Astrocytes

Astrocytes are star-shaped glial cells of the central nervous system. Long considered merely supportive cells, they regulate communication between neurons, form and maintain the blood-brain barrier, and are now viewed as key players in information processing.

Astrocytes are involved in gliosis; “a healing process for lesions in the nervous system.” They also act at synapses to capture neurotransmitters such as glutamate and GABA released into the synaptic cleft.

Other roles include:

• Preventing neuronal hyperexcitation, which can lead to disorders such as epilepsy.

• They buffer K+ ions and play a trophic role by promoting neuronal growth and cellular signaling.

• They regulate the concentration of K+ ions, which is essential for maintaining optimal neuronal electrical potential.

• They possess specific channels that allow them to absorb, redistribute, or release ions according to local physiological needs.