Dr. Kara Marshall
Assistant Professor Baylor College of Medicine
Postdoctoral Fellow Scripps Research, La Jolla
PhD in Neurobiology and Behavior Columbia University
MS in Neuroscience Baylor College of Medicine
When Dr. Kara Marshall first joined a neuroscience lab as an undergraduate, she was tasked with the rather unglamourous job of “expressing” – or manually helping to empty – the bladders of rats recovering from spinal cord injuries. Years later, Kara’s career came full circle in a fantastic way: during her postdoctoral fellowship, she discovered the cellular mechanisms underlying the sensation of bladder stretch and urination. However, it was mostly a coincidence that her scientific training began and ended with the bladder. Kara has been driven throughout her career by a much broader fascination in the peripheral nervous system, a topic often relegated to the periphery of most neuroscientists’ minds. But Kara has thrived in this niche. She is now setting out to start her own lab at Baylor College of Medicine, excited to dive into questions of how the body and brain perceive and respond to internal sensation.
Kara inherited an interest in biology from her mother. When Kara was young, her mom was taking night classes to complete her bachelor’s degree and was majoring in biology. Kara loved to help her mom study, even when that meant memorizing all of the amino acid structures. "I tell her she made me into the nerd I am today," Kara says with a laugh. In college, Kara joined a neuroscience lab, drawn to the brain because of its control over so many aspects of physiology. She studied pain after spinal cord injury and how peripheral inputs affect motor recovery. This experience was formative in that it filled Kara with an intense interest in the peripheral nervous system, a curiosity that has driven her research ever since.
After graduating, Kara began a PhD in neuroscience at Baylor College of Medicine and joined Dr. Ellen Lumpkin’s lab, which focuses on touch perception. During her third year of graduate school, Kara was faced with a difficult decision. Ellen was moving the lab to Columbia University, and Kara had to decide whether to join Ellen in New York or switch labs. She ultimately made the decision to go to New York, but it was more disruptive to her trajectory than she imagined it would be. At Columbia, Kara started working on a whole new project and had to start over in other ways as well, including re-taking her qualifying exams. But eventually Kara hit her stride. She discovered that the touch receptor neurons that innervate skin cells essentially degenerate and regrow every time the skin renews itself. This work elucidated the remarkable plasticity in the neuronal-epithelial complex responsible for sense of touch. In a completely different project, Kara also studied how the nervous system innervates the bat wing, discovering sensory neurons in a position to report air flow and touch. While much of her graduate work might be considered “descriptive”, Kara rightly argues that descriptive work does not deserve the negative connotation sometimes attached to it. “No one says, ‘Ugh, Ramón y Cajal’s work was so descriptive.’” Descriptive work holds exceptional value, and it is only once a phenomenon has been described that its underlying mechanisms of action can be uncovered.
Ultimately, Kara did a full-length PhD at Columbia after her years at Baylor. She jokes that she likes to think of her time at Baylor as a tech position so that her PhD doesn’t seem quite so long. But in reality, Kara recognizes the ways in which she grew as a person and scientist throughout her long stint in graduate school. She believes it prepared her for her postdoc in ways that a typical PhD would not have. Additionally, she gained two networks of colleagues – in Texas and in New York – in a period when most trainees develop just one. Her network at Baylor became especially important when she was on the job market, and she is thrilled to be joining a community with which she has strong ties from her early graduate school years. So while the move stands out as a difficult challenge during her career, it was also rich with opportunity.
After her PhD, Kara began a postdoc with Dr. Ardem Patapoutian at Scripps Research in La Jolla. In Ardem’s lab, she became entranced by the ways in which the body senses internal forces like blood pressure and stretch. She discovered that PIEZO2, a mechanoreceptor first identified by the Patapoutian lab years earlier, is required for sensation of bladder stretch – the sense that the brain interprets as a need to pee. Kara found that PIEZO2 is expressed in both the urothelial cells of the bladder lining as well as the sensory neurons that innervate it, and these cells work in concert to alert the brain that the bladder is filling. As she begins her own lab, Kara will use this work as a jumping-off point. While her postdoctoral research focused on stretch sensation in the healthy bladder, Kara is also interested in how internal sensation can go awry. She plans to study (among many other things) the mechanisms underlying cystitis, a condition in which bladder filling causes pain. Although she is a basic scientist, Kara finds motivation in connections to human health, particularly in studying how dysfunctional internal body signaling might interrupt important daily processes. Ultimately, she would also like to understand not only how internal sensation works in different organs, but also how the brain then uses that information to govern physiology and behavior.
While she has a strong sense of her broad research goals, Kara thinks the individual project ideas are likely to change throughout the years. Kara does not identify as the type of scientist who picks a question and then pursues the answer relentlessly until it’s clear. Instead, she likes to explore several scientific avenues and then follow the most surprising, engaging data. She envisions her lab as more than the sum of its parts, with its members elevating each other through their feedback and diverse curiosities. Because of this, Kara places a high priority on creating a lab environment in which everyone feels comfortable communicating – bouncing ideas off each other and identifying potential pitfalls before they arise. Under Kara’s guidance, and with her unbridled creativity as inspiration, the Marshall lab will undoubtedly go on to stretch the boundaries of knowledge in the field of interoception.
Find out more about Kara and her lab’s research here.
Check out Nancy’s full interview with Kara on September 17th 2021 below or wherever you get your podcasts!
