To test the long term effect of perinatal (pregnancy and lactation) bisphenol-A (BPA) exposure on hippocampal ACh release and behavioral response, and to verify possible involvement of estrogen modulation in adulthood, male rats born from BPA or OIL (vehicle) treated mother, were implanted in the dorsal hippocampus and in the lateral ventricles to allow microdialysis and icv injections. The 2 days before testing rats were primed with estradiol (E) or saline (SAL1) icv injected, then the day of testing were further divided in those receiving ICI182,780 (ER antagonist), b-funaltrexamine (m opioid antagonist) or saline (SAL2).

All animals were exposed to the formalin test (60 min) after a stabilization period (40 min).

Results; Data showed higher basal hippocampal ACh levels in BPA rats than in OIL treated one. Estradiol treatment before testing induced a significant decrement in Ach release in all groups.

BPA as well as the other estrogen-related compounds affected pain differently depending on time of exposure (perinatal, pre-treatment, treatment) and behavioral response (licking, paw jerk).

Conclusion; These data indicate a significant long term effect of estrogenic-like exposure able to change neuronal processes involved in cognitive functions and pain modulation.