Katelyn Tu stands in front of the Monell building with colleagues

CCPA Summer Series 2022: Monell Chemical Senses Center

By Katelyn Tu ’23

Funding Source: Gertrude Albert Heller Memorial Grant

This summer, I worked at Monell Chemical Senses Center as a student research assistant. Monell Chemical Senses Center is a non-profit research institution that particularly focuses on taste, smell, and chemesthesis. I helped my mentor, Dr. Wang, with her project on Parkinson’s disease (PD).

We are still at a very preliminary stage of the project, but our goal is to identify Parkinson’s disease biomarkers and its associated genes in the olfactory tissues. People who are diagnosed with Parkinson’s disease oftentimes struggle with loss of smell in the very early stages. Because of this particular symptom, our research aims to find out if genes associated with Parkinson’s disease genes are preferentially expressed in the olfactory tissues—tissues that are involved in our sense of smell—compared to other tissues in our body. In order to test whether PD genes are expressed more in the olfactory tissues than other tissues in the body, we first spent the first two weeks conducting online research to find a total of 30 genes that are known to be associated or cause Parkinson’s disease based on published articles and data. Then for the next four weeks, we conducted a wet lab.

A typical week in a wet lab consisted of tissue extraction, RNA extraction, running PCRs, and then dry lab analysis. Perhaps the most intimidating part of the whole internship was tissue extraction, a procedure that required euthanizing lab mice and extracting brain tissues of interest. I remember seeing three tiny cute mice cuddling together in the cage. I wanted to hold them, but reminded myself right away that they are lab animals, and I should not get attached. Dr. Kuboki showed me how to sacrifice the mice by putting them on dry ice to release carbon dioxide gas as a common method of euthanization. It did not take more than 30 seconds before the mice fell over unconsciously. After shadowing this procedure, it became clear that research with experimental live animals is not for me. While I understand the importance of using animal models for research, watching many mice get sacrificed over the span of weeks has made me ponder the ethics of animal research.

Although overall, I’ve built many fun and memorable experiences during this internship, there were also frustrating moments that slowed down our research. For instance, for two weeks straight, my mentor and I were struggling to find out a lab error that resulted in our polymerase chain reaction (PCR) genes not amplifying. Simply put, PCR is a common laboratory technique used to amplify a particular segment of DNA of interest. The struggle to find the mistake during the procedures that resulted in PCR failure made me doubt every step I performed. I remember triple-checking all the calculations and instructions, but still, the PCR would not amplify. Then, Dr. Hong tried demonstrating each step carefully for me, as I took notes carefully next to her. The only factor that I noticed that she performed differently was that she used a different brand of water. After several more trial and errors, we finally found out that the water that I used happened to be contaminated. Additionally, I caught COVID and another respiratory infection right after finding out this error, which required me to take two weeks off. This experience definitely taught me that research is time consuming, and at times may be discouraging due to uncontrollable setbacks. However, the demoralizing parts of research makes me appreciate the intellectual stimulation it provides. Perhaps the most rewarding feeling comes from when that “light bulb” moment hits, and I suddenly understand something that has previously confused me. Although research can take months or even years to witness a breakthrough in an experiment, the moments of sheer intellectual joy during the process are rare and well worth it.

At the end of the summer internship, our project found out that some, but not all, PD-associated genes are highly and preferentially expressed in the olfactory bulb and epithelium. These genes may serve as potential olfactory biomarkers for early detection of PD. As mentioned earlier though, we are at the very preliminary stage of this project, and we plan to further our research for the next year using mice that have been genetically modified to have Parkinson’s disease and even using human models to hopefully identify the potential signs that best predict Parkinson’s disease onset and/or progression. I look forward to continuing this research during the school year, and I thank the Gertrude Albert Heller Family for funding this enjoyable learning experience.