This summer, I explored the neural pathways governing itch and pain processing in Dr. Wenqin Luo’s lab. Chronic pain and chronic itch are common disorders that substantially impair quality of life. While we now know that pain- and itch-sensitive primary neurons are divergent populations with different molecular profiles, how these two sensations are differently processed in the brain remains unclear. My project focused on a small region of the brain called the lateral habenula, important in aversive responses to unpleasant events. This part of the brain is activated by both pain and itch stimuli; our goal was to determine whether these activated neurons are segregated or overlapping populations.
To investigate this question, we required a technique that would accurately label activated neurons in the lateral habenula, with the aim of marking brain activation induced by two different stimuli in the same animal. We used a transgenic mouse line called TRAP2 that endogenously expresses a fluorescent protein in activated neurons following a stimulus, as well as virus injections into the lateral habenula that locally label activated neurons. While the viral transduction and antibody staining were successful, we did not yet reach the level of precision of labeling that we are looking for and will continue troubleshooting our experimental methods.
Through this process, I learned essential laboratory techniques like brain sectioning, immunohistochemistry, PCR and gel electrophoresis. I built on previously acquired skills in confocal microscopy and image analysis. I also gained a better understanding of what mouse model-based research looks like, and the overall breadth of neuroscience research. I could not have grown so much from this experience without my wonderful mentor, Suna Cranfill, who was always happy to explain a protocol in greater detail and answer my myriad questions.