Measurement notes
Calculate PPI from matched pulse-alone and prepulse-plus-pulse trials. Report each prepulse intensity separately when possible because a single average can hide intensity-dependent gating or baseline startle floor effects.
Endpoint methods library
Sensorimotor gating endpoint
Prepulse inhibition
Percent reduction in startle response when a weak prepulse precedes a stronger startling pulse.
Unit
percent inhibition
Readout
Percent reduction of startle amplitude on prepulse-plus-pulse trials versus pulse-alone trials
Assays
Acoustic startle PPI, pharmacology, schizophrenia models, autism models, startle gating screens
Decision summary
Use prepulse inhibition when the experiment asks about sensorimotor gating or modulation of the acoustic startle reflex. The endpoint is strongest when pulse-alone amplitude, prepulse intensities, inter-stimulus intervals, background noise, hearing status, and baseline movement are reported together.
| Primary value | Percent reduction of startle amplitude on prepulse-plus-pulse trials versus pulse-alone trials |
|---|---|
| Common units | Percent PPI at each prepulse intensity or inter-stimulus interval |
| Compatible assays | Acoustic startle PPI, pharmacology, schizophrenia models, autism models, startle gating screens |
| Required boundary | Pulse intensity, prepulse intensity, interval, response window, and formula denominator |
| Do not infer alone | Cognition, attention, schizophrenia-like state, hearing acuity, or startle capacity |
Interpretation limit
Reduced PPI can support impaired sensorimotor gating, but it can also reflect low pulse-alone amplitude, hearing deficits, high baseline movement, trial noise, prepulse salience, drug-induced sedation, or strain-specific startle profiles.
Data capture
Store animal ID, trial type, pulse intensity, prepulse intensity, inter-stimulus interval, background noise, pulse-alone amplitude, prepulse-plus-pulse amplitude, percent PPI, baseline movement, chamber ID, and exclusion flags.
Confound checks
- Low or saturated pulse-alone startle amplitude compressing the PPI denominator.
- Hearing impairment or prepulse intensity below detection threshold.
- Baseline movement, chamber noise, or sensor gain differences.
- Trial-order effects, habituation, sensitization, and inter-trial interval variation.
- Sedation, motor impairment, body weight, sex, strain, or age effects.
Reporting checklist
- Pulse intensity, prepulse intensities, background noise, inter-stimulus intervals, and response window.
- Formula used for percent PPI and whether denominator is subject-level or group-level pulse-alone amplitude.
- Pulse-alone amplitude, baseline movement, no-stimulus trials, and exclusion rules.
- Trial sequence, habituation period, inter-trial interval, and randomization scheme.
- Hearing screen, chamber calibration, sensor type, and amplitude units.
- Whether PPI is reported by intensity, by interval, or as an averaged summary.
References
Evidence notes
Endpoint pages should cite the method literature behind the scored value and keep high-specificity protocol claims qualified unless the source supports them.
- Geyer MA, Dulawa SC. The behavioral assessment of sensorimotor processes in the mouse: acoustic startle, sensory gating, locomotor activity, rotarod, and beam walking. NCBI Bookshelf.
- Swerdlow NR, Caine SB, Braff DL, Geyer MA. The neural substrates of sensorimotor gating of the startle reflex: a review of recent findings and their implications. J Psychopharmacol. 1992. doi:10.1177/026988119200600210.
- Plappert CF, Rodenbucher AM, Pilz PKD. Factors governing prepulse inhibition and prepulse facilitation of the acoustic startle response in mice. Behav Brain Res. 2004.
Related workflow paths
Endpoint articles link to adjacent products, software workflows, and sibling endpoints where the connection is useful and already routable.
Prepulse inhibition calculator
Compute percent PPI from pulse-alone and prepulse-plus-pulse trials.
Acoustic startle endpoint
Check startle amplitude before interpreting PPI as sensorimotor gating.
ConductVision prepulse inhibition
Software workflow for startle gating, intensity curves, and habituation exports.
