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Updated: Aug 24, 2026
Habituation and Prepulse Inhibition of Acoustic Startle in Rodents
Published on: September 1, 2011
Weak prepulses inhibit but do not elicit startle in rats and humans
Neal R Swerdlow1, Jo Talledo, Jody M Shoemaker
1Department of Psychiatry, University of California, San Diego School of Medicine, La Jolla 92093-0804, California, USA.
Background:
Inhibition of startle by weak prestimuli is called prepulse inhibition (PPI). It has recently been reported that 10- to 20-dB prepulses trigger eye-blink motor activity and PPI in normal human subjects. Motor activity after prepulses correlated negatively with PPI in four of nine possible conditions. We now report the relationship between prepulse-elicited startle (PPES) and PPI using weak prepulses.
Methods:
We assessed PPI and PPES using 1- to 5-dB prepulses in humans and in rats after treatment with vehicle or apomorphine.
Results:
Prepulses inhibited startle in an intensity-dependent fashion but elicited no startle activity in humans or rats. Apomorphine eliminated PPI in rats and produced a well-documented increase in stimulus-independent motor activity but did not stimulate PPES.
Conclusions:
In humans and rats, PPES is not a necessary condition for either the elicitation or the disruption of PPI.
