The Influence of Imipramine on the Egg-Laying Behavior of Caenorhabditis elegans

Discovering new ways to treat mental disorders is at the forefront of scientific research due to their imposing challenges on worldwide health. A current drug therapy option is imipramine, marketed as Tofranil, a tricyclic antidepressant (TCA) used to treat mental disorders such as depression. TCA’s predominantly inhibit the reuptake of the neurotransmitter, serotonin. The effects of exogenous serotonin increases egg laying by stimulating vulva contractions within Caenorhabditis elegans. To determine the effect of imipramine, C. elegans were analyzed based on their important physiological process, egg laying. Wild-type (N2) C. elegans responded to imipramine by showing increased egg-laying behavior. In order to observe the phenotype of mutant C. elegans in imipramine, worms were treated with ethyl methanesulfonate (EMS) to induce point mutations. The desired recessive mutants (Strain A) were determined by those who laid the least amount of eggs in the liquid egg-laying assays of imipramine. Egg laying assays were also conducted in doxepin, serotonin, and control M9 solutions. Since doxepin is a TCA similar to imipramine, it had similar effects on Strain A mutants by also demonstrating a decrease in egg-laying behavior.