Sex differences in sensorimotor gating of the human startle reflex: all smoke?

Rationale: A recent report described sex differences in the effects of nicotine use and withdrawal on prepulse inhibition of acoustic startle (PPI), but no sex differences in PPI in non-smokers.

Objective: To determine whether previously reported male>female acoustic PPI reflect sex differences in smoking effects on PPI, rather than simple sex differences in the regulation of PPI. A retrospective analyses of >600 carefully screened normals tested over the past 12 years was completed.

Results: Male>female acoustic PPI was detected in analyses that included: 1) all subjects; or 2) self-declared non-smokers.

Conclusions: Sex differences in PPI cannot be accounted for by smoking history, because they are present across a large sample of non-smoking normal controls.