Janet Song, Chemical and Physical Biology Concentrator in Quincy House, Class of 2013

This summer (as with the past 2 summers and 2 school years), I’m working in the Macklis lab in the Department of Stem Cell and Regenerative Biology (SCRB) thanks to funding from the Harvard College Research Program. I’m a rising senior concentrating in Chemical and Physical Biology, who loves watching football, playing cards, and eating froyo.

An aerial view of the SCRB department

I study corticospinal motor neurons (CSMN), which are the neurons that control voluntary movement – like moving your arms or legs. CSMN are located in the neocortex (the “cerebral cortex”; that’s the part of the brain that makes us human) and extend axons through the brain and down the spinal cord to make connections at every level of the brainstem and spinal cord, from the controlling centers for the face in the brainstem to the cervical spinal cord located at our neck, down to the lumbar cord located at our lower back. I am interested in characterizing genes that are specifically expressed either in the population of CSMN that extend axons to the cervical spinal cord or those that extend axons to the lumbar spinal cord to see what roles they play in axon outgrowth and building the “circuitry” during development. As you can probably imagine, understanding the development of CSMN is important for spinal cord injury (in which CSMN damage leads to paralysis) and diseases such as amyotrophic lateral sclerosis, or Lou Gehrig’s disease (in which CSMN are the brain neurons that degenerate and die, leading to paralysis).

Green shows the path that CSMN that project to the cervical cord would follow, while red shows the path that CSMN that project to the lumbar cord would follow

The Macklis lab uses mice to study CSMN development. One of the ways we investigate how genes function during development is by doing experiments using in utero electroporation. As the name suggests, this allows us to mis-express or knock-down the gene we’re studying in specific progenitor cells and neurons. We then analyze the developing mice a few days after that. Single genes each do specific things, like individual concert instruments, and, together, orchestrate the incredibly complex developmental processes that build the brain!

Of course, I wasn’t born with a pipette in one hand and a test tube in another. When I first joined the Macklis lab way back in freshman year, the only things I knew about neurons were that some of them were located in the brain and that they allowed us to form conscious thoughts. My Principal Instructor, Professor Jeffrey Macklis, paired me up with postdoctoral fellow Vibhu Sahni, who has been an amazing mentor through the years. Both Prof. Macklis and Vibhu have been instrumental in helping me to grow as a scientist.

Lab isn’t always fun though. I can’t tell you how many times I’ve repeated the same experiment over and over again because it failed the first time (and the second time and the third time …), and the hours are nothing to sneeze at. Mice aren’t thinking about what day of the week is convenient for you when they become pregnant or give birth. And I, along with most of my fellow undergraduates, spend time in lab on the weekends as well.

At the end of the day, though, I’m here doing research because I genuinely enjoy it. There’s a special kind of excitement that comes when you discover something that no one else in the world knows, and it’s that sense of possibility – combined with a pervasive curiosity about biological systems – that keeps me motivated. As I apply to graduate programs in biology this coming fall, I hope that I will continue to possess a sense of wonderment and inquisitiveness about the natural world.