Monday, April 6, 2015

Inactivity Changes the Brain


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.

 
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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.








Sources:

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



17 comments:

  1. Teenagers today spend hours on hours laying on the couch watching TV, Netflix, going on their computer and what not. It is obvious that laying down doing nothing is worse than going outside and exercising, but I did not know that it would seriously effect your brain. Being inactive for long periods of time can cause the brain to become more sensitive to stimuli, which could lead to overstimulation. This would increase blood pressure and cause there to be an increase in the chance of getting a heart disease. Yes exercising is good for a person's health, but it is also good for the brain which is something I was unaware of.

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  2. I was surprised by the findings of this study as I already knew that exercise was good for the brain, but did not even realize or think about what not doing any exercise would do to my brain and my health. Specifically, heart disease is a serious issue that has in the past been related to sedentary lifestyles and now seeing the link proven scientifically is even more alarming. In addition, the brain needing stimuli raises the important issue of keeping children occupied in a productive way, as opposed to sticking them in front of a TV.

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  3. I think it would be interesting as well to see the effects not only that inactivity have on the brain, but also some of the activities associated with inactivity. People often say that TV, the computer, and other screens "rot your brain", so I would be interested to see the actual medical/ scientific impact of screens on the brain, and also is any amount of screens unhealthy, or how much is too much?

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  4. It is interesting to see how the effects of a sedentary lifestyle could also have detrimental impacts on your health, but on your brain as well. It would be interesting to see if leading a sedentary lifestyle could also affect other parts of the brain and how it could possibly link it with other diseases such as obesity.

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  5. Yes I agree with Hunter that it would be interesting to determine the impact of screens on the brain, especially in our technology-obsessed world. The authors of this paper suggested that the increase in sensitively of the neurons was due to a lack of input so I would be curious to see what the constant input of a screen would do to this sensitivity.

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  6. I found it interesting that inactivity can lead to overstimulation, not understimulation. I can see a connection here between this idea and the idea of upregulation of receptors when they aren't stimulated enough.

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  7. This is such an interesting post!! I have heard that obesity leads to neuronal disorders in the long term. I wonder if there is a connection between inactivity resulting in obesity, which is leading to unhealthy stimuli.

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  8. Did the study provide a reason for testing the rostral ventrolateral medulla? Do you think other parts of the brain would respond differently to the lack of exercise? I would assume they would respond the same, but it would be interesting to know why they chose to test that specific part of the brain.

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  9. Did the study provide a reason for testing the rostral ventrolateral medulla? Do you think other parts of the brain would respond differently to the lack of exercise? I would assume they would respond the same, but it would be interesting to know why they chose to test that specific part of the brain.

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  10. Meredith brings up the point that I noticed when reading through the article. No doubt a sedentary lifestyle would not produce positive effects for the brain, but what are the effects on other parts of the brain of inactivity? Or did the scientists in the study find that the differences lay mainly in the rostal ventrolateral medulla, and showed a connection to the increased blood pressure and rates of cardiovascular disease for those with a sedentary lifestyle.
    It is also interesting to perhaps postulate the effects of inactivity on our brain's processing abilities, and perhaps the more abstract concepts of thinking and our minds. Many of the "great" minds of the past were of people who probably had more sedentary lifestyles than others at the time, though perhaps their activity level was still higher than what we consider sedentary. Nevertheless these people often engaged in less activity. I wonder if their activity level did have a detrimental effect on their brain's functioning, and what may have been the case if they had been more active.

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  11. This is a very interesting article, and I think that it is very applicable to us as college students who sit in the library for hours. I also think that the comments from Hunter and Jodi are interesting; I'm sure that looking in to the different subgroups that could be made could yield some informative results. It would have been interesting to see if the age of the rats had anything to do with the degree of change observed in the brains of each rat.

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  12. This is a very interesting article, and I think that it is very applicable to us as college students who sit in the library for hours. I also think that the comments from Hunter and Jodi are interesting; I'm sure that looking in to the different subgroups that could be made could yield some informative results. It would have been interesting to see if the age of the rats had anything to do with the degree of change observed in the brains of each rat.

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  14. I enjoyed this post very much. It did raise some questions for me though mainly surrounding the level of activity in the rats. It would be interesting to see if it is just the lack of activity that causes RVLM issues or if increased levels of activity could improve the RVLM in rats. This could mean that even more activity is even better for you which would be interesting to test.

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  15. It certainly makes sense that being inactive and taking too much time on the computer would have some sort of negative impact on the brain. However, I'd like to see some research done on other parts of the brain, not the RLMV. Did inactivity cause lack of neurons directly, or did the reduced exercise lead to cardiovascular problems, which then led to issues with the RLMV?

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  16. I agree with Jack, I felt that this study really over simplified the effects of exercise and inactivity on the brain. Could it be possible that the rats that were give a wheel to exercise on have a have increased activity in neurons because of the unnatural type of exercise they are doing in a lab setting? I was thinking of adding some sort of control where rats were given access to larger cages where they have more space to run and climb in a natural way. I think it is safe to assume the lack of activity might have had some sort of effect on the brain, but because there was no "natural" activity to compare it to, they are comparing unnatural exercise with zero exercise, which leaves them with no control to compare the two conditions to. It is hard in the experiment to determine what effected what because of the experimental method.

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  17. College students lead fairly sedentary lifestyles considering we spend a significant amount of time in class and in the library or studying. As hard as we try, we still spend a large portion of our time sitting. This is interesting because this post suggests that we may be hurting our brain, while at the same time studying in order to learn more. My question is whether age is a factor in all of this? If younger people have sedentary lifestyles (like a college student, for instance), will it have the same effect on the brain as when an elderly person spends all their time sitting in front of the TV?

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