B13: Effects of Morphine Withdrawal on FMOR Mice

Due to problems caused by the opioid crisis in the United States, it is necessary to find solutions for both prevention and treatment of opioid abuse. This study looks at manipulation of the FoxP2 gene in regards to changes in withdrawal symptoms with the opiate morphine. This was done by removing the mu-opioid receptors from neurons that expressed the FoxP2 gene in C57BL/6J mice. It was hypothesized that mice without the mu-opioid receptors (FMOR mice) would have fewer withdrawal symptoms than the wild-type mice (WT) with the receptors. Withdrawal symptoms were assessed with conditioned place aversion (CPA). Each mouse was assigned a side of a CPA chamber with the assumption that, after going through withdrawal on that side, the mouse would then show a greater aversion when allowed access to the whole chamber. Locomotion was also examined.

It was found that there was significance in session (baseline time compared to posttest time), showing that conditioned place aversion was achieved. However, the data was not significant for genotype or interaction effects, so the FoxP2 gene likely does not affect the withdrawal symptoms one can experience. For locomotion, no significant differences were found between genotype or session nor any interaction effects. In contrast, when looking at baseline locomotion, significance was found for both sex and interaction effects but not for genotype. The female FMOR mice showed the longest distance, both wild-type sexes in the middle, and male FMOR mice with the shortest distance. However, caution must be held when examining the results as this experiment was run with an underpowered sample size for the sexes. It is possible an increased sample size with special consideration to sex differences would show different results. Overall, removing the mu-opioid receptors from neurons with the FoxP2 gene is not enough to alter opiate withdrawal in mice.

Author(s): Megan Robertson, Zoology and Premedical Studies Major

Natella Parsadanyan, Biology and Neuroscience Major

Mallory Miller, Psychology and Neuroscience Major

Advisor(s): Anna Radke, Department of Psychology