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Neuroimaging Model of Visceral Manipulation in an Awake Rat
Samuel R Cramer1, Xu Han2, Dennis C Y Chan2
1The Neuroscience Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802.
Summary
This study demonstrates non-anesthetized functional magnetic resonance imaging (fMRI) in rats during gastric distension. This novel approach reveals brain regions involved in visceral communication, advancing our understanding of homeostasis and allostasis.
Area of Science:
- Neuroscience
- Physiology
- Medical Imaging
Background:
- Bidirectional neuronal connections between internal organs and the nervous system are crucial for maintaining homeostasis and allostasis.
- Previous functional brain mapping of visceral communication used awake humans or anesthetized rodents, limiting mechanistic insights.
- New research paradigms are needed to explore visceral influences on brain states with greater detail and human translatability.
Purpose of the Study:
- To demonstrate the feasibility of non-anesthetized animal imaging during visceral manipulation.
- To refine mechanistic understanding of visceral-brain communication.
- To provide a translatable model for future neuroscience research.
Main Methods:
- Utilized a barostat with an implanted gastric balloon to cyclically distend the stomach of non-anesthetized male rats.
- Simultaneously acquired blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) data.
- Applied general linear modeling and spatial independent component analysis to analyze BOLD activation.
Main Results:
- Identified brain regions with BOLD activation temporally correlated with gastric distension.
- Observed widespread BOLD activation in the inferior colliculus, cerebellum, ventral midbrain, and hippocampal structures during the ON-OFF barostat pressure cycle (20-0 mmHg).
- Demonstrated the achievability of neuroimaging models for gastric manipulation in non-anesthetized rats.
Conclusions:
- Non-anesthetized fMRI during gastric manipulation is a feasible research model.
- This approach offers a pathway for more comprehensive studies integrating techniques like electrophysiology.
- The findings provide a foundation for deeper investigation into visceral-brain integration and its role in physiological regulation.
