| First Author | Kole K | Year | 2022 |
| Journal | Nat Commun | Volume | 13 |
| Issue | 1 | Pages | 7598 |
| PubMed ID | 36494349 | Mgi Jnum | J:349856 |
| Mgi Id | MGI:7410269 | Doi | 10.1038/s41467-022-35350-x |
| Citation | Kole K, et al. (2022) Parvalbumin basket cell myelination accumulates axonal mitochondria to internodes. Nat Commun 13(1):7598 |
| abstractText | Parvalbumin-expressing (PV(+)) basket cells are fast-spiking inhibitory interneurons that exert critical control over local circuit activity and oscillations. PV(+) axons are often myelinated, but the electrical and metabolic roles of interneuron myelination remain poorly understood. Here, we developed viral constructs allowing cell type-specific investigation of mitochondria with genetically encoded fluorescent probes. Single-cell reconstructions revealed that mitochondria selectively cluster to myelinated segments of PV(+) basket cells, confirmed by analyses of a high-resolution electron microscopy dataset. In contrast to the increased mitochondrial densities in excitatory axons cuprizone-induced demyelination abolished mitochondrial clustering in PV(+) axons. Furthermore, with genetic deletion of myelin basic protein the mitochondrial clustering was still observed at internodes wrapped by noncompacted myelin, indicating that compaction is dispensable. Finally, two-photon imaging of action potential-evoked calcium (Ca(2+)) responses showed that interneuron myelination attenuates both the cytosolic and mitochondrial Ca(2+) transients. These findings suggest that oligodendrocyte ensheathment of PV(+) axons assembles mitochondria to branch selectively fine-tune metabolic demands. |
