Researchers have constructed the first three-dimensional, single-cell atlas of a lamprey brain, revealing that the common ancestor of all vertebrates possessed a complex, well-organized neural structure. Published in the journal Science, the study led by SU Bing of the Kunming Institute of Zoology demonstrates that despite 450 million years of evolutionary divergence, lamprey gene-expression patterns mirror those found in modern mammals like mice.
How does the lamprey brain reveal human origins?
The lamprey serves as a biological time capsule because its body plan has remained largely unchanged for approximately 360 million years. By mapping every cell and its corresponding gene activity, the research team identified that many fundamental brain regions are shared across the vertebrate lineage. According to the study, this indicates that the blueprint for a complex brain was already established before jawed and jawless vertebrates split. While mammals eventually developed a layered, highly specialized cortex, the lamprey retains unique midbrain neurons and oversized “Müller cells,” providing a clear look at the ancestral neural template.
Lampreys are often called “living fossils.” Their neural architecture provides a direct comparison to the earliest vertebrates, allowing scientists to strip away millions of years of evolutionary “add-ons” to see the brain’s original design.
What is the significance of “moonlighting” neurons?
The atlas highlights a transition from versatile, multi-purpose neurons to highly specialized cells. In lampreys, many cells act as “moonlighting” neurons—technically known as anamniote-enriched neurons (AENs)—which carry both excitatory and inhibitory signals simultaneously. Data from the Kunming Institute of Zoology shows these cells are common in jawless vertebrates but rare in jawed species. Jawed animals, including humans, largely replaced these versatile cells with “specialist” neurons designed for dedicated, high-speed tasks. This shift in neuronal function tracks with ancient whole-genome duplication events that allowed for increased biological complexity.
Are there early signs of the human cerebellum in lampreys?
The study suggests the cerebellum, the brain’s coordination center, has deeper roots than previously assumed. Researchers identified lamprey cells that share characteristics with cerebellar neurons, pointing to the existence of a diffuse, primitive “proto-cerebellum.” This suggests that the structural foundations for complex movement and motor coordination were present in the common ancestor of all vertebrates, long before the evolution of the elaborate structures seen in modern animals.
When researching evolutionary neuroscience, look for studies that utilize single-cell RNA sequencing. This technology is currently the gold standard for identifying cell types across different species and is fueling the next decade of comparative brain research.
What are the future trends in evolutionary neuroscience?
The ability to map an entire brain at single-cell resolution will likely shift the focus toward “molecular evolution”—the study of how specific gene-switching patterns create new brain functions. Future research will likely compare this lamprey atlas against other anamniote lineages to pinpoint exactly when the transition to specialist neurons occurred. By identifying these conserved gene networks, scientists hope to better understand the deep history of the human mind and the genetic basis of complex neural disorders.
Frequently Asked Questions
Why was the lamprey chosen for this brain study?
The lamprey is a jawless, eel-like fish that has undergone minimal physical changes over 360 million years, making it an ideal model for studying the ancestral vertebrate brain.
What is a single-cell atlas?
It is a high-resolution map that identifies the location of every cell in an organ and records which genes are active within those cells.
Do humans share brain structures with lampreys?
Yes. The study found that despite millions of years of separation, lampreys and mice share strikingly similar gene-expression patterns in many brain regions.
What do you think about the origins of the human brain? Join the discussion below or subscribe to our newsletter for more updates on the latest breakthroughs in evolutionary biology.