Sara Al Yasin ‘21, Emiliano Herrera-Rosa ‘23, and Lisa Y. Maeng
Department of Psychology and Neuroscience, Wheaton College, Norton, MA
We started working with Professor Maeng in Fall 2020 and immediately began learning a range of neuroscience research techniques. We learned how to collect brain tissue slices on the cryostat, carry out histological methods, conduct various behavioral tests, and perform data analysis. Given that women are twice as likely as men to develop stress-related disorders such as depression and post-traumatic stress disorder, we decided to design an experiment that would allow us to gain a better understanding of how stress can alter these behaviors and the brain mechanisms underlying them. Our research project was initially conceptualized as an investigation of the effects of stress exposure on reward-related behavior in female rats, but it later progressed to become a pilot study examining stress effects in both males and females.
We focused our investigation on one signature symptom of depression, which is anhedonia, or the loss of pleasure. In animal models of anhedonia, chronic stress produces reductions in an animal’s consumption of sucrose, a substance it naturally finds pleasurable and typically has a strong preference for. In this pilot study, we were primarily interested in the effects of stress and sex hormones (estrogen and progesterone) on sucrose preference in female rats. Our objective in characterizing the specific effects of stress and sex hormones on behavior in female rats is to increase our understanding of the circuits involved and subsequently, contribute to the development of more targeted treatments for stress-related mental illnesses that are more prevalent in women.
The next steps include further analyzing the underlying pathways that may be involved in the observed effects. One limitation we faced was having to reduce our animal numbers and perform this study with a smaller than anticipated sample size. Despite the limitations due to conducting this research during the COVID-19 pandemic, it pushed us to think creatively and adapt to unexpected changes, limitations, and restrictions that were often out of our control. Most importantly, it was a valuable and fun learning experience for us!