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

Rationale: A recent report described sex differences in the effects of nico tine use and withdrawal on prepulse inhibition of acoustic startle (PPI), b ut no sex differences in PPI in non-smokers. Objective: To determine whethe r previously reported male>female acoustic PPI reflect sex differences in s moking 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 wa s 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-smo king normal controls.