Researchers at Stanford University School of Medicine have made a fundamental discovery in neuroscience: the human brain, it turns out, is formed from two separate groups of progenitor cells that merged into a single organ over the course of evolution. ScienceDaily reports this, according to infohub.kz.
The study was led by Kyle Loh, an assistant professor of developmental biology. For decades, the scientific community held that all parts of the human brain develop from a single population of progenitor cells. However, the new research shows that the brain actually consists of two ancient nervous systems with distinct evolutionary origins.
In experiments, researchers Caroline Dondes and Rian Johai found that the forebrain and midbrain develop from cells expressing the Otx2 gene, while the hindbrain forms exclusively from cells expressing the Gbx2 gene. These two cell populations remain separate at the earliest stages of embryonic development and do not overlap.
An analysis of the evolutionary tree showed that this dual system arose more than 550 million years ago and is found in chickens, zebrafish, and acorn worms.
The discovery allowed researchers to grow human hindbrain neurons from stem cells in the laboratory for the first time. This breakthrough opens up broad possibilities for studying the causes and finding treatments for severe neurological disorders of the brainstem, such as amyotrophic lateral sclerosis and spinal muscular atrophy. In the future, the authors plan to study in detail the mechanisms of interaction between these two systems.