summary: Researchers have found a significant link between exercise, muscle function, and brain health. Their research revealed that the nerves that activate muscles during exercise also trigger the release of molecules that enhance brain function.
They found that stimulating these nerves with glutamate caused the innervated muscles to produce more brain-activating hormones and extracellular vesicles. This study highlights the importance of maintaining neuromuscular health to support brain and overall organ function, especially as we age.
Important facts:
- Neuronal influence on muscle secretion: Muscles that are innervated by neurons produce more substances that promote brain health compared to muscles that are not innervated.
- Effects of glutamate on muscle activation: Glutamate stimulation increases the secretion of beneficial hormones such as irisin and promotes the release of extracellular vesicles containing microRNAs that support neurodevelopment.
- Aging and its impact on neuromuscular health: This study highlights the important role of neuron-muscle interactions in maintaining cognitive function, and is particularly relevant for older adults and people with neuromuscular disorders.
sauce: University of Illinois
Exercise prompts muscles to release molecular cargo and strengthens brain cell function and connectivity, a process that is not well understood. A new study from the University of Illinois at Urbana-Champaign has found that the nerves that tell muscles to move also trigger the release of factors that activate the brain.
“Molecules released by the muscles enter the bloodstream and then reach the brain, creating what is called crosstalk between the muscles and the brain. But the muscles themselves are highly innervated.
“So we thought about how neurons influence muscle activity and, in turn, how they influence communication between muscles and the brain,” said the leader of the study published in Gong Hyun-jun, a professor of chemical and biomolecular engineering, said: Proceedings of the National Academy of Sciences.
“As we age, we lose these neurons from our muscles. Some people also lose these neurons due to disease or injury. So we need to understand their role and how the nerves to the muscles affect the brain. “Understanding what to give is important for older adults and patients with neuromuscular injuries or diseases,” he said.
Exercise research has found that muscles secrete hormones and extracellular vesicles (small packages that carry molecules between cells) that contain small pieces of RNA that strengthen connections, signaling, and communication between brain cells. .
But while much attention has been paid to the function of muscle-derived factors, the role of nerves that innervate muscles is poorly understood, said graduate student Kai-Yu Huang, lead author of the study. Stated.
To fill this gap, the researchers compared two muscle tissue models, one with neuronal innervation and one without. The researchers found that innervated muscles produce more molecules that boost brain neuron activity and regulate muscle development than non-innervated muscles.
Next, the researchers stimulated the nerves with the neurotransmitter glutamate. They found that expression of genes important for regulating secretion was higher in innervated muscles.
Similarly, levels of irisin, a hormone associated with the beneficial effects of exercise, were increased and more extracellular vesicles were released than in simple muscle.
“When we analyzed the cargo carried within the vesicles, we found a greater diversity of microRNAs associated with effects on neurodevelopment,” Huang said.
“These findings highlight the importance of neuronal innervation. As we age, the nerve supply to our muscles is lost, and our muscles begin to break down and lose function. And somehow, this… can lead to further organ dysfunction. Therefore, understanding how to regulate or maintain muscle secretory behavior is critical.”
Next, the researchers looked more closely at the mechanisms at the junction where neurons meet muscle cells, and learned how nerve impulses stimulate muscles and how they affect the production of brain activators. We plan to elucidate whether it affects only the release of brain-activating factors, which is an important distinction among brain-activating factors. A possible treatment for people who have lost nerves or muscles.
They would also like to consider using tissue models as a platform to effectively generate factors. Ultimately, I would like to elucidate the overall structure of the brain-nerve-muscle loop and how to maintain it.
“Our individual organs talk to each other. The brain tells the nerves to stimulate the muscles, and the muscles release molecules that are beneficial to brain function,” Conn said.
“This highlights the importance of exercise. Exercise creates a stronger interface between motor neurons and muscles, and the nerves that signal the muscles release molecules and extracellular vesicles that are beneficial to the brain. I know that.
“This allowed us to look at the benefits of exercise that focuses on promoting muscle connections, rather than simply increasing muscle mass and strength.”
About this exercise and neuroscience research news
author: liz ahlberg touchstone
sauce: University of Illinois
contact: Liz Ahlberg Touchstone – University of Illinois
image: Image credited to Neuroscience News
Original research: Closed access.
“Innervation regulates the secretion of neurotrophic myokines and exosomes from skeletal muscle” written by Kai-Yu Huang et al. PNAS
abstract
Innervation regulates the secretion of neurotrophic myokines and exosomes from skeletal muscle
Myokines and exosomes derived from skeletal muscle have been shown to play an important role in maintaining brain homeostasis.
Although it has been reported that exercise enhances muscle secretion, little is known about the influence of innervation and activity on the yield and molecular composition of biologically active molecules from muscle.
Because neuromuscular diseases and disorders associated with denervation affect muscle metabolism, we hypothesize that innervation and firing may play a pivotal role in regulating skeletal muscle secretory activity.
We tested this hypothesis using an artificial neuromuscular tissue model consisting of skeletal muscle innervated by motor neurons.
Innervated muscles contain mRNAs encoding neurotrophic myokines such as interleukin-6, brain-derived neurotrophic factor, FDNC5, and peroxisome proliferator-activated receptor gamma coactivator, an important regulator of muscle metabolism. 1α mRNA expression was increased.
Upon glutamate stimulation, innervated muscles secreted higher levels of irisin and exosomes containing more diverse neurotrophic microRNAs than muscles without neurons.
As a result, biological factors secreted by innervated muscles enhanced branching, axonal transport, and ultimately spontaneous network activity of primary hippocampal neurons in vitro.
Altogether, these results reveal the importance of neural innervation in regulating muscle-derived factors that promote neural function and show that artificial neuromuscular tissue models hold great promise as a platform for producing neurotrophic molecules. This suggests that
