Talk Title: Dynamics of the caudal brainstem during behavior

Abstract: The caudal brainstem is uniquely positioned to regulate brain-body communication as it receives direct input from viscera-innervating vagal afferents and also contains specialized neurons that lie outside the blood-brain barrier that can directly sense circulating signals. Nevertheless, how different neurons in the caudal brainstem represent these neural and humoral signals remains poorly understood. Here, we performed calcium imaging in awake behaving mice to investigate how these signals are integrated in the caudal brainstem and used to control behavior. We identified three neuronal populations that separately and selectively encode ingestive, aversive, and hemodynamic signals. Notably, these neurons can sense these signals through slow-acting hormones but also through fast neural mechanisms. Together, these findings reveal parallel, functionally specialized neural representations within the caudal brainstem that encode distinct classes of internal signals.

Bio: Alejandro Lopez received his PhD from Rockefeller University where he worked in the lab of Dr. Cori Bargmann and was supported by an NIH F31 Predoctoral NRSA fellowship, and his MD from Weill Cornell Medicine. He then went on to complete an Internal Medicine Residency at the University of California, San Francisco. He is currently a Postdoctoral Researcher and a Gastroenterology Fellow at the University of California, San Francisco under the mentorship of Dr. Zachary Knight. He was awarded the HHMI Hanna Gray Fellowship in 2025. He is focusing on understanding how the body and the brain communicate to control feeding and the physiology of ingestion, with the long-term goal of advancing treatments for conditions like obesity and disorders of gut-brain interaction.

Followed by a reception with food and drink in 3^rd floor atrium