Behavioral Effects of Pre-Natal Opioid Exposure in Mice

Abstract

By Ally Hassler, Neuroscience; Brittany Smith, University of Cincinnati; Teresa Reyes, University of Cincinnati

Advisor: Brittany Smith

Abstract: Over the past couple years, the number of pregnant opioid users have increased dramatically. If a mother is taking opioids while she is pregnant, it can cause cognitive and developmental effects to the exposed child (Fodor et al. 2014) and neonatal abstinence syndrome (NAS). In this study we used a mouse model to investigate the cognitive effects of morphine and buprenorphine exposure in utero through behavioral tests that evaluate learning and memory, along with risk assessment and novelty seeking behaviors. Our overall hypothesis is that morphine and buprenorphine treatment during pregnancy will cause long term cognitive effects in the offspring. We bred male DBA mice with female C57BL6 mice to study the hybrid offspring. The dams were injected daily with a dose of saline, morphine, or buprenorphine until the pups were weaned. The tests completed included pup retrieval, withdrawal, open field test, novel object recognition test, social interaction test and operant conditioning. We found that (i) in the open field test, the males would spend significantly more time in the center of the arena, (ii) in the novel object recognition test the males exposed to either of the opioids and the females exposed to morphine spent significantly more time with the novel object, and (iii) the male group exposed to morphine was significantly more social than the other groups. These results suggest that the mice exposed to an opioid in utero may be more novelty seeking in comparison to the control saline group.