Oligodendrocyte Responses, Myelination, and Opioid Addiction Treatments

Buprenorphine and methadone are effectively used for the management of pregnant opioid-dependent addicts. However, little is known regarding potential effects of these long-lasting opioids on brain maturation. This chapter is focused on understanding the consequences of perinatal exposure to these drugs on developmental myelination. Recent findings indicated that perinatal exposure to therapeutic doses of either methadone or buprenorphine alter the timing and extent of myelin deposition in the developing rat brain. Parallel in vitro studies demonstrated that methadone and buprenorphine indeed exert drug and dose-specific direct effects on cells of the oligodendroglial lineage, altering their schedule of differentiation into mature oligodendrocytes capable of myelin formation. These findings support the idea of a crucial function of the endogenous opioid system in controlling the timing of oligodendrocyte maturation. Interfering with these regulatory systems by opioid use or opioid maintenance treatments could disrupt the normal process of myelin formation at critical stages of myelination and plasticity, in both the developing infant and adolescent brain.