Illustration of astrocyte cells. Astrocytes are a type of glial cell in the central nervous system that play a variety of important functions. They are involved in regulating the concentration of neurotransmitters in the synaptic cleft, maintaining the blood-brain barrier, providing metabolic support to neurons, and modulating synaptic plasticity. Additionally, astrocytes have been implicated in a range of neurological disorders, including Alzheimer's disease, epilepsy, and multiple sclerosis.