Author Archives: Alexus Roberts

Impact of Low PD-1 Expression on Chronic Pain-Induced Depression and Anxiety

Programmed Cell Death Protein 1 (PD-1) is primarily recognized for its role in immunomodulation, where it functions as an inhibitory regulator of the immune response. However, recent research has started to examine PD-1’s involvement in neuromodulation. This project explores PD-1’s role within the context of chronic pain-induced anxiety and depression. The chronic pain model was established using a Spared Nerve Injury (SNI) on PD-1 KO and Wild Type (WT) mice, and verified using pain quantification tests. The resulting anxiety and depression were measured using several behavioral tests. The behavioral tests measuring anxiety did not find significant differences between the KO and WT mice at two weeks, which was expected as anxiety-like behaviors often take 6-8 weeks to appear in chronic pain models. We plan on addressing this limitation by performing a long-term version of this study. We did find notable differences in depressive behaviors between the two groups, in which the KO mice displayed lower levels of depression. This suggests that anti-PD-1 treatments may have a protective effect against depression. The preliminary results from this project will provide the basis for a continuation of research, leading to a greater understanding of PD-1’s role in pain-induced anxiety and depression.

The Importance of Water

I found Lali’s talk on her summer project very interesting, not only for the content, but also for the practical applications of her work. Water is an essential aspect of life, for both humans and other animals, and the quality of it has huge implications for everyone. I haven’t studied ecology much at all, but Lali broke her project down into something that was easy to understand by clearly outlining each component of it. While every project presented and discussed was important and had fairly clear benefits, I felt like Lali’s was one of the few that were centered on the Durham-Raleigh area, which made it really interesting to learn about. Her work incorporated ecology, environmental conservation, and social issues into a cohesive whole as it explored the water quality of two streams, one of which leads directly into a drinking water reservoir.

I also really liked that Lali’s project included fieldwork, and I enjoyed its innovative method of using semi-aquatic insects to indirectly measure the impact of urbanization and development on water and soil quality. Overall, I’m very interested in the long-term results of this project, and how its findings will be utilized in further work, whether that work is environmental research or reform. It certainly addresses a very important question and potential local issue.

Mice! All Day, Everyday

Although I have a project plan, every day I go into the lab I have different tasks and responsibilities.  I’ve learned lots of practical skills, like the full process of genotyping, from collecting the tissue to imaging the gels, as well as how to run a variety of behavioral tests.  I start the day by sitting at my desk and reading through the various papers my mentor sends as well as other papers I search up about relevant procedures and protocols, such as the Cre-lox system.  Once my mentor arrives I start on the day’s work, usually reporting back to her periodically throughout the day.   I also attend the weekly lab meeting every Monday, during which each lab mentor presents the progress they made over the last week.

Next Monday, I will be conducting behavioral tests on my own, as well as completing genotyping on several cages of mice.  The behavioral tests are crucial to my project, as we are studying the influence of the PD-1 protein on anxiety and depression, and so we will be spending around two weeks conducting them.  Although the mice we are using in the tests were bred in lab and should be the genotype that they are labeled, my mentor explained the importance of double-checking each aspect of the experiment to catch any mistakes, so I will test the genotype of each mouse.  As I work, I record the protocols I learn into my electronic notebook as well as other data I collect throughout the day.

Acupuncture and Anesthesiology?

Although I’ve been working in Dr. Ji’s lab for over a year, I didn’t know very much about him at all. Although he was incredibly friendly and welcoming, there was a part of me that was fairly intimidated: I was an undergraduate student and he was a highly distinguished PI and professor! I’m not sure when I would have gained the confidence and initiative to have a full conversation with Dr. Ji, but this week’s blog forced me to step up to the challenge. However, once we started talking, it stopped feeling like an impossibly intimidating task and I found myself immensely grateful to have stepped out of my comfort zone.

I knew that Dr. Ru-Rong Ji’s research interests include anesthesiology, pain research, and neurobiology, but I had no idea why he chose those areas. With the specificity of his work, I was incredibly curious about how he ended up studying the things he did, and his answer was surprisingly simple: acupuncture. When he was in college, he became extremely interested in acupuncture and how it relieves pain, which set him on the course that led to his current position as a Distinguished Professor in Anesthesiology and Chief of Pain Research. When I asked him why he chose to go into research and how he got to where he is now, he gave me some advice that has been echoing in my thoughts this past week. He told me that the three most important traits you need to have to go into research are commitment, passion, and curiosity. Looking back at everything he told me about his life, it is easy to see that these three traits have been a recurring theme throughout. I left the interview a little overwhelmed, but extremely excited to really think on what I learned and how it might apply to my plans to become a biomedical research scientist. More than anything though, I am so grateful for the opportunities I have to talk with experienced researchers and to participate in a community focused on curiosity and hard work here at Duke.

Aches and Pains

The lab I’ve been working in has an overarching focus on pain signaling and sensory plasticity, which covers the wide range of interests of all of the lab members. Working in Dr. Ji’s lab has made me appreciate the complexity of pain, from the different types, like chronic vs acute, to the vast amount of biological and molecular pathways involved. The sheer amount of research being done and research that still has to be done is close to overwhelming, but working with my research mentor, Dr. Junli Zhao, has helped me focus in on a specific area that I can contribute to. Dr. Zhao primarily studies the PD-1 gene and its various roles, especially in pain signaling.

My project builds off of previous research conducted by the lab as a whole, and observations made by Dr. Zhao. We are examining the impact of the gene encoding the programmed cell death protein 1, or PD-1, on chronic pain-induced anxiety and depression, as well as cognition. The primary methods we are using are mouse models, in which we will first induce a chronic pain condition using a spared nerve injury, or SNI, then use a wide variety of behavioral tests to measure the anxiety and depression levels in the mice, as well as their pain levels and cognitive abilities. We will also examine the expression of PD-1 in the brain, particularly the amygdala, which has been found to play a role in anxiety and depression. This examination of PD-1 expression will be conducted through the use of immunohistochemistry and RNAscope.

Community and Connection in Research

Although I’ve always been certain that I want to study something in the sciences, I wasn’t always interested in research. I had never met anyone who did scientific research before coming to Duke, so the specifics of what happens in research labs were a bit of a mystery to me. Over time I became more and more curious about what a career working in a lab would actually consist of, and started to look for ways to get involved, which ended up leading me to BSURF! Since arriving at Duke, and even this first week, I’ve been able to strip away some of that mystery as I have met so many people who do research as a career, as well as other students interested in pursuing a career in research.


I’m definitely looking forward to getting some hands-on experience this summer, and hopefully learning some technical skills that I can put to use during my research experience at Duke and in the future. Although I had already worked with my research mentor before this summer, I am really excited to work on a plan that I will be involved in from the very start! Working in Dr. Ru-Rong Ji’s lab has been an amazing experience so far, and I’m thrilled to be able to work there on a daily basis. Beyond the actual research that I’ll be doing, I’m also particularly interested in meeting more researchers and learning more about the various labs at Duke, in order to make connections and really explore the research community as a whole.