Have you ever wondered if spending a weekend binge-watching tv shows on Netflix is really that bad for your health? Researchers are saying that there could be actual detrimental effects in neurons as a result of leading a sedentary life.
A recent study by Mischel et al, 2014, focuses on the effects of a sedentary lifestyle on the brain. While many studies in the past research have shown that exercise can change the brain with growth of new neurons and synapses, this study sought to discover if inactivity could change the brain in the opposite way. Scientists at Wayne State University School of Medicine compared the brains of rats allowed access to a running wheel to those of rats denied a means to exercise.
The part of the brain that Mischel and colleagues studied was the rostral ventrolateral medulla (RVLM), in which they injected a dye. The RVLM has neurons that are associated with the control of sympathetic nerves and blood pressure. After 12 weeks of either being active or sedentary, the brains of the rats were compared. It turned out that there were noticeable differences in the shape of some of the neurons in that region of the brain between the active rats and the inactive rats. The scientists found that the shape of the neurons of the active rats remained similar after the 12 weeks of activity. On the other hand, the inactive rats had neurons with many more branches than before, making them more sensitive to stimuli. The researchers suggest that this over sensitivity will lead to an overstimulation of the sympathetic nervous system, which could increase blood pressure and contribute to heart disease.
|RVLM Neuron of Active Rat|
This study is especially interesting for neurophysiologists because it is another example of how the neurons of the brain can display plasticity. This study furthers develops our understanding of neuronal plasticity by showing that not only can new neurons form, but the shape of neurons, specifically the dendrites, can change as well. The researchers also emphasize that not only can stimuli change the brain, but so can a lack of stimuli. It would be interesting to see if these effects on rats carry over to the human brain.
|RVLM Neuron of Sedentary Rat|
Discovering that inactivity could potentially lead to an overstimulation in the sympathetic nervous system is another reminder of how important being active can be. Exercise is not only about improving the body’s health, but it is also about giving the brain the proper healthy stimuli it needs.
Banalities. June 10, 2007. Digital Image. Flickr. Yahoo! Inc. Web. 6 April, 2015. <https://farm2.staticflickr.com/1157/542629880_7285e8421f_o.jpg>
Mischel NA, Llewellyn-Smith IJ, and Mueller PJ (2014) Physical (In)Activity-Dependent Structural Plasticity in Bulbospinal Catecholaminergic Neurons of Rat Rostral Ventrolateral Medulla. The Journal of Comparative Neurology. 522:499–513