What are the types of glial cells present in the central nervous system and their functions?

I - Oligodendrocytes are contained in axonal myelin sheaths.

II - Microglia represents the immune cells in the nervous system.

III - Ependymal cells are located in ventricular zones, performing barriers, and provide stem cells.

IV - Astrocytes participate in neuronal energy support by capturing ions, water, glucose, and regulating neurochemical actions in synaptic clefts, recapturing neurotransmitters.