Exercise can directly improve brain health by promoting hippocampal neuronal development, with astrocytes playing a key role in mediating the effects. This research could lead to exercise-based treatments for cognitive disorders such as Alzheimer’s disease.
Studying chemical signals from contracting muscle cells points to ways of improving brain health with exercise.
Beckman researchers studied how chemical signals from contracting muscles promote healthy brains. Their findings reveal how these signals help grow and regulate new brain networks while also pointing toward ways of improving brain health through exercise.
Physical activity is frequently cited as a means of improving physical and mental health. Researchers at the Beckman Institute for Advanced Science and Technology have shown that it may also improve brain health more directly. They studied how the chemical signals released by exercising muscles promote neuronal development in the brain.
Their work was published in the journal Neuroscience.
When muscles contract during exercise, like a bicep working to lift a heavy weight, they release a variety of compounds into the bloodstream. These compounds can travel to different parts of the body, including the brain. The researchers were particularly interested in how exercise could benefit a particular part of the brain called the hippocampus.
“The hippocampus is a crucial area for learning and memory, and therefore cognitive health,” said Ki Yun Lee, a Ph.D. student in mechanical science and engineering at the University of Illinois Urbana-Champaign and the study’s lead author. Understanding how exercise benefits the hippocampus could therefore lead to exercise-based treatments for a variety of conditions including <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
Alzheimer’s
Alzheimer’s disease is a disease that attacks the brain, causing a decline in mental ability that worsens over time. It is the most common form of dementia and accounts for 60 to 80 percent of dementia cases. There is no current cure for Alzheimer’s disease, but there are medications that can help ease the symptoms.
Hippocampal neurons (yellow) surrounded by astrocytes (green) in a cell culture from the study. Image provided by the authors. Credit: Image provided by the study authors: Taher Saif, Justin Rhodes, and Ki Yun Lee
To isolate the chemicals released by contracting muscles and test them on hippocampal neurons, the researchers collected small muscle cell samples from mice and grew them in cell culture dishes in the lab. When the muscle cells matured, they began to contract on their own, releasing their chemical signals into the cell culture.
The research team added the culture, which now contained the chemical signals from the mature muscle cells, to another culture containing hippocampal neurons and other support cells known as astrocytes. Using several measures, including immunofluorescent and calcium imaging to track cell growth and multi-electrode arrays to record neuronal electrical activity, they examined how exposure to these chemical signals affected the hippocampal cells.
The results were striking. Exposure to the chemical signals from contracting muscle cells caused hippocampal neurons to generate larger and more frequent electrical signals — a sign of robust growth and health. Within a few days, the neurons started firing these electrical signals more synchronously, suggesting that the neurons were forming a more mature network together and mimicking the organization of neurons in the brain.
However, the researchers still had questions about how these chemical signals led to growth and development of hippocampal neurons. To uncover more of the pathway linking exercise to better brain health, they next focused on the role of astrocytes in mediating this relationship.
“Astrocytes are the first responders in the brain before the compounds from muscles reach the neurons,” Lee said. Perhaps, then, they played a role in helping neurons respond to these signals.
The researchers found that removing astrocytes from the cell cultures caused the neurons to fire even more electrical signals, suggesting that without the astrocytes, the neurons continued to grow — perhaps to a point where they might become unmanageable.
“Astrocytes play a critical role in mediating the effects of exercise,” Lee said. “By regulating neuronal activity and preventing hyperexcitability of neurons, astrocytes contribute to the balance necessary for optimal brain function.”
Understanding the chemical pathway between muscle contraction and the growth and regulation of hippocampal neurons is just the first step in understanding how exercise helps improve brain health.
“Ultimately, our research may contribute to the development of more effective exercise regimens for cognitive disorders such as Alzheimer’s disease,” Lee said.
Reference: “Astrocyte-mediated Transduction of Muscle Fiber Contractions Synchronizes Hippocampal Neuronal Network Development” by Ki Yun Lee, Justin S. Rhodes and M. Taher A. Saif, 2 February 2023, Neuroscience. DOI: 10.1016/j.neuroscience.2023.01.028
In addition to Lee, the team also included Beckman faculty members Justin Rhodes, a professor of psychology; and Taher Saif, a professor of mechanical science and engineering and bioengineering.
The National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research. Founded in 1887, it is a part of the U.S. Department of Health and Human Services. The NIH conducts its own scientific research through its Intramural Research Program (IRP) and provides major biomedical research funding to non-NIH research facilities through its Extramural Research Program. With 27 different institutes and centers under its umbrella, the NIH covers a broad spectrum of health-related research, including specific diseases, population health, clinical research, and fundamental biological processes. Its mission is to seek fundamental knowledge about the nature and behavior of living systems and the application of that knowledge to enhance health, lengthen life, and reduce illness and disability.
The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.
It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.
Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”
Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.
Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.
A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.
On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.
Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”
But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”
“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.
Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.
Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.
Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.
“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.
“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”
This report by The Canadian Press was first published Sept. 13, 2024.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.
The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.
Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.
“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”
The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.
A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.
Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.
“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.
Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.
The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.
“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.
This report by The Canadian Press was first published Sept. 11, 2024.
ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.
Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.
Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.
Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.
The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.
“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.
Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.
Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.
Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.
A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.
This report by The Canadian Press was first published Sept. 10, 2024.
