For my PhD dissertation, I examined how the circuitry of the central nervous system changed when the caterpillar of the tobacco hornworm, Manduca sexta, undergoes the metamorphic transformation to a moth. In the process, I identified a collection of pre-motor interneurons based on their unique forms and patterns of electrical activity, and examined how they changed during metamorphosis. During this work, I identified an unusual pattern of electrical activity in neurons that appeared to be specific to the pupal stage.
Later, I studied the influence of learning-related genes on the structure and function of the synapse in fruitfly, Drosophila melanogaster. The neuromuscular synapse, which mediates communication between the nervous system and muscle in the larval Drosophila, has served as a powerful model for the discovery of genes important for stability and plasticity (the ability to change) of synapses in general. Our work demonstrated important roles for genes such as ADF1 and AP-1 in regulating the physical size and electrical strength of synapses.
As a staff scientist at NIH, I studied the ways in which volatile anesthetics (the ones you breathe) alter the excitability of neurons (nerve cells), and the synaptic communication between them. Again using the larval Drosophila synapse, I found that volatile anesthetics such as isoflurane (an ether modified by adding chlorine and fluorine atoms) reduce the excitability of neurons, and thereby reduce the strength of synaptic communication. Further, we explored the role of an ion channel that releases calcium from storage inside the cell, the Ryanodine Receptor (RyR) in mediating the anesthetic effects of another volatile anesthetic, halothane. I used both patch-clamp electrophysiology and direct imaging of calcium inside cells to show that halothane causes the RyR to open and release calcium, while at the same time the electrical potential across neurons’ membranes becomes more negative, making the cells less able to be excited.
In 2013, I decided to refocus my efforts from research to teaching. I became a lecturer at the University of Maryland, College Park, teaching at the Universities at Shady Grove Campus. I teach Mammalian Physiology, Principles of Neuroscience, Cell Biology Laboratory, and Neurobiology Laboratory to students in the Biological Sciences program. My role as a teacher has motivated me to begin the Elysia project, as a way of introducing students to the ecology, behavior and neurobiology of these unique creatures.