Contracting and exercising muscles may help nerves recover and grow after nerve damage, a new animal study has found. During workouts, muscles release chemicals called myokines. Researchers at the Massachusetts Institute of Technology (MIT) found that motor neurons exposed to myokines grew four times more than those not exposed.
Stretching the nerves to mimic the physical force of muscle contraction led to comparable growth results. Motor neurons are nerves that help the body move. They differ from sensory neurons, which detect our senses, and cortical neurons, responsible for cognition.
The researchers said the study’s findings may be promising for neurodegenerative diseases that affect motor neurons, like amyotrophic lateral sclerosis (ALS), or Lou Gehrig’s disease. Myokines are molecules that communicate with cells and tissues throughout the body, influencing various biological processes. Although muscles primarily produce myokines during exercise, other cells also release these molecules during physical activity.
Neurons exposed to the “exercise” solution showed significant increases across all measures of nerve growth: They grew over four times longer, had single projections that grew 1.5 times farther, and covered 2.9 times more area than controls.
Some lab-grown muscles also twitched spontaneously, a common behavior in muscle cultures. Researchers found that myokines from these twitching muscles also promoted neuron growth, though the exercised-muscle solution .
