Glial support is critical for normal axon function and can become dysregulated in white matter (WM) disease. In humans, loss-of-function mutations of KCNJ10, which encodes the inward-rectifying potassium channel KIR4.1, causes seizures and progressive neurological decline. We investigated Kir4.1 functions in oligodendrocytes (OLs) during development, adulthood and after WM injury. We observed that Kir4.1 channels localized to perinodal areas and the inner myelin tongue, suggesting roles in juxta-axonal K+removal. Conditional knockout (cKO) of OL-Kcnj10 resulted in late onset mitochondrial damage and axonal degeneration. This was accompanied by neuronal loss and neuro-axonal dysfunction in adult OL-Kcnj10 cKO mice as shown by delayed visual evoked potentials, inner retinal thinning and progressive motor deficits. Axon pathologies in OL-Kcnj10 cKO were exacerbated after WM injury in the spinal cord. Our findings point towards a critical role of OL-Kir4.1 for long-term maintenance of axon function and integrity during adulthood and after WM injury.
KCNJ10 This gene encodes a member of the inward rectifier-type potassium channel family, Kir4.1, characterized by having a greater tendency to allow potassium to flow into, rather than out of, a cell. Kir4.1, may be responsible for the potassium buffering action of glial cells in the brain. It is highly expressed on astrocytes. However in oligodendrocytes it helps them help nerves to survive. Loose it and nerves dies eventually. Interesting science but one may need an alternative route to use therapeuticaly as this potassium channel is all over the place. Many years ago there was a claim that people with MS had antibodies against this channel. It was refuted by most other studies