Eveline Murphy-Wilson '21

Major: Integrative Neuroscience
Bio: Eveline Murphy-Wilson lived in Minneapolis, Minnesota until moving to New York to study Integrative Neuroscience. She has worked in a research lab on campus for three years. After graduation, she is going to pursue a PhD in Developmental Neuroscience.

Title of Research: The role of oxytocin and epigenetic mechanisms in mediating kcc2 expression and synaptic inhibition in zebrafish neurons
Partner: Jessica Caushi
Mentor: Dr. Alma Rodenas-Ruano
Abstract: In the nervous system, balance between excitatory and inhibitory neurons is essential for normal brain function and development. Neurons are initially excitatory, but at a critical period in development, inhibitory synapses become functional. Activation of the gene kcc2 is required for initiating inhibition in neurons. Mechanisms that trigger the transcriptional activation of this gene are unknown. One possibility is that during development, epigenetic mechanisms promote transcription of the kcc2 gene, initiating inhibition. Epigenetic control of transcription is mediated by environmental inputs, indicating that kcc2 might be turned on by an environmental stimulus that changes epigenetic marks associated with the gene. We hypothesize that the activation of kcc2 relies on epigenetic marks that change from a repressive state, where neurons are excitatory, to an activated state, where they become inhibitory. Evidence points to the neurohormone oxytocin as an external factor that initiates kcc2 expression as a result of oxytocin's influence on epigenetic marks. Our goal is to use zebrafish as a model to elucidate the epigenetic map of kcc2 before and after the gene is expressed, and to clarify how oxytocin influences accessibility to the kcc2 gene. We have pinpointed the time at which kcc2 is turned on, found differences in epigenetic methylation marks in the kcc2 gene before and after expression, and tested the impact of exogenous oxytocin on these marks and kcc2 expression. This provides a platform for understanding the mechanisms involved in the acquisition of inhibition, and a way to understand how an aberrant environment can disrupt them.