The Human Brain : From Neurone to Nervous System

ASTROCYTES


  1. Astrocytes are star-shaped glial cells that are positioned between neurones and brain capillaries. They form the blood brain barrier, and take part in the regualation of local blood flow and the metabolism of neurotransmitters.

  2. Astrocytes are glial cells that have processes reaching from the nerve cell to local brain capillaries. They are believed to be the cellular basis of the Blood Brain Barrier, and are well positioned to regulate the selective movement of chemicals between the circulation and central neurones.

  3. Their position linking neurones and blood vessels also suggests that they may have a role to play in regulatling local bood flow within the brain. It is known that activity of areas of the cortex are associated with an increase in local blood flow.

  4. Astrocytes also metabolise neurotransmitters, and take part in the recycling of Glutamate and GABA using the glutamine cycle.

  5. Key Words: astrocytes, blood brain barrier, local blood flow, metabolism of neurotransmitters, glutamine cycle, glio-transmitters.