Figure 4. Expected results of a typical PPI experiment.

A. Software output of a 100 millisecond response window after the presentation of a pulse-alone and a prepulse-pulse trial. The arrows indicate the maximal response peak amplitude, which is used to determine the acoustic startle response and the maximal response time as an index of the animal’s reactivity to the stimuli. B. Reactivity on prepulse-pulse trials (PPiS) relative to pulse-alone/startle trials (S) is utilized to evaluate prepulse inhibition (PPI). C. Percent prepulse inhibition (%PPI) is shown for naïve wild-type mice with a BL6N background produced in our institute. As expected, PPI levels increase with increasing prepulse intensity (above background), and variability is low.