Single-cell RNA-seq has revealed >10 distinct reactive astrocyte states in neurodegeneration, collapsing the A1/A2 binary. Mapping these states to disease-stage, regional vulnerability, and functional output (trophic support vs synaptotoxicity) is needed to design astrocyte-targeted therapies.
Astrocytes adopt A1 (neurotoxic) and A2 (neuroprotective) phenotypes, but recent single-cell data reveals far greater heterogeneity. Mapping reactive subtypes to disease stages and therapeutic targets is needed.