Dr. Mari Sosa is a systems neuroscientist driven to understand why some memories are stronger than others. She earned her Bachelor’s in Neurobiology from Harvard University and her PhD in Neuroscience with Dr. Loren Frank at University of California, San Francisco. In her PhD work, Mari used multi-region electrophysiology in behaving rats to study how neuronal networks between the hippocampus and nucleus accumbens may store specific aspects of experience during learning. As a postdoc with Dr. Lisa Giocomo at Stanford University, Mari's main work combined two-photon calcium imaging in mice with computational techniques, revealing how dynamic neuronal ensembles within the hippocampus amplify behaviorally relevant reward information while simultaneously preserving a stable map of space. Mari is a 2023 Leading Edge Fellow and was awarded a Helen Hay Whitney Postdoctoral Fellowship in 2021 and a BRAIN Initiative K99/R00 award from the NIMH in 2024/2026. 

The Sosa Lab opened at the University of Colorado Boulder in August 2025. Mari is thrilled to be launching her independent research program while hiking and exploring the beautiful Front Range of the Rockies!  

Yessenia Mancha holds a B.A. in Neuroscience and Psychology from the University of Colorado Boulder. She is passionate about exploring neuronal and glial dynamics that influence learning and memory formation, particularly in the context of disease and physiological states. Her previous research experience includes studying oligodendrocytes and myelin dynamics in multiple sclerosis, as well as investigating novel innate behaviors in the interpeduncular nucleus (IPN). Outside the lab, she enjoys concerts, coffee shops, traveling, hiking, reading, and all things cozy and adventurous.

Dr. David Protter is a Research Associate who has worked in wide-ranging fields, from protein biophysics to rodent behavior. He earned his B.A. in Biochemistry, Biophysics, and Molecular Biology at Whitman College (go sweet onions!) and his PhD in Biochemistry with Dr. Roy Parker at the University of Colorado, Boulder (go buffs!). David is a curious tinkerer by nature who loves learning new techniques and new instruments while seeking to understand how systems work mechanistically.

In his PhD, David explored the biochemical mechanisms allowing RNA binding proteins to segregate into non-membrane bound cellular compartments via phase separation. In his post-doc and subsequent Research Associate position with Dr. Zoe Donaldson (CU Boulder, go voles!) he led development of an in-house operant behavioral system for measuring social motivation while performing miniscope calcium imaging in monogamous prairie voles. He also gained training and passion for high-density electrophysiology recording techniques in freely moving animals.

As a Staff Scientist in the Sosa Lab, David is focused on computational approaches for understanding how animals properly and aberrantly encode information related to reward, and occasionally providing emergency 3D design and printing services.

Dr. Ellen DeGennaro is an interdisciplinary scientist driven to understand how the brain works across multiple scales. She earned a dual bachelors degree in Cognitive Science and Music from Vassar College, and afterwards got her start in systems neuroscience and lab management with Dr. Robert Desimone at MIT. She then went on to obtain a PhD in Medical Engineering with a focus on Brain and Cognitive Sciences from the Harvard-MIT Program in Health Sciences and Technology. For her doctoral research with Dr. Christopher A. Walsh, she studied the genetic mechanisms regulating brain development and human brain evolution, and developed a genetic barcoding-based method for studying cell lineages. Ellen is also passionate about public health, having led outreach efforts during the pandemic before her postdoc in computational epidemiology with Dr. Daniel Larremore at CU Boulder. She brings her experimental, computational, and operational expertise to her role as Lab Manager / Staff Scientist in the Sosa lab, where she’s excited to learn more about learning, develop image analysis pipelines, and build some sweet databases. Outside the lab she enjoys performing with the Ars Nova Singers, creating things at The Company, and playing soccer with a great view of the Flatirons.

Lab Alumni

Francesco Fulghieri - Undergraduate Researcher