Meet the lab!
Doug McMahon, Ph. D.
Currently Stevenson Professor of Biological Sciences at Vanderbilt, I obtained my BA and PhD in Biology from University of Virginia (1980, 1985), and was awarded the 1987 Donald B. Lindsley Prize in Behavioral Neuroscience from the Society for Neuroscience for my dissertation research in circadian rhythms. From 1986-1990 I was postdoctoral fellow in Neurobiology at the Biological Laboratories at Harvard University, in the laboratory of Prof. John Dowling with whom worked on retinal neuromodulation. I started my own laboratory in the Department of Physiology at the University of Kentucky in 1990, and in 2002 moved to the department of Biological Sciences at Vanderbilt. Thanks to the many terrific lab team members the laboratory has been continuously funded by the NIH for 33 years and we have authored 105 publications.
Sarah Miller
Graduate Student
I'm a second year PhD candidate in the Neuroscience program. Prior to coming to Vanderbilt, I received a B.A in Biochemistry, Minor in Writing from Lafayette College and then spent two years at the National Institute of Health (NIH) studying structural biology. I joined the McMahon lab in May 2024 after spending my first year in the Interdisciplinary Graduate Program (IGP). My project in the lab is focused on circadian and photoperiod influences on motivated behavior in mice, with a dual focus on behavior and circuit mechanisms. Specifically, we are seeking to understand alterations in dopamine dynamics across mice raised in varied light conditions. Additionally, I am investigating photoperiodic effects on dopamine between female and male mice. Outside of lab, I love reading, video games, photography, and ultimate frisbee.
Abby Callahan-Muller
Learn about Abby!
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The McMahon lab is actively recruiting post-docs and graduate students.
Recent lab alumni
Dr. Olivia Cox
Ph. D. 2024
Olivia H. Cox is a Ph.D. candidate in neuroscience in the lab of Dr. Doug McMahon at Vanderbilt University. Her research focuses on the molecular underpinnings of the mammalian circadian clock, the suprachiasmatic nucleus (SCN). Specifically, she is interested in SCN plasticity and how environmental perturbations may affect core clock functioning on a molecular level. Currently, she is investigating these dynamics at the level of gene expression, e.g. genes that contribute to core mechanisms of the clock such as ability to entrain to seasonal photoperiods. Prior to graduate school, she spent 4 years as a laboratory technician studying epigenetics in the Department of Psychiatry at Johns Hopkins University. Her broader research interest is to combine tools from the fields of neuroscience and epigenetics in order to lay the molecular groundwork needed to solve circadian-related problems in human health.
Keith Kim
Lab Technician, 2023-2025
Hi! My name is Keith Kim, and I am a lab technician. I graduated from Vanderbilt University with a B.A in Neuroscience in May 2024 and have been working here since. Other things I like to do outside of lab are climbing, cooking, and keeping aquariums.
Ella Halbert
Research Assistant, 2024-2025
Ella joined the McMahon lab in January of 2024 as a research assistant, and she is broadly interested in the ways environmental cues shape brain function and behavior. Before joining the lab, Ella received a BA in Biology and Hispanic Studies from Oberlin College. As part of a National Science Foundation-Research Experience for Undergraduates (NSF-REU), Ella studied the ecological interactions between two frog species and Culex territans, the amphibian-biting mosquito. She also worked on various climate change and biodiversity projects in Acadia National Park in 2023. She hopes to continue working on ecologically-relevant research in the McMahon lab. Outside the lab, Ella enjoys reading, spending time outdoors, and crafting.
Manuel Giannoni-Guzmán, Ph. D.
Research Assistant Professor 2022-2025
Postdoctral Researher 2016-2022
Manuel A. Giannoni-Guzmán is an Assistant Professor of Biology at Middle Tennessee State University. His research focuses on the neural and molecular mechanisms of circadian rhythms in honey bees, exploring how these rhythms, essential for behaviors like navigation and time memory, are shaped by environmental factors. Outside the lab, Manuel enjoys powerlifting, reading, films, hiking, scuba diving, and FPS gaming.
Maya Anderson
Undergraduate Researcher & MARC scholar
Maya joined the McMahon lab in June of 2022 as a undergraduate researcher. She is currently a MARC scholar and is majoring in Neuroscience and Psychology. As a member of the lab, she has explored the role of temperature on entrainment of honey bee circadian rhythms and the development of a ex-vivo marker for honey bee circadian clock neurons. Post graduation, she hopes to pursue a Ph.D in the field of circadian rhythms. Outside of lab, her hobbies include ballroom dancing, drawing, and writing.
