Complex sentence: Schwann cells and oligodendrocytes have similar functions in the central respectively peripheral nervous system, both acting to myelinate axons, which acts as a form of insulation allowing for better and faster proliferation of electrical signals along the nerves.
Split into simpler sentences: Schwann cells and oligodendrocytes have similar functions in the central and peripheral nervous system respectively. Both act to add myelin sheaths to the axons, which acts as a form of insulation allowing for better and faster proliferation of electrical signals along the nerves.