A new, first-of-its-kind 3D map of the lamprey brain reveals that the common ancestor of all vertebrates possessed a surprisingly sophisticated brain architecture as far back as 450 million years ago. The study, published in Science on June 18, 2026, used single-cell transcriptomics to chart every cell in the brain of a jawless fish that has remained virtually unchanged for 360 million years.
What Researchers Did and Found
Led by SU Bing from the Kunming Institute of Zoology, Chinese Academy of Sciences, along with teams from BGI-Research and Liaoning Normal University, the researchers built a high-resolution, three-dimensional atlas showing both the exact positions and active gene expression of every cell in the lamprey brain. When they compared this ancient blueprint to modern mouse brains, they found strikingly conserved gene-expression patterns across core brain regions—meaning our shared ancestor already had a highly organized, complex brain.
One of the most fascinating discoveries was a cell type called anamniote-enriched neurons (AENs), which can simultaneously release both excitatory and inhibitory signals—a kind of "moonlighting" role. These versatile neurons are common in lampreys and zebrafish but rare in reptiles, birds, and mammals (amniotes). In mammals, after ancient whole-genome duplications, these generalists evolved into dedicated specialist neurons, each with a single, precise function.
The atlas also highlighted lineage-specific innovations: the lamprey sports oversized "Müller cells" and unique midbrain configurations, whereas mammals later developed a layered neocortex. Additionally, the study identified a primitive "cerebellum-like region" in lampreys, proving that the brain's coordination hubs began taking shape long before jaws evolved.
Why This Matters for Understanding Your Own Brain
This discovery reshapes our understanding of how intelligence evolved. The fact that a jawless fish shares deep molecular similarities with your own brain suggests that the basic blueprint for complex cognition is ancient and fundamental. It also shows that evolution can tinker with versatile neurons—like the AENs—to generate both simple and elaborate brain circuits. For anyone curious about their own cognitive abilities, this research underscores that many of our brain's core functions are inherited from ancestors that lived hundreds of millions of years ago. Understanding these ancient roots can help us appreciate both the continuity and the unique adaptations that make human intelligence possible.
What You Can Do
While you can't rewind evolution, you can keep your brain flexible by challenging it with new tasks. Learning new skills—like a language, musical instrument, or even brain-training puzzles—encourages your neurons to form new connections, a process called neuroplasticity. Try mixing up your routine to keep your "moonlighting" neurons active.
Source: Neuroscience News
Curious about your own brain? Take our free adaptive IQ test or try 306 brain training levels.
