Text written in Basque and translated automatically by Elia without any subsequent editing. SEE ORIGINAL

The brain is made up of two parts of different origin

This could be a feature that has been in evolution for 550 million years.

For decades, scientists have believed that the entire brain develops from a single original cell type. However, a study published in the journal Nature Neuroscience proposes that two types of cells are needed and that a part of the brain develops from each type.

“One part of the brain is essential for several basic functions, and the other is key to reasoning and planning.”

Using mouse embryos, the authors conclude that from a precursor cell type, rhombencephalus, part of the brain, develops. This part of the brain is essential for basic functions such as heartbeat and breathing. From the other precursor cell type, two structures are developed, according to the authors: prosencephalon and mesencephalon. This first structure is key for reasoning and planning.

To find out when this form of brain development emerged in evolution, researchers searched for these two precursor cell types in different animals and found them in all the animals studied: monkeys, chickens, fish and even in the marine invertebrate Saccoglossus kowalevskii.

“Research can help us better understand neurodegenerative diseases.”

Interestingly, to find the common ancestor between man and this marine invertebrate, it takes 550 million years to evolve. Therefore, the authors suggest that this process of dual-origin development of the brain remained in evolution throughout these years and was shared among many animals.

The invention may also have practical application. In fact, they have succeeded in growing rhombencephalic neurons from stem cells, which can contribute to a better understanding of neurodegenerative diseases such as amyotrophic lateral sclerosis and Werdnig-Hoffmann's disease.