Stressed Rats and a Stressed Undergraduate

Chronic stress leads to a greater likelihood of the development of many conditions including post-traumatic stress disorder (PTSD), anxiety, irritable bowel syndrome (IBS), functional dyspepsia and other gastrointestinal (GI) dysfunction. This indicates a likely rearrangement of neural pathways and regulation, although the mechanisms of how this happens are not yet known. As an APS Undergraduate Summer Research Fellow, I worked for ten weeks under my research mentor Dr. R. Alberto Travagli studying the neurochemical oxytocin’s role in stress adaptation. My project focused on the regulation of oxytocin signals between the brain and GI tract under conditions of chronic stress in rats. In other words, I studied whether oxytocin has a different effect on the brain and gut of rats after they have been stressed.

Following a 5-day stress treatment on each rat, oxytocin was microinjected in the dorsal vagal complex (i.e. the brain area that directly signals the GI tract). The response to these injections on gastric tone and motility in two areas of the stomach were then recorded and analyzed. The research is still ongoing, but we hope to answer a few questions: How does the regulation of oxytocin change after stress adaptation? Does oxytocin work through different neural pathways after homotypic stress (i.e. same stress each day) or heterotypic stress (i.e. different stress each day)? Since females have a greater likelihood of developing GI disorders, do sex/estrogen levels affect the regulation of oxytocin under stress? Although we are still collecting data, I am very excited to see the results when completed and honored to participate in this research!

What surprised you most about working in the lab?

Upon starting this project, I was surprised by how much skill is required to complete the tasks at hand. Although the technology we use to inject oxytocin and record the gastric response is quite advanced, it can easily be faulted by a human mistake. For example, if I did not suture the sensors tight enough to the stomach, the responses were difficult to read and interpret. There was a huge learning curve to carrying out the research day-to-day and then it was another challenge to ensure I was as consistent as possible between animals. Additionally, I was surprised by how much my project changed between the beginning and end of the summer. For example, early on we injected a new pathway-blocker out of curiosity, expecting it to have little to no effect on oxytocin injections. Surprisingly, however, in one treatment group it seems to be blocking the effects of oxytocin. After, we used that pathway-blocker for every animal and its effects may be crucial to our final conclusions.

I am very grateful to the American Physiological Society for providing me this opportunity because it has made me realize how challenging a career as a basic research scientist is! This summer has exposed me to how exhausting, long, and physically demanding lab research can be. But, I love the big-picture parts of research; designing the experiments, analyzing the results, and adjusting when results are not as predicted. It is amazing to work on research that could be part of a bigger solution (i.e. understanding of anxiety/IBS/colonic pain), especially when you can collaborate with other researchers and pool data to come to even more conclusions within each study. However, I will admit that lab research is grueling work and, like the rats, I was a little stressed at times! I look forward to next year’s summer project so that I can experience translational or clinical research and gain a more holistic view of the research world.

Julia Zimmerman is a sophomore majoring in Neuroscience at Swarthmore College in Swarthmore, PA. She is a 2017 Undergraduate Summer Research Fellow (UGSRF) working in Dr. R. Alberto Travagli’s lab at Pennsylvania State University College of Medicine in Hershey, PA, funded by the APS. After graduation, Julia intends to pursue work as an MD-MPH, or MD-PhD, bridging basic research into the clinical world.

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