The study sheds light on the reason
why patients with neurological diseases like motor neuron disease, multiple sclerosis
, and spinal muscular atrophy
often rapidly decline after their movement becomes limited.
‘Neurological health depends to a large extent on exercising the muscles of the leg, says a study that shows that restricting leg movement could lead to advancing neurological disorders.’
"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," says Dr. Raffaella Adami from the
Universitā degli Studi di Milano, Italy.
- How does leg movement affect Brain Health?
Researchers conducted experiments with
two sets of mice - the mice in set one were allowed to use only their front
legs and were restricted from using their hind legs for a period of 28 days.
The mice in set two were the control mice which were allowed to roam. During
the trial, the mice in both sets continued to eat and groom normally and did
not exhibit stress.
The researchers also studied
individual cells to see the impact of reduced exercise at a cellular level.
Results at the end of
- There was a decrease
in the number of neural stem cells by 70 percent in the sub-ventricular zone in
the test mice, compared to the control group mice. The sub-ventricular area
is where the stem cells produce new
nerve cells or neurons and is a region important in many mammals for
maintaining nerve cell health.
- Limiting physical activity caused neurons and specialized cells called oligodendrocytes that support and
insulate nerve cells to mature incompletely.
- When analyzing individual cells, the researchers found
that cutting down on exercise reduced
the amount of oxygen in the body, which in turn could alter metabolism. It
also impacted two genes. One of the
genes called CDK5Rap1 that was affected
is very important for mitochondrial health. The mitochondria as we all know
is the powerhouse of the cells that are essential for producing and releasing
the energy needed by the body.
Significance of the results
The study shows that exercising the
legs, especially in weight-bearing exercise
, sends messages
across to the brain to produce healthy neural cells. Nerve cells are the
building blocks of the brain and nervous system and allow us to handle stress
and adapt to challenge in our lives.
Hence, reducing exercise could cause
an opposite effect and make it difficult for the body to produce new nerve
"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."
It now seems clear that leg movement
has a critical role to play, and the lack of it could have several health
impacts - some known ones like cardio-vascular impacts as a result of sedentary
lifestyles, to some others that are yet to be studied, like health issues that
occur due to lack of gravity and load-bearing exercise when astronauts are sent
into space for months or even years, say the researchers.
We can conclude by saying that reduced exercise is a critical factor that
exacerbates neurological diseases
and the current study fundamentally
alters brain and nervous system medicine.
"One could say our health is
grounded on Earth in ways we are just beginning to understand," concludes
co-author Dr. Daniele Bottai, also from the Universitā degli Studi di Milano.
Neurological disorders affect the central and
peripheral nervous system, which comprises the brain, spinal cord, cranial
nerves, peripheral nerves, nerve roots, autonomic nervous system, neuromuscular
junction, and muscles.
These disorders include epilepsy, Alzheimer disease
and other dementias, stroke, migraine,
multiple sclerosis, Parkinson's disease, neuroinfections, brain tumors, and
traumatic disorders of the nervous system due to head trauma. Many bacterial,
viral, fungal, and parasitic infections can affect the nervous system.
The global burden of neurological disorders is
high. Globally, more than 6 million people die due to stroke each year, more
than 50 million people have epilepsy
, an estimated 47.5 million
people live with dementia (Alzheimer's disease contributes to 60-70% of cases),
and the prevalence of migraine
is more than 10% worldwide.
- Leg exercise is critical to brain and nervous system health - (https://www.eurekalert.org/emb_releases/2018-05/f-lei051718.php)
- What are neurological disorders? - (http://www.who.int/features/qa/55/en/)