Related Experiment Video
Updated: May 20, 2026
08:34
Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay
Published on: July 15, 2025
Insulin in the brain: there and back again.
William A Banks1, Joshua B Owen, Michelle A Erickson
1Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care Center, Seattle, WA, USA. wabanks1@uw.edu
Pharmacology & Therapeutics
|July 24, 2012
Summary
Central nervous system (CNS) insulin has unique functions, impacting feeding and cognition independently of glucose. Insulin resistance in the CNS is linked to neurological disorders, highlighting its critical brain roles.
Area of Science:
- Neuroscience
- Endocrinology
- Cell Biology
Background:
- Insulin, produced by the pancreas, has distinct functions in the central nervous system (CNS) beyond glucose metabolism.
- It crosses the blood-brain barrier (BBB) via a specific transporter, influencing feeding and cognition.
- CNS insulin actions may resemble ancestral insulin functions, differing from its peripheral metabolic roles.
Purpose of the Study:
- To explore the unique functions of insulin within the CNS.
- To investigate the mechanisms of insulin transport across the BBB and its regulation.
- To examine the implications of CNS insulin resistance in neurological conditions.
Main Methods:
- Review of existing literature on CNS insulin transport and signaling.
- Analysis of the role of brain endothelial cells (BECs) and pericytes in BBB insulin transport.
- Discussion of insulin signaling pathways (PI3K/Akt, MAPK) in the CNS.
Main Results:
- Insulin transport across the BBB is mediated by a saturable transporter on BECs, which is affected by hyperglycemia and diabetes.
- Pericytes are crucial for maintaining BBB integrity and insulin transport.
- CNS insulin resistance is associated with conditions like Alzheimer's disease and depression.
Conclusions:
- Insulin plays multifaceted roles in the CNS, involving unique signaling pathways.
- Dysregulation of CNS insulin transport and action contributes to neurological diseases.
- Further research is needed to fully understand the complex story of insulin in the brain.
More Related Videos
Related Concept Videos
01:27Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
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 co-secreted in...
Insulin and C-peptide are co-secreted in...
01:28Insulin: The Receptor and Signaling Pathways
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 this inhibition is released...
01:16Hormones Regulating Blood Glucose
Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
In addition to accelerating glucose uptake and utilization, insulin has...
01:05Insulin Secretory Vesicles
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...
01:25Insulin: Biosynthesis, Chemistry, and Preparation
The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide.
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses...
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses...
01:15Hypoglycemia and Glucagon
Without prolonged fasting, healthy individuals maintain blood glucose levels above 3.5 mM due to a well-adapted neuroendocrine counterregulatory system that effectively prevents acute hypoglycemia, a potentially life-threatening condition. The primary clinical scenarios for hypoglycemia encompass diabetes treatment, inappropriate production of endogenous insulin or insulin-like substances by tumors, and the use of glucose-lowering agents in non-diabetic individuals. Notably, hypoglycemia in the...