Related Experiment Video
Updated: Mar 10, 2026
08:32
Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain
Published on: January 4, 2018
11.0K
Cephalic phase, reflex insulin secretion neuroanatomical and physiological characterization
H R Berthoud1,2, D A Bereiter1,2, E R Trimble1,2
1Laboratoires de Recherches Métaboliques, Institut de Biochimie Clinique, Switzerland.
Diabetologia
|December 13, 2016
Summary
The sweet taste of saccharin triggers a cephalic phase insulin response (CPIR) in rats, mediated by the autonomic nervous system. This reflex is crucial for normal glucose tolerance and may influence food behavior and obesity.
Area of Science:
- Neuroendocrinology
- Physiology
- Metabolic research
Background:
- The cephalic phase insulin response (CPIR) is an anticipatory release of insulin triggered by sensory stimuli associated with food.
- The neural pathways and physiological significance of CPIR, particularly in response to sweet tastes, require further elucidation.
Purpose of the Study:
- To investigate the neural mediation of the sweet taste-induced CPIR in rats.
- To explore the central neural pathways involved in this reflex.
- To assess the physiological relevance of CPIR in glucose tolerance and its potential role in dietary obesity.
Main Methods:
- Utilized chronically catheterized, freely moving male Wistar rats.
- Employed streptozotocin-induced diabetes model with intrahepatic islet transplantation for denervated beta-cell preparations.
- Conducted electrophysiological recordings and semi-micro central nervous system manipulations.
- Assessed oral glucose tolerance and behavioral responses to palatable foods.
Main Results:
- Saccharin reliably triggered CPIR without altering glycemia, indicating neural mediation via the autonomic nervous system.
- Denervated beta-cell preparations showed a complete lack of CPIR, confirming the absence of gastrointestinal hormonal involvement.
- CPIR demonstrated resistance to extinction, suggesting an unconditioned reflex component.
- Preliminary findings suggest CPIR organization at the brain stem/midbrain level with diencephalic modulation.
- Lack of CPIR led to pathological oral glucose tolerance; exaggerated CPIR was linked to behavioral reactions and dietary obesity.
Conclusions:
- The sweet taste-induced CPIR is neurally mediated by the peripheral autonomic nervous system, independent of gastrointestinal hormones.
- CPIR plays a significant physiological role in maintaining normal oral glucose tolerance.
- Dysregulation of CPIR may contribute to maladaptive eating behaviors and the development of obesity.
Related Concept Videos
01:27Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
2.9K
The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are...
Insulin and C-peptide are...
2.9K
01:05Insulin Secretory Vesicles
7.2K
Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
7.2K
01:37Neural Regulation
44.0K
Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food.
44.0K
01:24Cephalic Phase of Digestion
4.4K
The process of digestion is composed of three stages – cephalic, gastric, and intestinal – each with a distinct control center. The cephalic phase is the first stage, and it starts even before the food enters the stomach. It is controlled by the central nervous system and is initiated by any food-related sensory stimuli, such as the sight and smell of food, which send signals to the brain. While eating, the taste receptors intensify these signals, which travel to the cerebral cortex...
4.4K
01:29Intestinal Phase of Digestion
12.0K
The intestinal phase of digestion is the third and final stage of the digestive process, occurring after the cephalic and gastric phases. It begins when chyme, a partially digested mixture of food and digestive enzymes, enters the small intestine from the stomach. This phase is crucial for nutrient absorption and involves complex hormonal and enzymatic interactions.
The arrival of the chyme in the small intestine distends the duodenum, which triggers the enterogastric reflex. This distension...
The arrival of the chyme in the small intestine distends the duodenum, which triggers the enterogastric reflex. This distension...
12.0K
01:28Insulin: The Receptor and Signaling Pathways
5.4K
Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but...
5.4K