Prenatal Nicotine Exposure and the 5HTα -7 Receptor

Abstract

Prenatal nicotine exposure is a know risk factor for Sudden Infant Death Syndrome (SIDS). This risk increase is thought to be the result of developmental nicotine exposure (DNE) affecting the development of the brains control of breathing. This experiment was executed to determine what affect, if any, this type of nicotine exposure would have on the serotonin (5HT) system, specifically the 5HT alpha-7 receptor. Prenatal rat pups were exposed to nicotine using osmotic mini-pumps during pregnancy, with continued exposure through breast milk after birth (DNE). Brainstem-spinal cord preparations from 1-5 day old pups, both DNE and an unexposed control group, were placed into a split-bath and drugs where administered to either the brainstem or the spinal cord. The frequency and amplitude of action potential burst were measured in the brainstem (rostral) experiments and tonic activity was measured in the spinal cord (caudal) experiments. Both experiments followed the same drug application protocol. A baseline of ten minutes was established, followed by fifteen minutes of 5HTα-7 antagonist application, followed by thirty minutes of 5HTα-7 antagonist + 5HT application, followed by washout for twenty minutes. DNE exposure had statistically significant affects in the rostral experiments, but produced non-significant trends in the caudal experiments.