TY - JOUR VL - 219 N1 - This article is available under a Creative Commons License (Attribution 4.0 International, as described at https://creativecommons.org/licenses/by/4.0/). JF - Journal of Cell Biology A1 - Marshall-Phelps, KLH A1 - Kegel, L A1 - Baraban, M A1 - Ruhwedel, T A1 - Almeida, RG A1 - Rubio-Brotons, M A1 - Klingseisen, A A1 - Benito-Kwiecinski, SK A1 - Early, JJ A1 - Bin, JM A1 - Suminaite, D A1 - Livesey, MR A1 - Möbius, W A1 - Poole, RJ A1 - Lyons, DA KW - Cell signaling Y1 - 2020/07/06/ TI - Neuronal activity disrupts myelinated axon integrity in the absence of NKCC1b AV - public N2 - Through a genetic screen in zebrafish, we identified a mutant with disruption to myelin in both the CNS and PNS caused by a mutation in a previously uncharacterized gene, slc12a2b, predicted to encode a Na+, K+, and Cl? (NKCC) cotransporter, NKCC1b. slc12a2b/NKCC1b mutants exhibited a severe and progressive pathology in the PNS, characterized by dysmyelination and swelling of the periaxonal space at the axon?myelin interface. Cell-type?specific loss of slc12a2b/NKCC1b in either neurons or myelinating Schwann cells recapitulated these pathologies. Given that NKCC1 is critical for ion homeostasis, we asked whether the disruption to myelinated axons in slc12a2b/NKCC1b mutants is affected by neuronal activity. Strikingly, we found that blocking neuronal activity completely prevented and could even rescue the pathology in slc12a2b/NKCC1b mutants. Together, our data indicate that NKCC1b is required to maintain neuronal activity?related solute homeostasis at the axon?myelin interface, and the integrity of myelinated axons. IS - 7 UR - https://doi.org/10.1083/jcb.201909022 ID - discovery10098423 ER -