Keywords

DRG Dorsal Root Ganglia, NG Nodose Ganglia, ENS Enteric Nervous System, GI Gastrointestinal, PIEZO1 and PIEZO2

Subject Categories

Anatomy | Cell and Developmental Biology | Neuroscience and Neurobiology

Abstract

The stomach is one of the most mechanically active organs in the body, undergoing continuous cycles of stretch, compression, and distension during food processing. To coordinate peristalsis, gastric accommodation, and satiety signaling, the organ relies on specialized mechanosensors. PIEZO1 and PIEZO2 are the primary mechanically activated ion channels in mammals, yet a systematic mapping of these channels within the gastric muscularis propria, where mechanical forces are generated and detected remained unavailable. This thesis employs immunohistochemistry paired with high-resolution microscopy to map PIEZO1 and PIEZO2 expression in mouse stomach flat-mount preparations and cryosections of the nodose and dorsal root ganglia (DRG). PIEZO1 was localized to three distinct compartments in the gastric muscularis propria. In the circular muscle layer, PIEZO1-positive fibers displayed a characteristic varicose bead-on-astring morphology consistent with intramuscular arrays (IMAs) originating from vagal nodose ganglia. PIEZO1 labeling was also observed in structures resembling intramuscular interstitial cells of Cajal (ICC-IM), and in fibers wrapping around myenteric neuron somata, which were themselves PIEZO1-negative. PIEZO1-positive neurons in both nodose ganglia and DRG confirm extrinsic sensory origin for these gastric fibers, with DRG positivity suggesting an additional spinal afferent contribution requiring verification through anterograde tracing. PIEZO2 immunoreactivity in the gastric wall was markedly limited. Sparse, weakly labeled cell profiles were detected in the muscle layers, but insufficient to permit definitive classification. Myenteric somata was PIEZO2-negative, consistent with PIEZO1 findings. Both nodose ganglia and DRG contained clear PIEZO2-positive sensory neurons, indicating iv that occasional PIEZO2 fibers likely represent extrinsic afferent terminals. The consistent soma-negative pattern across both channels in myenteric neurons provides the first anatomical evidence that PIEZO-immunoreactive structures in the gastric wall may arise from extrinsic sensory terminals, establishing a framework for future mechanosensory and neuromodulatory research.

Completion Date

2026

Semester

Summer

Committee Chair

CHENG, ZIXI

Degree

Master of Science (M.S.)

College

College of Medicine

Department

BURNETT SCHOOL OF BIOMEDICAL SCIENCES

Format

PDF

Document Type

Thesis

Language

English

Release Date

8-15-2028

Available for download on Tuesday, August 15, 2028

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