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
Perisynaptic schwann cells 12-13 in rats. Schwann cell precursors then differentiate into Immature Schwann cells from which myelinating and non-myelinating Schwann cells are directly descended. These cells generally appear around embryonic day 13-15 in rats. The differentation of Immature Schwann cells occurs after birth and is dependent on the axons in which the glia are associated. This differentation is known to be reversible, as seen in regeneration models. Perisynaptic Schwann cells develop as non-myelinating Schwann cells and encapsulate the NMJ. PSCs can be attributed to glial lineage by the presence of Calcium binding proteins S100, Glial fibrillary acidic protein (GFAP), and Protein 0.