Astrocytes – Location, Structure, and Function

Author: Scott A. Sheffield MS

Last update: Sep 26th, 2022

• Astrocytes are the most common support cell in the brain and spinal cord. Their thin cytoplasmic processes extend in all directions to make contact with capillaries, neurons, and other astrocytes.

• The processes that terminate on the capillaries expand into perivascular (end) feet, which cover the walls of these blood vessels.

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Research indicates that astrocytes perform many functions:

1. They help form a blood-brain-barrier by secreting chemicals that regulate how capillary endothelial cells transfer substances into the CNS from the blood.
2. They release lactose made from glucose, which neurons use for energy.
3. They remove excess neurotransmitter and K+.
4. They help regulate synaptic activity between neurons.
5. They help increase blood flow when neurons are most active.
6. Their microfilament-filled processes form a supportive network that helps hold neurons and blood vessels in place.
7. They release nerve growth factor (NGF) and other growth factors to stimulate neuron growth in the embryonic brain and after injuries.
8. They become phagocytic after injuries and help remove damaged tissues. If needed, they can also form glial scars.

Overview: