‘Textbook’ view of brain and spinal cord development revisited

For decades, biology textbooks have taught that developing nerve cells initially form the brain and over time, some transform into spinal cord, but a new study from researchers at the Francis Crick Institute challenges this view.

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For decades, biology textbooks have taught that…

but a new study…

challenges this view.

a critical decision is made earlier in cells than previously anticipated and this predetermines whether they form the brain or spinal cord.

Running from head to tail in animals and humans, the central nervous system is divided into the brain, which contains the nerve cells responsible for complex information processing and decision making, and the spinal cord, containing nerve cells for sensing and moving the body. How the cells that make the two parts of the nervous system are formed in an embryo has been a long-standing question in developmental biology.

the formation of the spinal cord is predetermined in cells before they become neural cells

This challenges the textbook view of how the nervous system is formed, which suggested that neural cells progressively transition from brain to spinal cord.

during early development, the activity of a set of proteins, known as CDX transcription factors, establishes which cells can form spinal cord by altering the organisation of the genome in cells.

These proteins not only appear to activate genes needed for the development of spinal neurons but also repress genes specific for brain neurons