mind over matter. new research explains how abstract benefits of exercise-reverse depression in the fight against cognitive decline, could come from a group of key molecules.
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Although our muscles pumping iron, our cells pump something else: the molecules that help maintain a healthy brain. But scientists have struggled to explain the mental well-known advantages of exercise, fight against depression and aging the fight against Alzheimer's and Parkinson's. Now a research team may have finally found a molecular link between a workout and a healthy brain.
Research Many exercise focuses on the parts of our body that do the heavy lifting. Muscle cells increase production of a protein called FNDC5 during a workout. A fragment of this protein, known as irisin name, cut and released into the blood, where it causes the formation of brown fat cells, thought to protect against diseases such as diabetes and obesity. (White fat cells are traditionally the wicked.)
While studying the effects of FNDC5 in muscle, cell biologist Bruce Spiegelman of Harvard Medical School in Boston arrived at some surprising findings: Mice that do not produce a so-called co-activator production FNDC5, known as PGC-1α were hyperactive and had tiny holes in certain parts of their brain. Other studies have shown that FNDC5 and PGC-1α are present in the brain, not only the muscles, and both may play a role in the development of neurons.
Spiegelman and his colleagues suspected that FNDC5 (irisin and created from it) was responsible for the benefits induced by exercise levels of an essential protein called brain-derived neurotrophic factor (BDNF), this which is essential for maintaining healthy neurons and by creating new brain in particular has increased. These functions are essential to ward off the neurological diseases, including Alzheimer's and Parkinson's. And the link between exercise and BDNF is widely accepted. "The phenomenon has been established in easily, the last decade," says neuroscientist Barbara Hempstead at Weill Cornell Medical College in New York, who was not involved in the new work. "It's just, we understand not the mechanism. "
to adjust this mechanism, Spiegelman and colleagues conducted a series of experiments on live mice and mouse brain cells in culture. first, they put the mouse over an endurance training regime of 30 days. They should not force their subjects, because the race is part of the natural feeding behavior of a mouse. "It is more difficult to get them to lift weights" Spiegelman notes. Mice with access to a running wheel ran the equivalent of a 5K every night.
Aside from the physical differences between mice and sedentary wheels trained ones- "they just look a little more like a couch potato," says co-author Christiane Wrann, also from Harvard Medical School, figures luscious-groups of the latter also showed neurological differences. The riders had more FNDC5 in their hippocampus, a brain area responsible for learning and memory.
Using the cells of the developing mouse brain in a dish, the next group showed increased levels of the co-activator PGC- 1α stimulates production FNDC5, which in turn leads to BDNF genes to produce more of the essential protein of neurons forming BDNF. They report these findings online today in Cell Metabolism . Spiegelman said it was surprising that the molecular processes in neurons mirrors what happens in the muscles that we exercise. "What was weird is the same pathway is induced in the brain," he says, "and as you know, with exercise, the brain does not move."
So how is the brain gets the signal to BDNF? Some have hypothesized that neuronal activity during the year (as we coordinate body movements, for example) reflects changes in the brain. But it is also possible that factors outside the brain, such as proteins secreted by muscle cells, are the driving force. to test whether irisin created elsewhere in the body can still lead the production of BDNF in the brain, the group injected a virus into the . mouse blood which causes the liver to produce and secrete high levels of irisin They saw the same effect as in the exercise. increase in BDNF levels in the hippocampus This suggests that irisin might be able to spend the blood-brain barrier, or it regulates another molecule (unknown) therethrough in the brain, said Spiegelman.
Hempstead called the findings "very exciting," and believes that this research is finally beginning to explain how exercise relates to BDNF and other so-called neurotrophins that keep the brain healthy. "I think it answers the question that most of us have put us in our own heads for years."
The liver irisin effect on the brain is a "pretty cool finding and a little surprising," says Pontus Boström, researcher Diabetes at the Karolinska Institute in Sweden. But Boström, who was among the first scientists to identify irisin in muscle tissue, says the work does not answer a fundamental question: To what extent the effects of BDNF-promoting exercise are from reaching the brain irisin from muscle cells via the bloodstream, and how many are irisin created in the brain?
although the authors stress that other important regulatory proteins may play a role in the conduct of BDNF and other brain-nourishing factors, they focus on the benefits of irisin and hope to develop an injectable form of FNDC5 as a potential treatment for neurological diseases and improve brain health with aging.
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