Does fast-acting antidepressant action of ketamine reverse psychosocial stress-induced hippocampal-dependent cognitive deficits

Harley Haas




Project Summary

This summer I worked with Dr. Sanghee Yun in the Eisch Lab. This neuroscience lab primarily focuses on the dentate gyrus, a part of the hippocampus that involves mood, memory, and reward processing. I specifically looked at whether psychosocial stress decreases pattern separation (ability to differentiate similar stimuli to different outputs) and cognitive flexibility (ability to correctly respond to changes in the environment) in mice, and whether fast-acting ketamine antidepressants can reverse stress-induced cognitive deficits.

The touch screen operant chamber allows for the investigation of hippocampal-dependent pattern separation and cognitive flexibility in rodents. I learned animal care, specifically injections, and helped run the cognition experiment. To implement a user-friendly interface that allows for easy analysis of touch screen data, I worked with other undergraduates and our mentor to create a Python code. Through this research, I also learned about different paradigms for stress-inducing rodent behavioral experiments and performed chronic social defeat stress on rodents. Furthermore, after learning wet lab techniques I was able to explore genotyping further, alongside how to prepare animals for a molecular based experiment.

The Eisch Lab is a combination of several projects, so I was continuously learning new techniques and concepts related to the dentate gyrus. This summer I learned how to do brain sectioning using a microtome to help with tissue collection. Additionally, I was taught how to mount sections and perform staining with immunohistochemistry. Interestingly, I was able to learn how to do brain surgery on rodents using stereotaxic coordinates to prepare them for an optogenetics study.

As a prospective major in neuroscience, this experience was extremely beneficial to me as I got to explore both the behavioral and molecular parts of neuroscience research. The mentorship aspect of the Eisch Lab was also a primary factor in my choosing this summer experience, since I was able to explore several types of neuroscience research and ask questions about a career in neuroscience research. I feel that this experience strengthened my understanding of neurological and biological concepts from inside the classroom and allowed me to gain invaluable hands-on experience.

To see my poster, visit Penn Presents: