To compensate for microglial loss over time, microglia undergo mitosis and bone marrow derived progenitor cells migrate into the brain via the meninges and vasculature. Accumulation of minor neuronal damage that occurs during normal aging can transform microglia into enlarged and activated cells.
A neuron is a nerve cell that is the basic building block of the nervous system. Neurons are similar to other cells in the human body in a number of ways, but there is one key difference between neurons and other cells. Neurons are specialized to transmit information throughout the body.
Oligodendrocytes (from Greek, meaning 'cells with a few branches'), or oligodendroglia, are a type of neuroglia discovered by Pío del Río Hortega. Their main functions are to provide support and insulation to axons in the central nervous system of some vertebrates, equivalent to the function performed by Schwann cells in the peripheral nervous system.