APR 26, 2022 3:14 AM PDT

How Neurons Move as the Brain Forms

WRITTEN BY: Carmen Leitch

If a body is going to function correctly, the cells need to be in the right place. Scientists have learned a lot about how cell migration occurs during development, but the growth of the human brain is still a process we don't know a lot about. Every minute, about 250,000 neurons migrate as the fetal brain develops during a pregnancy. Many of those neurons move a long way from where they began. Researchers have been able to observe that process in animal models. Now, they've been able to study it in humans too, by assessing brain samples from healthy people who died of natural causes. The findings have been reported in Nature.

When a cell divides into daughter cells, a mutation or two might arise among the 3 billion base pairs in the genome, many of which are harmless. Those mutations can be tracked, to follow the trail left by a cell, which can then be read through DNA sequencing.

"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," explained senior study author Joseph Gleeson, MD, the Rady Professor of Neuroscience at UC San Diego School of Medicine.

There are over 30 trillion cells in the human body, most of which contain the entire genome. Gleeson and colleagues have zeroed in on a relatively small number of genetic mutations that appear during early brain development. In this study, those few hundred mutations were tracked in deceased individuals, to reconstruct neural migration, and construct the first map of human brain development.

The researchers began by isolating various types of cells in the brain, and comparing the mutations present in those cell types. When the mutations in genomes of excitatory neurons were compared to mutations in inhibitory neurons, the comparison showed that these cells originated in different brain developmental zones, and later, they come together and mix in the cerebral cortex.

The study also showed that mutations in the left and right sides of the brain are not the same, which suggests that the hemispheres of the brain separate at an earlier developmental time point than we knew.

Image credit: Pixabay

In certain human diseases such as intractable epilepsies, patients spontaneously have seizures, and surgery is necessary to remove epileptic foci, noted Martin W. Breuss, PhD, now an assistant professor at the University of Colorado School of Medicine.

The study authors also noted that the research explains why most foci tend to be exclusive to one side of the brain. The work may help scientists understand other neurological disorders too.

Sources: University of California - San Diego, Nature

About the Author
BS
Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAY 05, 2022
Drug Discovery & Development
Insulin Nasal Spray Improves Cognitive Outcome for Diabetes Patients
MAY 05, 2022
Insulin Nasal Spray Improves Cognitive Outcome for Diabetes Patients
Diabetes is an increasingly common condition that affects at least 1 in 10 U.S adults. Millions more have prediabetes an ...
MAY 09, 2022
Technology
Taking a Break From Social Media Improves Mental Health
MAY 09, 2022
Taking a Break From Social Media Improves Mental Health
Nowadays, it seems like social media usage is a near ubiquitous part of our daily lives. In fact, the Pew Research Cente ...
MAY 11, 2022
Plants & Animals
The Natural World May Help Mental Health, But Studies Lack Diversity
MAY 11, 2022
The Natural World May Help Mental Health, But Studies Lack Diversity
It seems like a no-brainer that the natural world would have a positive effect on our well being, particularly our menta ...
MAY 25, 2022
Neuroscience
Exploring Drug Targets in Neurodegenerative Diseases
MAY 25, 2022
Exploring Drug Targets in Neurodegenerative Diseases
Introduction Life expectancy has increased globally over the last several decades. However, longer life expectancy comes ...
MAY 23, 2022
Neuroscience
Cerebrospinal Fluid From Young Mice Improved Memory in Old Mice
MAY 23, 2022
Cerebrospinal Fluid From Young Mice Improved Memory in Old Mice
As many as one quarter of all adults over the age of 60 experience age-related cognitive decline. This cognitive decline ...
JUL 01, 2022
Neuroscience
Why Do 1 in 15 Physicians Experience Suicidal Ideation?
JUL 01, 2022
Why Do 1 in 15 Physicians Experience Suicidal Ideation?
Researchers have uncovered six overarching themes that contribute to physician suicide. The corresponding study was publ ...
Loading Comments...