GLIAL CELL TYPES
Astrocytes provide structural isolation of neurons and
their synapses and provide ionic (K+) sequestration, trophic
support, and support for growth and signaling functions to neurons.
Oligodendroglia (oligodendrocytes) provide myelination of axons in the CNS.
Microglia are scavenger cells that participate in phagocytosis, inflammatory
responses, cytokine and growth factor secretion, and some immune reactivity in
the CNS. Perivascular cells participate in similar activities at sites near the
blood vessels. Schwann cells provide myelination, ensheathment, trophic
support, and actions that contribute to the growth and repair of peripheral
neurons. Activated T lymphocytes normally can enter and traverse the CNS for
immune surveillance for a period of approximately 24 hours.