Human brain the largest cells (by size of cell body) in the nervous system. The adult human brain is estimated to contain 86±8 billion neurons, with a roughly equal number (85±10 billion) of non-neuronal cells. Out of these neurons, 16 billion (19%) are located in the cerebral cortex, and 69 billion (80%) are in the cerebellum. Types of glial cell are astrocytes (including Bergmann glia), oligodendrocytes, ependymal cells (including tanycytes), radial glial cells and microglia. Astrocytes are the largest of the glial cells. They are stellate cells with many processes radiating from their cell bodies. Some of these processes end as perivascular
Satellite glial cell these cells. Current research is revealing that SGCs are also able to respond to some of the same chemical stimuli as neurons. The research is ongoing and SGCs role in injury repair mechanisms is not yet fully understood. Glial cells, including SGCs, have long been recognized for their roles in response to neuronal damage and injury. SCGs have specifically been implicated in a new role involving the creation and persistence of chronic pain, which may involve hyperalgesia and other forms of spontaneous pain. SGCs have the ability to release cytokines and other bioactive molecules that transmit pain neuronally. Neurotrophins and