Lily He

Lily HeMarder Laboratory
Department of Biology
Brandeis University

How Does a Crustacean Neuronal Circuit Respond to Changes in Extracellular [K+]? (Part II)

Poster Abstract

Over the lifetime of a crab, the pyloric neuronal circuit faithfully maintains rhythmic motor output, despite various environmental disturbances. In this study, we investigated short-term and long-term responses to superfusions of saline with elevated potassium ion concentrations (2x) across animals. In the initial set of experiments, we superfused modified saline for 10 minutes at a time, and, in some animals, saw the pyloric circuit lose rhythmic activity and recover activity comparable to baseline during the washout. We extended this to longer superfusions of other elevated concentrations (1.5x, 2.5x, 3x) and saw the pyloric circuit partially or fully recover activity similar to the baseline condition within the hour or hour-and-a-half-long manipulation. These responses are indicative of (a) homeostatic mechanism(s) that allows the circuit to re-achieve a particular activity level despite altered environmental conditions. We also have preliminary data on the responses of the PD and LP cells from intracellular recordings that show the changes in the resting membrane potential of the PD cell, as well as changes in calcium envelopes and spike height.

Personal Statement

Fortunately, I have been working in the Marder Lab for almost two years now, and I’ve learned how to critically think about experiments, data analysis and experiment preparation, among many more things. Over this period, I have come to cherish the time I spent over the summer doing research, as it is the only time of the year that I can fully dedicate to experiments and immerse myself in my work. As a result, I have made significant forward progress in my intellectual development and scientific techniques, and invested a large portion of time investigating questions that have important implications for work in related fields and in medicine. Being a Bauer Fellow allowed me the opportunity to continue my laboratory research this summer.

Unfortunately this summer, I ran into far more barriers than expected. I began trying out new and more difficult techniques, but soon ran into difficulties associated with the myriad of electrical equipment. One day, my electrodes would be working perfectly, and the next, that same electrode would be inaccurate in its measurements, due to some small mechanical shift. My experiments became extremely time-intensive and, compounded with the daily technical difficulties, I found myself working late into the evening, sometimes even needing to carry into the next day. However, in experiencing these challenges, I learned to think on my feet more often and improved my ability to troubleshoot problems. I was also able to notice small differences in my setup that had led to those challenging issues. In a sense, I have come to see experimental setup as an experiment in itself. I appreciate the unexpected benefits of troubleshooting, the development of creative problem-solving strategies and greater patience with myself.