A neuronal circuit driven by GLP-1 in the olfactory bulb regulates insulin secretion.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39138162.
- Also identified by DOI 10.1038/s41467-024-51076-4 and PMC identifier 11322178.
- Licence recorded as CC BY-NC-ND.
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Abstract
Glucagon-like peptide 1 (GLP-1) stimulates insulin secretion and holds significant pharmacological potential. Nevertheless, the regulation of energy homeostasis by centrally-produced GLP-1 remains partially understood. Preproglucagon cells, known to release GLP-1, are found in the olfactory bulb (OB). We show that activating GLP-1 receptors (GLP-1R) in the OB stimulates insulin secretion in response to oral glucose in lean and diet-induced obese male mice. This is associated with reduced noradrenaline content in the pancreas and blocked by an α<sub>2</sub>-adrenergic receptor agonist, implicating functional involvement of the sympathetic nervous system (SNS). Inhibiting GABA<sub>A</sub> receptors in the paraventricular nucleus of the hypothalamus (PVN), the control centre of the SNS, abolishes the enhancing effect on insulin secretion induced by OB GLP-1R. Therefore, OB GLP-1-dependent regulation of insulin secretion relies on a relay within the PVN. This study provides evidence that OB GLP-1 signalling engages a top-down neural mechanism to control insulin secretion via the SNS.
Medical subject headings
- Glucagon-Like Peptide 1
- Olfactory Bulb
- Insulin Secretion
- Glucagon-Like Peptide-1 Receptor
- Paraventricular Hypothalamic Nucleus
- Mice, Inbred C57BL