What does astrocyte mean?
An astrocyte is a star-shaped cell found in the central nervous system — the brain and spinal cord — belonging to a family of non-neuronal cells known as glia. Its name derives from its branching, star-like appearance under the microscope. Astrocytes play essential supporting roles in neural function: they help form and maintain the blood–brain barrier, regulate the balance of ions and neurotransmitters around synapses, supply neurons with nutrients, and contribute to repair processes after injury. Neuroscientists distinguish several subtypes, including protoplasmic astrocytes in grey matter and fibrous astrocytes in white matter. The term appears chiefly in scientific, medical, and academic writing rather than everyday speech. Interest in astrocytes has grown considerably in recent decades as research has revealed that they do far more than merely support neurons — they participate actively in signalling, synaptic plasticity, and disease states such as Alzheimer's and multiple sclerosis, making them a central subject of modern neuroscience.
nounA star-shaped glial cell of the central nervous system that supports neurons, regulates the chemical environment of the brain, and helps maintain the blood–brain barrier.
- A star-shaped glial cell of the central nervous system that supports neurons, maintains the blood–brain barrier, and regulates the brain's chemical environment.
"Astrocytes surround synapses throughout the brain, where they help regulate neurotransmitter levels."
"When neurons fire repeatedly, nearby astrocytes help clear excess neurotransmitters from the synaptic cleft."
"In neurodegenerative diseases such as Alzheimer's, researchers have observed marked changes in reactive astrocytes."
Standard English plural, formed by adding -s. Commonly used in scientific texts when discussing populations or types of these cells.
"Reactive astrocytes proliferate near sites of injury in the brain."
You have billions of star-shaped cells in your head quietly running the brain's housekeeping — and they're literally named after stars.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of astrocyte
The word astrocyte comes from the Greek roots 'astron', meaning star, and 'kytos', meaning cell or hollow vessel, combined with the suffix '-cyte' used in biology to denote cells. It was coined in the late nineteenth century by German anatomists who observed these star-shaped cells in stained brain tissue. The same Greek root 'astron' gives us related English words such as astronomy, asteroid, and astronaut, while '-cyte' appears in many other cell names such as erythrocyte and lymphocyte.
Related word forms
How astrocyte is actually used
A technical term used almost exclusively in neuroscience, medicine, and biology; rare in everyday conversation. Plural is 'astrocytes'.
Easily confused with astrocyte
An oligodendrocyte is a different type of glial cell that forms myelin sheaths around neurons in the central nervous system, whereas an astrocyte is star-shaped and provides metabolic and structural support.
Microglia are the immune cells of the brain, while astrocytes primarily provide structural, metabolic, and regulatory support to neurons.