FEB 09, 2021 12:26 PM PST

Brain Cells Called Astrocytes Linked to Depression

WRITTEN BY: Carmen Leitch

Depression is thought to affect at least 264 million people of all ages worldwide, according to the World Health Organization (and this article discusses suicide; if you or someone you know is in crisis, contact SAMHSA’s National Helpline at 1-800-662-HELP (4357)). While there are some treatment options, they don't work for everyone, in part because we don't understand exactly how depression is caused at the biological level. New work has suggested that a type of cell in the brain called astrocytes, long thought to act mainly as a supportive network for neurons, are involved in the physiology of depression.

Image credit: Modified from Pixy

Scientists assessed the post-mortem brains of adults that had committed suicide, and compared them to the brains of people that did not have psychiatric problems and had died suddenly in other ways. Reporting in Frontiers in Psychiatry, the researchers identified differences in the cellular composition of the brains of depressed and non-depressed individuals.

"We found a reduced number of astrocytes, highlighted by staining the protein vimentin, in many regions of the brain in depressed adults," revealed the senior study author Naguib Mechawar, a Professor at the Department of Psychiatry, McGill University. "These star-shaped cells are important because they support the optimal function of brain neurons. Our findings confirm and extend previous research implicating astrocytes in the pathology of depression."

Clinical depression is defined by persistent feelings of sadness and a loss of interest or pleasure from once-enjoyable activities; it can lead to other emotional and physical problems.

"We analyzed the astrocytes in the brain by staining specific proteins found in their structure -- vimentin and GFAP. Vimentin staining has not been used before in this context, but it provides a clear, complete, and unprecedented view of the entire microscopic structure of these cells," explained Liam O'Leary, who was part of this work during his doctoral studies at McGill. "Using a microscope, we counted the number of astrocytes in cross-sections of the brain, enabling us to estimate how many were in each region. We also analyzed the 3D structure of over three hundred individual astrocytes for any differences."

 Though there were not as many astrocytes, the structure of astrocytes in depressed individuals was very similar to the ones in healthy people.

"This research indicates that depression may be linked to the cellular composition of the brain. The promising news is that unlike neurons, the adult human brain continually produces many new astrocytes. Finding ways that strengthen these natural brain functions may improve symptoms in depressed individuals," said Mechawar.

This work could help scientists create new treatment options, but first, the findings will have to be confirmed in larger groups of people and should include female patients, which this study did not.

"Our study provides a strong rationale for developing drugs that counteract the apparent loss of astrocytes in depression," says O'Leary. "No antidepressants have yet been developed to target these cells directly, although the leading theory for the rapid antidepressant action of ketamine, a relatively new treatment option, is that it corrects for astrocyte abnormality."

"While this study is the most comprehensive so far, it was only conducted with samples from male patients. We want to widen this study to investigate samples from female patients since it is now known that the neurobiology of depression differs quite significantly between men and women," added Mechawar.

Sources: AAAS/Eurekalert! via Frontiers, Frontiers in Psychiatry

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
AUG 25, 2022
Cell & Molecular Biology
From sample collection straight to RT-qPCR
AUG 25, 2022
From sample collection straight to RT-qPCR
Skip the nucleic acid purification step in your cancer detection workflow. Learn more about how Thermo Fisher Scientific ...
AUG 14, 2022
Genetics & Genomics
Restoring Cell Function with Light
AUG 14, 2022
Restoring Cell Function with Light
Optogenetics is a technique that has been in development for several years, and aims to combine optics and genetics to u ...
SEP 09, 2022
Immunology
Antibodies are Sometimes Made with 'Stolen' DNA
SEP 09, 2022
Antibodies are Sometimes Made with 'Stolen' DNA
The human immune system must respond to a diverse array of infectious agents and harmful invaders throughout our lifetim ...
SEP 19, 2022
Genetics & Genomics
Some Gene Variants May Encourage Active or Sedentary Lifestyles
SEP 19, 2022
Some Gene Variants May Encourage Active or Sedentary Lifestyles
There is still a lot of debate about how much a person's genes influence their behavior. Twin studies are one way to hel ...
SEP 21, 2022
Immunology
Calorie Reduction Lowers Levels of Aging-Linked Proteins
SEP 21, 2022
Calorie Reduction Lowers Levels of Aging-Linked Proteins
A variety of studies have suggested that diets that restrict or reduce caloric intake can lengthen lifespan. Now, resear ...
SEP 23, 2022
Microbiology
Heme-Loving Plant Peptide Could Have Many Applications
SEP 23, 2022
Heme-Loving Plant Peptide Could Have Many Applications
Symbiotic relationships enable organisms to use one another, usually to the advantage of both. Legumes can live in symbi ...
Loading Comments...