This study explores how focal white matter lesions act as primary drivers of grey matter inflammation and synaptic loss, rather than being secondary symptoms of neurodegeneration. Using an anatomically precise olivocerebellar circuit model, researchers demonstrated that demyelination triggers a transient adaptive response involving reduced neuronal activity and microglial activation around cell bodies. Spatial transcriptomics and live imaging revealed that these microglia are not inherently destructive but perform a vital neuroprotective role by remodeling circuits to facilitate repair. Crucially, the research found that myelin regeneration is essential for resolving this inflammation; when remyelination completes, grey matter health returns to normal. Conversely, the failure of myelin to regenerate leads to chronic neuroinflammation, mimicking the low-grade damage observed in progressive Multiple Sclerosis and Alzheimer’s disease. Ultimately, the findings suggest that the functional integrity of grey matter is fundamentally coupled to the regenerative plasticity of white matter tracts.

References:

• de Faria Jr O, Vagionitis S, Lopez-Lopez A, et al. Focal white matter lesions drive grey matter inflammation and synapse loss[J]. Nature, 2026: 1-11.