Reduction in prepulse inhibition following acute stress in male and female wistar rats

Abstract

Prepulse inhibition (PPI) of the startle response is widely recognized as an operational index of sensorimotor gating. While its use in psychopharmacological studies has increased, it is essential to examine how different modulatory factors, such as emotional variables highlighted in human studies, influence PPI. To this end, this study aimed to assess the impact of acute stress on PPI and the startle response. We hypothesized that acute stress would reduce PPI and increase the startle response, potentially in a sex-dependent manner. To test this, male and female Wistar rats (n = 48) were exposed to acute stress via either forced swim test or inescapable footshocks treatment, with an untreated group serving as control. Immediately after stress exposure, PPI and the acoustic startle response were measured. Results revealed a significant reduction in PPI following both stressors, with no sex differences, suggesting that acute stress impairs sensorimotor gating regardless of sex. The startle response was reduced, again regardless of sex, in those animals subjected to the forced swim test as compared to those that received inescapable shock and those in the control group. These results may contribute to a deeper understanding of stress-induced alterations in sensorimotor gating and suggest a potential value for PPI as a translational measure in stress-related neuropsychiatric research. However, given the limitations of our current findings, further research is necessary to fully elucidate the specific mechanisms and the extent of PPI's translational utility in this context.