New cutting-edge research shows that the health of your nervous system depends as much on information sent from the body’s large leg muscles to the brain as it does on how much information is sent from the brain to the muscles.
In a new study, published in Frontiers in Neuroscience, researchers have literally changed the way nervous system medicine is approached. This new perspective gives doctors clues as to why patients suffering from conditions like multiple sclerosis, motor neuron disease, spinal muscular atrophy and other neurological diseases suffer from a rapid decline in health when their movement becomes limited.
Dr. Raffaella Adami from the Università degli Studi di Milano, Italy says, "Our study supports the notion that people who are unable to do load-bearing exercises—such as patients who are bed-ridden, or even astronauts on extended travel—not only lose muscle mass, but their body chemistry is altered at the cellular level and even their nervous system is adversely impacted”.
The study used mice to determine the effects of limited motion on the brain. They did this by restricting the mice from using their hind legs but allowed them full use of their front legs for 28 days.
At the end of the trial the researchers examined a specific region of the brain known as the sub-ventricular zone. This area maintains nerve cell health in a variety of mammals. It’s also the area where neural stem cells produce new neurons.
During the study, they continued normal grooming and didn’t appear to suffer from any stress, but by limiting physical activity, the number of neural stem cells in the sub-ventricular zone was reduced by 70 percent when compared to a control group that was allowed full use of their limbs.
In addition, neuron and other supporting cells weren’t able to fully mature in the group where exercise was severely limited.
The research indicates that the legs, especially when used for weight bearing exercise play an important role in sending electrical impulses to the brain that help in maintaining the health of neural cells, vital for maintaining the brain and nervous system.
Reducing the total volume of exercise, makes it hard for the body to produce new, healthy nerve cells.
"It is no accident that we are meant to be active: to walk, run, crouch to sit, and use our leg muscles to lift things," says Adami. "Neurological health is not a one-way street with the brain telling the muscles 'lift,' 'walk,' and so on."
The researchers were able to learn even more by analyzing specific nerve cells. What they found was that when exercise is limited, it reduces the amount of available oxygen to the body. This in turn, creates an anaerobic environment that changes the metabolism.
The reduction in exercise also appeared to have an effect on two important genes, one in particular called CDK5Rap1 is crucial for the health of the mitochondria – the part of the cell that produces energy.
The results obtained in this study help shed some light on a few important health issues, things like cardio-vascular impacts secondary to a sedentary lifestyle and more severe neurological diseases like spinal muscular atrophy, motor neuron disease and multiple sclerosis.
The study’s co-author, also from the Università degli Studi di Milano, Dr. Daniele Bottai said, "I have been interested in neurological diseases since 2004, the question I asked myself was: is the outcome of these diseases due exclusively to the lesions that form on the spinal cord in the case of spinal cord injury and genetic mutation in the case of SMA, or is the lower capacity for movement the critical factor that exacerbates the disease?"
One thing this study does do very well is to demonstrate just how vital movement is on brain and nervous system health.
This is particularly important in space missions where astronauts are exposed to zero gravity for months and years on end. The importance of gravity and weight-bearing exercise can not be over-emphasized.
"One could say our health is grounded on Earth in ways we are just beginning to understand," concludes Bottai.