Student Spotlight on John Walsh
Fall 2010
The Undergraduate Research and Creative Activities Awards (URCAA) program at Florida State University (FSU) awards students $4,000 to conduct a summer research project or creative activity under the direction of a faculty mentor. Students who are granted these awards enhance their undergraduate experience by taking on directed research and creative activity under the supervision and mentorship of some of Florida State University's most esteemed faculty. John Walsh, a senior pursuing a BS degree in Chemical Engineering with a major in biomedical engineering, was the recipient of a URCAA award. He has been working on magnetic resonance imaging research with Dr. Sam Grant for the past two years. John will graduate in spring, 2010, after which he will attend graduate school to further his study of biomedical engineering. John presented his research work entitled "Single Cell Analysis of Osmosis" at the Undergraduate Research and Creative Activity Award Symposium, held September 29, 2009, at the FSU College of Medicine.
Abstract:"Single Cell Analysis of Osmosis"
Vital to the maintenance of cell homeostasis is a delicate balance of water and sodium in the intracellular and extracellular environment of every living cell. Osmosis, defined as the passive diffusion of water to regions of higher solute concentration, is driven by imbalances between cells and their environment, which becomes critical in excitable cells such as neurons and myofibers. Using the L7 motor neuron from the sea slug Apylsia Californica, a known model organism for neuronal studies, the effect of osmosis on sodium distributions and cell swelling can be determined in this prototypical neuron. High field magnetic resonance imaging (MRI) using the 21.1 T, 900 MHz ultra-wide bore magnet at the National High Magnetic Field Laboratory (NHMFL) is performed to quantify intracellular sodium distributions. So far, the focus of this project has been on the construction of the solenoidal microcoil used in the MRI experiments and the perfusion chamber necessary to maintain control over the extracellular environment. The microcoil tuned to the resonant frequencies of both 1H and 23Na, 900 MHz and 268 MHz, respectively, is used to perform MRI analysis on the isolated neurons. Through osmotic and toxic alterations of the extracellular environment, the effect of osmosis on intracellular sodium concentrations is measured.
