Reacción a "The benefits of physical exercise may depend on certain brain changes, according to a study in mice"

The article is interesting and of high quality. The lead author and several co-authors are known for their previous contributions to the study of neural circuits in the brain region known as the hypothalamus, which are involved in the regulation of metabolism and energy expenditure. Specifically, they discovered that neurons known as steroidogenic factor 1 (SF-1) neurons in the ventromedial nucleus of the hypothalamus are involved in the beneficial metabolic responses of skeletal muscle to physical exercise.

The novelty of this study lies in demonstrating that the activation of SF-1 neurons in the hypothalamus progressively modulates muscular and metabolic adaptation to physical exercise. In short, these neurons are activated by physical exercise and, in turn, initiate signaling that induces changes in the gene activation profile of muscle fibers, allowing them to respond better to subsequent training. It is a dynamic process in which neuronal activation progressively increases after each training session, along with the adaptation to physical exertion. If these neurons are not functional, these changes do not occur, and there is no adaptation for future exercise sessions.

Several links in the communication between muscle and SF-1 neurons, and vice versa, remain to be clarified, but the experiments are conclusive.

The authors used genetically modified mice and a wide range of physiological, imaging, and molecular techniques. Physical exercise was performed on treadmills.

This discovery may allow, in the future, for example, the enhancement of training through the activation of SF-1 neuronal circuits, or even without exercise. This would allow people with limited mobility to enjoy the brain benefits of physical activity. We know that physical activity is an essential lifestyle for maintaining and improving cognitive, emotional, and overall brain function.

To date, numerous neuroscience studies have demonstrated the beneficial effects of physical exercise on neurons. Improved respiratory, metabolic, and blood flow function is just one aspect. Factors secreted by skeletal muscle, such as BDNF (brain-derived neurotrophic factor), reach the brain, and the brain itself also secretes this and other factors that impact neuronal plasticity (increased dendritic arborization, more synaptic connections, and increased adult neurogenesis) and neuronal function (more efficient circuits, and improved cognitive and emotional functions). Interestingly, the authors detected an increase in BDNF in the ventromedial nucleus of the hypothalamus in mice after physical exercise.

These studies by the authors open a new perspective on physical exercise, suggesting that the brain controls some of the adaptive changes that occur in muscle. And it's not surprising that the signals originate in the hypothalamus, a center that regulates peripheral organs through the autonomic nervous system and is involved in energy status and vital activities such as food intake, sleep, and sexual desire.

We must consider that inhibiting these circuits doesn't completely eliminate adaptation to physical exercise, but rather reduces the response, which reaches its peak sooner and is weaker, at least in mice. Genetic predisposition is a crucial factor in the performance of elite athletes. So too is the mental strength to control exertion in endurance sports. Investigating whether the state of these neurons is involved in athletic success would confirm the relevance of this work.