The long-term effects of neonatal pain and drug exposure on male and female mice

Abstract

This study examined the lasting effects of neonatal drug and pain exposure in male and female mice. On their day of birth mice were given a surgery and injected with either morphine or saline. Pain controls received no surgery but still received the saline or morphine injection. In adulthood, the mice were tested for pain behavior with the hot plate, tail flick, and abdominal writhing tests. The different tests draw from the different pain systems of the body. Morphine and pain exposure showed long-term effects depending on which test was analyzed. These differences were for the most part, the same for male and female mice. Neonatal pain tends to decrease in sensitivity in adulthood particularly in males, but morphine was found to block this effect.