Study of Myelin Gene Expression in the Central Nervous System Using Real-Time PCR

Myelin sheaths are crucial for the survival and maintenance of the axons and the rapid propagation of the action potential. The glial cells involved are Schwann cells in the peripheral nervous system (PNS) and oligodendrocytes in the central nervous system (CNS). One oligodendrocyte may myelinate over 40 axons. In the CNS, myelin is composed of several layers of cytoplasmic membrane from oligodendrocytes stabilized by structural myelin-specific proteins such as proteolipid protein (PLP) and myelin basic protein (MBP). Those genes are expressed during myelination and then silenced. They can be re-expressed after demyelinating episodes, where they contribute to remyelination. Demyelination occurs after injuries of the CNS such as traumatic brain injury or during acute episodes of neurodegeneration observed in demyelinating and neurodegenerative diseases. Remyelination process is achieved by oligodendrocytes newly generated following the recruitment and differentiation of oligodendrocyte precursor cells (OPCs). Failure of remyelination process leads to irreversible axonal loss, functional impairment, and finally decreased cognitive performances. Several techniques have been described to study myelination and remyelination in culture systems. In this chapter, we explain how we can study myelin genes' expression in oligodendrocytes by real-time polymerase chain reaction (RT-PCR) using specific primers for plp and mbp. This technique can be crucial and prompt to determine the effect of specific chemicals (such as pesticides) on the myelination process in oligodendrocytes.