JUN 24, 2016 6:08 PM PDT

Running Releases Protein Associated With Improved Memory

WRITTEN BY: Julianne Chiaet
source: Henriette van Praag and Linda Kitabayashi
Countless studies have shown that exercise boosts cognitive function. Yet, the underlying mechanisms behind why this is the case remains uncertain. Researchers recently found that running boosted memory in mice - and they say they've pinpointed the protein behind it. 

The protein cathepsin B is mostly known for being secreted by tumors. It has been implicated in progressing both cancer and Alzheimer’s disease. Thus, the idea that the protein could be behind exercise-induced neuronal growth is controversial. Equally confusing is the number of studies that have found cathepsin B to be neuroprotective.  Neuroscientist Henriette van Praag hypothesizes the contrasting results may be due to different levels of the protein and differing physiological conditions of each participant.

The researchers looked at a wide range of proteins that could potentially "be secreted by muscle tissue and transported to the brain,” van Praag said. “We wanted to cast a wide net.” They soon found that, among the most intriguing candidates, was cathepsin B.  

In a lab dish, the researchers exposed muscle cells to exercise-mimicking compounds. Cathepsin B production significantly increased in the conditioned media.The researchers then looked at mice that spent time on exercise wheels every day for several weeks. They found high levels of cathepsin B in their blood and muscle. When the scientists applied the protein to brain cells, cathepsin B spurred the production of neurogenesis-related molecules.

The researchers then looked at cathepsin B's role in memory. They compared two groups of mice - one group that could produce cathepsin B (normal) and another that couldn't - and looked specifically at the mice's ability to recall memories. The mice were given a daily swim test and prompted to find a platform hidden just below the water's surface. The normal mice were eventually able to recall the location of the platform. The mice lacking in cathepsin B were not able to learn where the platform was. 

Previous to this study, no one had shown cathepsin B’s effect on spatial learning, says van Praag. 

"We also have converging evidence from our study that cathepsin B is upregulated in blood by exercise for three species--mice, Rhesus monkeys, and humans. Moreover, in humans who exercise consistently for four months, better performance on complex recall tasks, such as drawing from memory, is correlated with increased cathepsin B levels,” van Praag said. 

"Overall, the message is that a consistently healthy lifestyle pays off," van Praag says. "People often ask us, how long do you have to exercise; how many hours? The study supports that the more substantial changes occur with the maintenance of a long-term exercise regimen."

The study was published on June 23, 2016, in the journal Cell Metabolism

Sources: Cell Press press release via EurekAlert!, "Running-Induced Systemic Cathepsin B Secretion Is Associated with Memory Function" via Cell Metabolism
About the Author
  • Julianne (@JuliChiaet) covers health and medicine for LabRoots. Her work has been published in The Daily Beast, Scientific American, and MailOnline. While primarily a science journalist, she has also covered culture and Japanese organized crime. She is the New York Board Representative for the Asian American Journalists Association (AAJA). • To read more of her writing, or to send her a message, go to Jchiaet.com
You May Also Like
MAR 18, 2021
Immunology
"Brainwashed" Immune Cells Help Breast Tumors Thrive
MAR 18, 2021
"Brainwashed" Immune Cells Help Breast Tumors Thrive
Immunologists have discovered a mechanism through which immune cells get recruited into breast cancer tumors, and instea ...
MAR 17, 2021
Health & Medicine
CBD Inhibits Brain Changes that Initiate  Alzheimer's: Animal Study
MAR 17, 2021
CBD Inhibits Brain Changes that Initiate Alzheimer's: Animal Study
Cannabidiol, or CBD — the main non-psychoactive ingredient in cannabis — may inhibit some triggers for Alzhe ...
MAR 18, 2021
Neuroscience
Pregnancy Alters the Stress Response in Surprising Ways
MAR 18, 2021
Pregnancy Alters the Stress Response in Surprising Ways
Researchers from Ohio State University have found that the stress response works in unexpected ways in pregnant mice. Th ...
MAR 22, 2021
Microbiology
A Cavity-Forming Germ Gets a Little Help From a Gene Cluster
MAR 22, 2021
A Cavity-Forming Germ Gets a Little Help From a Gene Cluster
There are many microbes that live in the human mouth, and while some are harmless, others like Streptococcus mutans are ...
APR 13, 2021
Immunology
Food-borne Fungus Impedes Gut Healing
APR 13, 2021
Food-borne Fungus Impedes Gut Healing
In a recent study, researchers discovered that a fungus present in cheese, processed meats, beer, and other fermented fo ...
APR 12, 2021
Microbiology
New Lyme Test Can ID The DIsease Early
APR 12, 2021
New Lyme Test Can ID The DIsease Early
Lyme disease is a disease that is caused by four main species of bacteria, including Borrelia burgdorferi, which ar ...
Loading Comments...