The Neural Basis of Brain-Body Communication

Author: Wang, Tongtong

Year: 2026

Degree: Dissertation (Ph.D.)

Advisor: Oka, Yuki

Committee Members: Lester, Henry A.; Anderson, David J.; Mazmanian, Sarkis K.; Oka, Yuki

Option: Neurobiology

DOI: 10.7907/a8mn-0e75

Abstract

Understanding how the nervous system orchestrates physiology across the body has long been a central question in neuroscience. While neural mechanisms underlying behavior have been extensively characterized, the cellular and circuit principles that mediate brain-body communication remain underexplored. In this thesis, I investigate how internal physiological signals are detected and translated into coordinated regulation of organ functions through specialized sensory and autonomic pathways.

Using molecular, behavioral, and genetic perturbation approaches, I first examine how changes in body fluid balance are detected by central sensory neurons. I identify distinct neuronal populations within forebrain circumventricular regions that detect hyperosmotic and hypovolemic challenges and drive modality-specific fluid consumption behaviors. Then I show how water signals in the gut are encoded by a dedicated vagal afferent population, providing feed-forward inputs that contribute to thirst satiation. These studies demonstrate that internal states are monitored through specialized channels spanning central and peripheral circuits.

Next, I investigate the circuit logic of sympathetic regulation in the abdomen, identifying molecularly defined neuronal populations that project selectively to visceral organs and differentially regulate gastrointestinal transit and digestive processes. These results demonstrate that sympathetic outputs are organized into discrete pathways that enable precise and independent control of physiology. I then synthesize current knowledge of autonomic organization, highlighting its molecular diversity and modular architecture as key features enabling selective regulation of organ function.

Together, these findings reveal that brain-body communication is mediated by structured sensory pathways and modular autonomic circuits to achieve precise yet flexible control of physiology. This work provides a framework for understanding how neural systems coordinate internal stability and offers insight into how disruptions of these processes may contribute to diseases.

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