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Published on: August 24, 2016
Glucagon signaling modulates sweet taste responsiveness
Amanda E T Elson1, Cedrick D Dotson, Josephine M Egan
1Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 S. Penn St., Rm. S251, Baltimore, MD 21201, USA.
Summary
Glucagon enhances sweet taste perception by acting locally in the tongue. This finding reveals a new role for glucagon in regulating taste and food intake, impacting nutritional decisions.
Area of Science:
- Neuroscience
- Endocrinology
- Sensory Biology
Background:
- The gustatory system is crucial for evaluating food quality and nutritional content.
- Physiological mechanisms modulating taste based on nutritional needs can optimize food intake.
- Glucagon is vital for glucose homeostasis and may influence ingestive behavior.
Purpose of the Study:
- To investigate the role of glucagon in modulating taste responsiveness.
- To determine if glucagon acts locally within the gustatory system.
- To understand the impact of glucagon signaling on sweet taste perception.
Main Methods:
- Immunohistochemistry and confocal microscopy to detect glucagon and its receptor (GlucR) in mouse taste receptor cells.
- Genetic manipulation (Scg5(-/-) mice lacking glucagon) and pharmacological inhibition (GlucR antagonist L-168,049) in behavioral taste tests.
- Brief-access taste tests to assess responsiveness to sucrose and other taste stimuli (salty, sour, bitter).
Main Results:
- Glucagon and GlucR are coexpressed in a subset of mouse taste receptor cells, often co-localizing with T1R3 receptors.
- Mice lacking glucagon (Scg5(-/-)) showed significantly reduced sucrose responsiveness compared to wild-type controls.
- Pharmacological blockade of GlucR with L-168,049 acutely reduced sweet taste responsiveness.
- No significant differences in responses to salty, sour, or bitter stimuli were observed.
Conclusions:
- Local glucagon signaling in the gustatory epithelium plays a significant role in modulating sweet taste responsiveness.
- Glucagon's action on taste perception is specific to sweet stimuli, not affecting other basic tastes.
- This peripheral mechanism highlights a novel link between metabolic status (via glucagon) and sensory perception of nutrients.
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