Astrocytes: The Unsung Heroes of the Central Nervous System

🕒 Approximate reading time: 4 minutes

When it comes to the nervous system, neurons often steal the spotlight. Yet, there is another group of cells, known as astrocytes, that are proving to be equally important. This blog post will focus on these star-shaped cells, discussing their role in the central nervous system (CNS) and why they should no longer remain unsung.

Understanding Astrocytes

Astrocytes, named for their star-like shape, are a type of glial cell in the CNS. Unlike neurons, which are responsible for transmitting electrical signals, astrocytes play a supportive role. They help to maintain the homeostasis of the brain and spinal cord, provide nutrients to neurons, and take part in the repair and scarring process of the brain and spinal cord following injuries.

Roles in the CNS

Astrocytes are not merely supporting actors but play numerous crucial roles:

  1. Maintaining the Blood-Brain Barrier: Astrocytes' endfeet cover over 99% of the blood-brain barrier, helping to control the substances that pass from the blood to the brain and vice versa.

  2. Regulating Neurotransmission: They play an active role in modulating synaptic activity, helping to clear neurotransmitters from the synaptic cleft and recycling them.

  3. Providing Metabolic Support: Astrocytes supply neurons with essential nutrients and energy substrates, contributing to neuronal health and function.

  4. Neurogenesis and Synaptogenesis: Astrocytes secrete factors that influence the birth of new neurons and the formation of new synapses, thereby shaping neuronal networks.

Astrocytes in Disease

Astrocytes have been implicated in numerous neurological diseases, including Alzheimer's disease, multiple sclerosis, and amyotrophic lateral sclerosis (ALS). While it was previously thought that astrocytes were merely bystanders in disease progression, research is showing that they may have a more active role, contributing to disease progression or possibly offering avenues for treatment.

Research into Astrocyte Biology

Despite their importance, astrocytes remain less well-studied than neurons. However, this is beginning to change as we realise the key roles they play in the CNS. Greater insight into astrocyte biology could lead to new therapeutic strategies for a range of neurological conditions, marking an exciting frontier in neuroscience.


Astrocytes are far from being mere supporting players in the CNS. Instead, they're instrumental in maintaining brain function and health. While research is still ongoing, one thing is clear: these unsung heroes of the CNS deserve to take centre stage.