NRSC 4132 Blog

You just finished your 30 mile bike ride or just finished that triathlon you always wanted in great time.. Now your exhaustedâ?¦ now what why canâ??t you finish your thought? Is it possible that the muscle fatigued you experiences can impacted you mentally? Studies indicate that the mental and actual movements share overlapping neural substrates (Jeannerod, 2001; Fadiga and Craighero, 2004; Munzert et al., 2009) and preserve the same spatiotemporal characteristics according to Demougeot. Demougeot suggested that if the two components are related that one will have to mentally prepare or exercise the mind to have optimal performance. ..â??Appropriate mental training can enhance motor performance.â?? Demougeot seek to find the answer to have much physically activity or muscle fatigue will start to have an effect on the mental stabilization of oneâ??s cognitions? In their study they measured the temporal features of actual and mental movements before and after muscle fatigueâ?¦ â??A strong prediction is that duration of mental actions should be sensitive to muscle fatigue, because the forward model receives as input the efferent copy of inappropriate motor commands and the perturbed state of the arm, both caused by muscle fatigue.â??

To conduct their study they used seventeen adults who were all health with no neurological problems who they used as participates. The participates then were asked to move their arms, physically and then mentally at different angles in a conducted sequence. They then tested the participate before and after the muscle fatigue.

They discovered that muscle fatigue significantly influenced the mental aspect of the experiment. Demougeot discovered that muscle fatigue significantly influenced alterations in the signaling used in mental cognition. They also discovered actual movements were in general slower immediately after fatigue, but progressively returned to prefatigue values. When applied to their study they discovered that mental movements were faster immediately after fatigue and gradually returned to prefatigue values. Demougeot studied the motor effent outflow signals to justify their thesis and this is what the concluded â??However, its efferent copy is available to the forward model, which naturally predicts very fast movements. Since during mental movements there is not sensory information, and state estimation derives from forward model alone, the brain continues to simulate faster mental movements after fatigue based on inappropriate (large) neural drives. This explains why mental movements were consistently faster than actual movements after fatigue, at least until their complete adaptation. This process, i.e., state estimation without sensory feedback, also explains the slower update of motor controller (i.e., motor commands) during mental compared to actual movements after fatigue. â??

Though neuroimaging Demougeot discovered that muscle fatigue can greatly impact oneâ??s ability to mentally function as proven above. One can also conclude that next time you stay up to study all night for an exam (muscle fatigue) that it could be detrimental to our test grade. Demougeot proved that muscle fatigue influences motor performance and action planning. Itâ??s no longer enough for physically training but mentally training is required now too.

To read full article please follow https://cuvpn.colorado.edu/content/31/29/,DanaInfo=www.jneurosci.org+10712.full

Have you ever experienced a ?gut feeling?? Gut feelings are also known as intuitions. I?m sure you?ve all hear about your mother?s intuition? if not ? I?m sure she?ll tell you ?Mother knows best!? We all know things that weren?t taught to us?but we still know them. For example, best friend says she?s ?okay? but you know she isn?t or your newborn is sick. A gut feeling is a sudden, unexplained judgment where we don?t know the source of origin.

Science has started to research how the stomach and brain are interconnected. ?The concept that the gut and the brain are closely connected, and that this interaction plays an important part not only in gastrointestinal function but also in certain feeling states and in intuitive decision making, is deeply rooted in our language.?(Mayer, 2011)

In the August issue of Nature Review Neuroscience, the article ?Gut feelings: the emerging biology of gut?brain communication,? talks about the foundation of why there are such feelings and the pathways that are taken to create those feelings. ?Recent neurobiological insights into this gut?brain crosstalk have revealed a complex, bidirectional communication system that not only ensures the proper maintenance of gastrointestinal homeostasis and digestion but is likely to have multiple effects on affect, motivation and higher cognitive functions, including intuitive decision making.?(Mayer, 2011) The article discusses the enteric nervous system and the signaling pathways that the gut and brain used to communicate ??The brain communicates to the viscera, including the gastrointestinal tract, through multiple parallel pathways, including the two branches of the autonomic nervous system (ANS), the hypothalamic?pituitary?adrenal (HPA) axis and the sympatho?adrenal axis (modulating the gut-associated lymphoid tissue), and descending monoaminergic pathways (modulating gain of spinal reflexes and dorsal horn excitability). ? (Mayer, 2011) The article then discuss the effect of the stomach to the brain. Most of the consciously perceived information about the stomach is that it?s used for digestion?this isn?t new information. ?However, recent evidence suggests that various forms of subliminal interoceptive inputs from the gut, including those generated by intestinal microbes, may influence memory formation, emotional arousal and affective behaviours.? (Mayer, 2011)

So why do we make decision based off no information but off our ?gut feelings?? Mayer suggests that we have some ?neurological basis? when it comes to our gut-interactions. She suggests that our gut feeling based decision is due to an interoceptive map of gut responses that develops in infancy and continues to develop throughout our stages of life.

The future holds new research on the crosstalk between the stomach and the brain. The primary focus is the mapping associated with the two. ?This includes the remarkable success in mapping the functional neuroanatomy of the ENS, in our understanding of how the brain modulates these ENS circuits and gut functions, and in unraveling the complexity of gut to brain signaling through multiple parallel but interacting communication channels.? (Mayer, 2011) With our current advances in the study of gut feelings we still have many unanswered questions? stay tuned for what science discover next.
To read full article, please visit https://cuvpn.colorado.edu/nrn/journal/v12/n8/full/,DanaInfo=www.nature.com+nrn3071.html

How effective is your caffeine in the morning?
"Caffeine, a widely consumed adenosine A1 and A2A receptor antagonist, is valued as a psychostimulant, but it is also anxiogenic. An association between a variant within the ADORA2A gene (rs5751876) and caffeine-induced anxiety has been reported for individuals who habitually consume little caffeine." How many cups do you drink in the morning before you feel like you are ready to take on the day? The average intake of caffeine is on average was 346 mg per day (equivalent to about three cups of ground coffee per day). What if I were to tell you that the coffee you are drinking scientifically isn?t helping that fatigue. "Although frequent consumers feel alerted by caffeine, especially by their morning tea, coffee, or other caffeine-containing drink, evidence suggests that this is actually merely the reversal of the fatiguing effects of acute caffeine withdrawal (James and Rogers, 2005; Sigmon et al, 2009)."

What if I were to tell you that caffeine has a negative side effect to your health, would you continue to drink it? Caffeine has been linked to hypertension, increased anxiety, nervousness, irritability and nausea. So why can coffee taste that good but have some many side effects? "These behavioral and physiological effects of caffeine occur primarily through antagonism by caffeine of the action of endogenous adenosine at adenosine A1 and A2A receptors (Fredholm et al, 1999)." This study has linked a SNP between caffeine and increased anxiety. "Specifically, it was found that 150 mg caffeine (equivalent to the amount of caffeine present in, eg, 1½ cups of ground coffee) increased anxiety in individuals carrying the TT genotype of the ADORA2A SNP rs5751876, but not in the CT and CC genotype groups (Alsene et al, 2003; Childs et al, 2008)." This study took 218 women and 198 men and administered two doses of caffeine 100mg in the morning and 150 mg shortly after. There was randomization on who would receive caffeine and who would have a placebo. The group of people took a pre-survey to make sure that all caffeine users drank approximately the same amount of caffeine. The day before the study, subjects were not allowed to drink anything that had caffeine in it. Surveys were given to check the anxiety, alertness and quality of headache.

"Another key finding of this study is that a clear anxiogenic effect of caffeine, larger i individuals with the ADORA2A rs5751876 TT genotype, was observed only for people who habitually consumed little or no caffeine (the N and L groups). Higher caffeine consumption appears to lead to substantial tolerance to this effect." They discovered that people who continue to drink caffeine at a high enough rate didn't experience the increased side-effects. They discovered that the subjects developed a tolerance to the caffeine. "Although frequent caffeine consumers experience minimal increased anxiety after caffeine consumption, they are at risk of at least two clear adverse effects of acute caffeine abstinence, namely low alertness and increased headache."

To sum it up people who are habitual users do not develop adverse side effects until they withdraw from the caffeine use. There is also research that has linked a SNP to increased anxiety secondary to caffeine assumption.
For reading of full article please visit http://www.nature.com/npp/journal/v35/n9/full/npp201071a.html

We Americans are so accustomed to a lifestyle of instant gratification, ease, and leisure; especially when making daily choices of what we consume individually. It's no surprise we face an unprecedented epidemic of obesity in this nation when you look at how corporate food companies cater to our demand for easy availability of virtually any type of food one could ever crave. Obviously location takes an important roll as well, but for most of us residing in urban areas, our communities are saturated with endless food options. We no longer need to get out of our car to get an eight-hundred calorie caramel macchiato in the mornings. There's something to be said about the fact that one can obtain endless high-fat and high-caloric meals at the very thought of hunger.

Researchers and statisticians seem to be very compelled in not only updating the nation's obesity statistics, but also in finding new ways to potentially counteract America's modern obesity outbreak. In the past, some of us have resorted to other behaviors and procedures in compensation such as workout rituals, personal trainers, diet pills, and even extreme actions like stomach-stapling, liposuction, etc. Regardless of whether they worked or not, it's about time something new came around.

In last month's publication of Nature & Neuroscience, and interesting study using mouse mutants to research insulin receptor function in the ventromedial nucleus of the hypothalamus (VMH). Provided that high-fat diets lead to the production of severely high levels of insulin (which we all know can initiate cascades of detrimental health issues such as diabetes, high blood pressure, etc.), Klöckener et al. suggest brain mechanisms in the VHM which if genetically modified, may be applicable to humans and anti-obesity treatments.

The VMH is a rather unclear and grey portion of the brain in terms of the knowledge that we currently know about it. We do know however, that it serves as one of the primary locations in the hypothalamus that mediates nutrient sensing, metabolism, and insulin receptor signaling. To guarantee an optimal energy environment for reproduction, the body monitors energy availability indirectly with the help of insulin and leptin that consistently circulate in the body. These two hormones can act to store fat as well as alert other metabolizing processes.

Steroidogenic factor 1 (SF-1) positive cells distribute across large parts of the VMH are directly involved with controlling systematic metabolism. These cells are highly responsive to insulin. Klöckener et al. identified a subpopulation of insulin-SF-1-positive cells in the VMH distinct from leptin-responsive neurons. They found that the systematic deletion of the insulin receptor in SF-1 expressing cells of the VMH caused no immediate changes in homeostasis. However, when both the control and mutant mice were exposed to high-fat diets, the modified SF-1 cell mice were protected from the development of obesity. It was reasoned that this protection from obesity was due to higher leptin sensitivity, since insulin was rendered useless in the mutant mice. Following this discovery, they found that the reinstatement of PtdInsP3 signaling downstream of the insulin receptor made the mutant mice that were previously protected from obesity, vulnerable again.

Even though all of the processes VMH carries out sill remains unclear, the mechanisms involved with insulin and high-fat diets are becoming clearer. These findings are on their way to future investigations where potential anti-obesity therapeutics may be revealed.

I think it's awesome that researchers are unveiling new methods that can potentially solve this epidemic in the near future and I strongly support such research for the benefit of the population. This compelling issue has not been mitigated to a satisfactory level even with counteracting behaviors as mentioned above. Statistically, just below twenty percent of the population in Colorado is diagnosed as clinically obese. It's ironic thought because Colorado tops the list for the least obese state in the nation. We clearly have to keep working, researching, and making changes in order for a valid solution to be found.