Effects of Nicotine Administration and Stress on Sensory-Gating Depend on Rat Strain and Sex

摘要

The present experiments investigated the effects of nicotine administration, nicotine cessation, and stress (environmental and physical) on the acoustic startle reflex (ASR) and pre-pulse inhibition (PPI) of the ASR (measures of sensory-gating) in males and females of two rat strains. Experiment 1 examined the effects of nicotine on 192 Long-Evans rats (a non- albino strain) in individual or crowded housing. For males, nicotine increased ASR and PPI in the crowded condition, but decreased these responses in the individually housed condition. For females, nicotine reduced ASR and PPI regardless of housing condition. Experiment 2 examined the effects of nicotine (0, 6, or 12 mg/kg/day) and immobilization (IM) stress on ASR and PPI of male and female Long-Evans and Sprague-Dawley (albino) rats (N=240). Nicotine decreased ASR and PPI responses of Long-Evans subjects. Nicotine enhanced Sprague-Dawley subjects' responses. Stress increased responses of Sprague- Dawley males and Long-Evans females but decreased responses of Sprague-Dawley females and Long-Evans males.