Researchers at Karolinska Institute have charted a highly detailed molecular atlas of the foetal development of the brain.
The study, published in Nature, made use of single-cell technology which was performed on mice. In this way, researchers have identified almost 800 different cells that are active during foetal development – far more than previously known.
“Brain development is well described and the main cell types are known. What is new about our atlas is the high resolution and detail,” said Sten Linnarsson, head of research and professor at the Department of Medical Biochemistry and Biophysics, Karolinska Institutet.
In their work, the researchers followed the brain development of the mice from day seven, when the brain is just forming, to the end of pregnancy on day 18.
Using single-cell technology, they were able to identify the detailed composition of the brain during foetal development: what cell types exist, how many cells of each type, and how this changes at the various stages of development.
The researchers also studied gene activity in each individual cell, classifying cells according to these activity patterns.
Creating a molecular atlas
The result is a molecular atlas that accurately illustrates how all cells in the brain develop from the early embryo. The atlas shows, for example, the way early neural stem cells first increase and then decrease in number, being replaced by transitional forms in several waves that eventually mature into ready-made neurons.
The researchers also demonstrated how early stem cell lines branch much like a family tree, giving rise to several different types of mature cells. The next step is mapping out atlases of the human brain, both in adults and during foetal development.
“Atlases like this are of great importance for research into the brain, both to understand brain function and its diseases. Cells are the body’s basic building blocks and the body’s diseases are always expressed in specific cells. Genes that cause serious diseases are found in all of the body’s cells, but they cause disease only in specific cells in the brain,” said Prof Linnarsson.
Source: Karolinska Institute
Journal information: “Molecular Architecture of the Developing Mouse Brain”, Gioele La Manno, et al. Nature, online 28 July 2021, doi:10.1038/s41586-021-03775-x.
