Related Experiment Video
Updated: Jul 6, 2026
06:19
Reconstruction of the Blood-Brain Barrier In Vitro to Model and Therapeutically Target Neurological Disease
Published on: October 20, 2023
Water entry into astrocytes during brain edema formation
Gabriele Nase1, P Johannes Helm, Rune Enger
1Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo and CMBN, Blindern, NO-0317 Oslo, Norway.
Glia
|March 21, 2008
Summary
Brain edema involves astrocytes swelling significantly, with water entering these glial cells during initial stages. This cellular-level insight aids in developing better brain edema therapies.
Area of Science:
- Neuroscience
- Cell Biology
- Pathophysiology
Background:
- Brain edema formation is well-studied macroscopically.
- Cellular-level water fluxes and volume changes during early brain edema remain poorly understood.
- Understanding microscopic events is crucial for improved prevention and therapy.
Purpose of the Study:
- To investigate cellular volume changes in vivo during the initial phase of brain edema.
- To monitor water fluxes at the astrocyte level during hypo-osmotic stress.
Main Methods:
- Utilized a systemic hyponatremia model in transgenic mice.
- Employed two-photon laser scanning microscopy for in vivo imaging.
- Measured volume responses of glial cells (astrocytes) in the cerebellum and visual cortex.
Main Results:
- Individual astrocytes exhibited a position-dependent volume increase of twofold or more during edema.
- Demonstrated in vivo monitoring of cellular volume changes during brain edema.
- Identified astrocytes as primary sites of water entry in early brain edema.
Conclusions:
- Astrocytes undergo substantial volume increases in the initial phase of brain edema.
- Aquaporin-4 expression in astrocytes likely mediates this rapid water uptake.
- Findings provide critical cellular insights into brain edema pathogenesis.
Related Concept Videos
01:22Cerebral Edema ll: Pathophysiology
Vasogenic edema is a major form of cerebral edema characterized by abnormal accumulation of fluid in the brain’s extracellular space due to disruption of the blood–brain barrier (BBB). The BBB is a specialized structure composed of endothelial cells connected by tight junctions, supported by astrocytic endfeet and a basement membrane. Under normal conditions, it tightly regulates the movement of ions, proteins, and solutes between the bloodstream and brain parenchyma. When this barrier loses...
01:19Cerebral Edema l: Introduction
Cerebral edema is a pathological increase in brain water content that disrupts intracranial pressure regulation and impairs neurological function. Because the cranial vault is rigid, even modest increases in tissue volume can compromise cerebral perfusion, distort neural structures, and initiate secondary injury. Cerebral edema develops through four principal mechanisms: vasogenic, cytotoxic, interstitial, and ionic.Vasogenic EdemaVasogenic edema arises from disruption of the blood–brain...
01:21Cytotoxic Edema: Pathophysiology
Cytotoxic edema is a form of cerebral edema characterized by intracellular swelling of neurons, astrocytes, and other glial cells. It develops when the mechanisms responsible for maintaining ionic gradients across the cell membrane become impaired. Under normal physiological conditions, the sodium–potassium ATPase actively transports sodium ions out of the cell and potassium ions into the cell, preserving osmotic balance and enabling electrical signaling. This pump requires a continuous supply...
00:49The Blood-brain Barrier
Overview
01:23Transcellular Transport of Solutes
Transcellular transport of solutes is the movement of substances like monosaccharides and amino acids through polarized cells. This transport mechanism is primarily seen in epithelial and endothelial cells aided by membrane transport proteins such as channels and transporters. The tight junctions between these cells confine the membrane proteins to the two sides of the cell. The epithelial cells have distinct apical and basolateral domains. In contrast, the endothelial cells show the luminal...
01:29Increased Intracranial Pressure ll: Pathophysiology
Increased intracranial pressure (ICP) refers to a potentially life-threatening rise in pressure inside the skull. This usually happens when there is a major change in the volume of brain tissue, blood, or cerebrospinal fluid (CSF) — the three components inside the skull. According to the Monro-Kellie doctrine, if the volume of one component increases, the volumes of the other components must decrease to maintain normal pressure. If this does not happen, ICP rises.The process often begins with...