Cell-specific loss of κ-opioid receptors in oligodendrocytes of the dysmyelinating jimpy mouse

Jimpy is a murine mutation in myelin proteolipid protein, leading to premature death of oligodendrocytes and severe central nervous system hypomyelination. Jimpy is a bona fide model of human Pelizaeus–Merzbacher disease. This paper describes a severe reduction in expression of κ-opioid receptors (KOP) in oligodendrocytes of jimpy mice. A cell-specific reduction of >90% is apparent by 5 days of age. Expression is not reduced in neurons, and μ-opioid receptor expression is normal. Mechanism(s) leading to deficient KOP expression in jimpy mice remain unclear. We speculate that loss of KOP may be related to increased [Ca2+]i and premature death of jimpy oligodendrocytes.