2020 Theses Doctoral

Feeding and Gastrointestinal Regulation: A Novel Domain of the Cerebellum

Birkenbach, Kathryn Elise

The cerebellum is well-known for its ability to integrate diverse internal and external stimuli, forming associations which serve as a basis for the construction of predictive models. Though traditionally studied in the context of motor learning, mounting evidence indicates that cerebellar learning may play an analogous role in many non-motor functions, including autonomic regulation and reward processing. Using combinatorial approaches of neuroanatomical tracing, electrophysiology, and behavioral studies, we investigated whether cerebellar learning extends to the domains of feeding behavior and gastrointestinal regulation, wherein prediction is critical for optimally timing food seeking and digestion in order to maximize nutrient acquisition while minimizing risk and energetic cost. Our results show direct anatomical connections between the cerebellum and known feeding centers, including the lateral hypothalamus, nucleus of the solitary tract, and parvocellular reticular nucleus. In addition, a localized area of the rostral cerebellum was found to respond to gastric distension and drive gastric emptying. Finally, we show that cerebellar activation drives robust, short-latency ingestive responses in awake, sated mice. Collectively, our results implicate the specific, interconnected cerebellar regions of Lobules II & III and the rostral fastigial nucleus, which we believe may represent one or more microzones devoted to integrating pre-and post-ingestive signals for control of feeding and digestion.