A spatial transcriptomics comparison of the adult versus metamorphosed axolotl brain.

The Mexican axolotl (Ambystoma mexicanum) is an established model for studying tetrapod regeneration and development. Notably, axolotls exhibit remarkable brain regeneration as adults, a trait rarely observed in other adult vertebrates. Adult axolotls can undergo metamorphosis, a process that induces dramatic remodeling of multiple organs and is accompanied by a gradual decline in regenerative capacity and lifespan. However, systematic studies on whole-brain cellular dynamics and molecular mechanisms in both adult and metamorphosed individuals remain lacking. Here, we profiled five representative brain regions (olfactory bulb, telencephalon, diencephalon/mesencephalon, rhombencephalon, and pituitary) of the axolotl brain via spatial transcriptomics in both adult and metamorphosed individuals. Our work reveals metamorphosis-associated changes in cell types and molecular profiles across brain regions.