Fig. 7.

Prepulse inhibition of the acoustic startle response in wild-type (n = 22) and R6/2 transgenic (n = 9) mice. Symbols indicate mean ± SEM of the response of the two groups at different ages to white noise stimuli of 120 dB (A–E) and 105 dB (F–J) with either the baseline startle response recorded to the primary acoustic startle stimulus alone (A, F, respectively) or with 100 msec prepulse warning stimuli of rising intensities (2, 4, 8, and 16 in B–Eand G–J, respectively). R6/2 transgenic mice exhibit impaired PPI by 8–9 weeks of age, and this impairment progressively declines with age. Asterisks indicate significant differences in performance between the two genotypes (*p < 0.05, **p < 0.01).