50. Using Forced Swim Test to Assess Differences in Learned Helplessness Between Sex and Adolescent Stages

Abstract

Learned helplessness is the feeling of incapability from repeated failures over time. It is one of the factors that causes and exacerbates depression and may cause an individual to stop attempting to escape a bad situation. Examining learned helplessness and what makes an individual more susceptible to it offers insight into why some demographic groups are more likely to develop depression disorders or addiction than others. An assessment widely used to measure learned helplessness is the forced swim test, where a mouse is placed in a container of water over a period of time, which induces stress. Learned helplessness develops during repeated sessions, as the mouse becomes aware it cannot escape the container. In the current study, mice were placed in the containers for five minutes for ten consecutive days while being recorded on video. Videos were coded for elapsed time of mobility, immobility, and latency to first immobility to measure the development of learned helplessness over time. Another construct examined is whether learned helplessness develops differently depending on sex or developmental window during adolescence. Male and female C57Bl6/J mice were separated into groups based early (p22-31) and late adolescence (p42-51) to investigate differences in stress experiences and development of learned helplessness. By utilizing forced swim test, existing knowledge is built upon regarding learned helplessness and interactions with sex and age during these key developmental windows. Future studies will build upon these findings to investigate if adolescent learned helplessness creates adult susceptibility to addiction.

Keywords: Forced Swim Test, Learned Helplessness, Mice, Sexual Dimorphism, Adolescence, Addiction