The making of a human brain remains a mostly mysterious process that races from an embryonic neural tube to more than 100 billion interconnected neurons in the brain of a newborn. To achieve this marvel of biological engineering, the developing fetal brain must grow, on average, at a rate of roughly 250,000 nerve cells per minute throughout the course of a pregnancy.
These nerve cells are often generated far from where they will eventually reside and function in the new brain, a migration that, while much investigated in animal models using chemical or biological tracers, has never been studied directly in humans. Until now.
In a new paper, published in Nature, scientists describe novel methods for inferring the movement of human brain cells during fetal development by studying healthy adult individuals who have recently passed away from natural causes.
“Every time a cell divides into two daughter cells, by chance, there arise one or more new mutations, which leave a trail of breadcrumbs that can be read out by modern DNA sequencers,” said senior author.
“By developing methods to read these mutations across the brain, we are able to reveal key insights into how the human brain forms, in comparison with other species.”
Although there are 3 billion DNA bases — and more than 30 trillion cells in the human body — Gleeson and colleagues focused their efforts on just a few hundred DNA mutations that likely arose during the first few cell divisions after fertilization of the embryo or during early development of the brain. By tracking these mutations throughout the brain in deceased individuals, they were able to reconstruct development of the human brain for the first time.
To understand the type of cells displaying these breadcrumb mutations, they developed methods to isolate each of the major cell types in the brain. For instance, by profiling the mutations in excitatory neurons compared with inhibitory neurons, they confirmed the long-held suspicion that these two cell types are generated in different germinal zones of the brain, and then later mix together in the cerebral cortex, the outermost layer of the organ.
However, they also discovered that the mutations found in the left and right sides of the brain were different from one another, suggesting that — at least in humans — the two cerebral hemispheres separate during development much earlier than previously suspected.
The results have implications for certain human diseases, like intractable epilepsies, where patients show spontaneous convulsive seizures and require surgery to remove an epileptic brain focus, said the lead author.
https://www.nature.com/articles/s41586-022-04602-7
http://sciencemission.com/site/index.php?page=news&type=view&id=publications%2Fsomatic-mosaicism-in&filter=22
Tracking the cellular migration of developing fetal brains
- 1,438 views
- Added
Latest News
Role of fat in rare neurolo…
By newseditor
Posted 23 Apr
How protein synthesis in de…
By newseditor
Posted 22 Apr
Atlas of mRNA variants in d…
By newseditor
Posted 22 Apr
Mapping microbiome in metas…
By newseditor
Posted 22 Apr
Full-length mRNA packaged i…
By newseditor
Posted 22 Apr
Other Top Stories
Human brain compensation in hemispherectomy!
Read more
New players in the fertilization may help to address infertility
Read more
Expert's brain has selective sub networks!
Read more
Inflammation drives tau and amyloid pathologies!
Read more
How the brain decides to punish or not
Read more
Protocols
A programmable targeted pro…
By newseditor
Posted 23 Apr
MemPrep, a new technology f…
By newseditor
Posted 08 Apr
A tangible method to assess…
By newseditor
Posted 08 Apr
Stem cell-derived vessels-o…
By newseditor
Posted 06 Apr
Single-cell biclustering fo…
By newseditor
Posted 01 Apr
Publications
Long-term neuropsychologica…
By newseditor
Posted 23 Apr
Neuronal activity rapidly r…
By newseditor
Posted 22 Apr
A perspective on muscle phe…
By newseditor
Posted 22 Apr
Foxp1 suppresses cortical a…
By newseditor
Posted 22 Apr
Single-cell long-read seque…
By newseditor
Posted 22 Apr
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar