focus on recent developments in mammals. Neuroscience & Biobehavioral Reviews (2023).
3. Assessing the Cntnap2 knockout rat prepulse inhibition deficit through prepulse scaling of the baseline startle response curve. Translational Psychiatry (2023).
4. Robust and replicable measurement for prepulse inhibition of the acoustic startle response. Molecular Psychiatry (2020).