How did the brain become so complex? Beyond neurons, the brain contains many types of support cells called macroglia, which help with tasks like protecting nerve cells, guiding signals, and providing energy. These cells are essential for brain function, yet scientists still don't know when they first appeared in evolution. For a long time, researchers believed that the wide variety of macroglia seen in mammals—especially astrocytes—was a recent development, and that earlier animals like fish and amphibians had only simpler types. Our research challenges this idea. We are studying different vertebrates, from jawless fish to modern species, using advanced molecular and imaging techniques to trace when these cell types emerged and how they evolved. This work could push back the timeline for brain complexity by hundreds of millions of years and help us understand how the brain developed across species. These insights may also guide future research on brain health and disease.

2026

2030