Summary: Weight bearing leg exercises send signals to the brain which are vital for the production of healthy neural cells, researchers report.

Source: Frontiers.

Groundbreaking research shows that neurological health depends as much on signals sent by the body’s large, leg muscles to the brain as it does on directives from the brain to the muscles. Published today in Frontiers in Neuroscience, the study fundamentally alters brain and nervous system medicine — giving doctors new clues as to why patients with motor neuron disease, multiple sclerosis, spinal muscular atrophy and other neurological diseases often rapidly decline when their movement becomes limited.

“Our study supports the notion that people who are unable to do load-bearing exercises — such as patients who are bed-ridden, or even astronauts on extended travel — not only lose muscle mass, but their body chemistry is altered at the cellular level and even their nervous system is adversely impacted,” says Dr. Raffaella Adami from the Università degli Studi di Milano, Italy.

The study involved restricting mice from using their hind legs, but not their front legs, over a period of 28 days. The mice continued to eat and groom normally and did not exhibit stress. At the end of the trial, the researchers examined an area of the brain called the sub-ventricular zone, which in many mammals has the role of maintaining nerve cell health. It is also the area where neural stem cells produce new neurons.

Limiting physical activity decreased the number of neural stem cells by 70 percent compared to a control group of mice, which were allowed to roam. Furthermore, both neurons and oligodendrocytes — specialized cells that support and insulate nerve cells — didn’t fully mature when exercise was severely reduced.

The research shows that using the legs, particularly in weight-bearing exercise, sends signals to the brain that are vital for the production of healthy neural cells, essential for the brain and nervous system. Cutting back on exercise makes it difficult for the body to produce new nerve cells — some of the very building blocks that allow us to handle stress and adapt to challenge in our lives.

“It is no accident that we are meant to be active: to walk, run, crouch to sit, and use our leg muscles to lift things,” says Adami. “Neurological health is not a one-way street with the brain telling the muscles ‘lift,’ ‘walk,’ and so on.”

The researchers gained more insight by analyzing individual cells. They found that restricting exercise lowers the amount of oxygen in the body, which creates an anaerobic environment and alters metabolism. Reducing exercise also seems to impact two genes, one of which, CDK5Rap1, is very important for the health of mitochondria — the cellular powerhouse that releases energy the body can then use. This represents another feedback loop.

These results shed light on several important health issues, ranging from concerns about cardio-vascular impacts as a result of sedentary lifestyles to insight into devastating diseases, such as spinal muscular atrophy (SMA), multiple sclerosis, and motor neuron disease, among others.

“I have been interested in neurological diseases since 2004,” says co-author Dr. Daniele Bottai, also from the Università degli Studi di Milano. “The question I asked myself was: is the outcome of these diseases due exclusively to the lesions that form on the spinal cord in the case of spinal cord injury and genetic mutation in the case of SMA, or is the lower capacity for movement the critical factor that exacerbates the disease?”

This research demonstrates the critical role of movement and has a range of potential implications. For example, missions to send astronauts into space for months or even years should keep in mind that gravity and load-bearing exercise play an important role in maintaining human health, say the researchers.

“One could say our health is grounded on Earth in ways we are just beginning to understand,” concludes Bottai.

Funding: Funding provided by Asamsi ONLUS, Italy and Vertical Foundation.

Source: Emma Duncan – Frontiers 
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Open access research for “Reduction of Movement in Neurological Diseases: Effects on Neural Stem Cells Characteristics” by Raffaella Adami, Jessica Pagano, Michela Colombo, Natalia Platonova, Deborah Recchia, Raffaella Chiaramonte, Roberto Bottinelli, Monica Canepari and Daniele Bottai in Frontiers in Neuroscience. Published May 23 2018
doi:10.3389/fnins.2018.00336

Abstract

Reduction of Movement in Neurological Diseases: Effects on Neural Stem Cells Characteristics

Both astronauts and patients affected by chronic movement-limiting pathologies face impairment in muscle and/or brain performance. Increased patient survival expectations and the expected longer stays in space by astronauts may result in prolonged motor deprivation and consequent pathological effects. Severe movement limitation can influence not only the motor and metabolic systems but also the nervous system, altering neurogenesis and the interaction between motoneurons and muscle cells. Little information is yet available about the effect of prolonged muscle disuse on neural stem cells characteristics. Our in vitro study aims to fill this gap by focusing on the biological and molecular properties of neural stem cells (NSCs). Our analysis shows that NSCs derived from the SVZ of HU mice had shown a reduced proliferation capability and an altered cell cycle. Furthermore, NSCs obtained from HU animals present an incomplete differentiation/maturation. The overall results support the existence of a link between reduction of exercise and muscle disuse and metabolism in the brain and thus represent valuable new information that could clarify how circumstances such as the absence of load and the lack of movement that occurs in people with some neurological diseases, may affect the properties of NSCs and contribute to the negative manifestations of these conditions.

Imagine the director of a big company announcing an important decision and justifying it with it being based on a gut feeling. This would be met with disbelief – surely important decisions have to be thought over carefully, deliberately and rationally?

Indeed, relying on your intuition generally has a bad reputation, especially in the Western part of the world where analytic thinking has been steadily promoted over the past decades. Gradually, many have come to think that humans have progressed from relying on primitive, magical and religious thinking to analytic and scientific thinking. As a result, they view emotions and intuition as fallible, even whimsical, tools.

However, this attitude is based on a myth of cognitive progress. Emotions are actually not dumb responses that always need to be ignored or even corrected by rational faculties. They are appraisals of what you have just experienced or thought of – in this sense, they are also a form of information processing.

Intuition or gut feelings are also the result of a lot of processing that happens in the brain. Research suggests that the brain is a large predictive machine, constantly comparing incoming sensory information and current experiences against stored knowledge and memories of previous experiences, and predicting what will come next. This is described in what scientists call the “predictive processing framework”.

This ensures that the brain is always as prepared to deal with the current situation as optimally as possible. When a mismatch occurs (something that wasn’t predicted), your brain updates its cognitive models.

This matching between prior models (based on past experience) and current experience happens automatically and subconsciously. Intuitions occur when your brain has made a significant match or mismatch (between the cognitive model and current experience), but this has not yet reached your conscious awareness.

For example, you may be driving on a country road in the dark listening to some music, when suddenly you have an intuition to drive more to one side of the lane. As you continue driving, you notice that you have only just missed a massive pothole that could have significantly damaged your car. You are glad you relied on your gut feeling even if you don’t know where it came from. In reality, the car in the far distance in front of you made a similar small swerve (since they are locals and know the road), and you picked up on this without consciously registering it.

When you have a lot of experience in a certain area, the brain has more information to match the current experience against. This makes your intuitions more reliable. This means that, as with creativity, your intuition can actually improve with experience.

Biased understanding

In the psychological literature, intuition is often explained as one of two general modes of thinking, along with analytic reasoning. Intuitive thinking is described as automatic, fast, and subconscious. Analytic thinking, on the other hand, is slow, logical, conscious and deliberate.

Many take the division between analytic and intuitive thinking to mean that the two types of processing (or “thinking styles”) are opposites, working in a see-saw manner. However, a recent meta-analysis – an investigation where the impact of a group of studies is measured – has shown that analytic and intuitive thinking are typically not correlated and could happen at the same time.

So while it is true that one style of thinking likely feels dominant over the other in any situation – in particular analytic thinking – the subconscious nature of intuitive thinking makes it hard to determine exactly when it occurs, since so much happens under the bonnet of our awareness.

Indeed, the two thinking styles are in fact complementary and can work in concert – we regularly employ them together. Even groundbreaking scientific research may start with intuitive knowledge that enables scientists to formulate innovative ideas and hypotheses, which later can be validated through rigorous testing and analysis.

What’s more, while intuition is seen as sloppy and inaccurate, analytic thinking can be detrimental as well. Studies have shown that overthinking can seriously hinder our decision-making process.

In other cases, analytic thinking may simply consist of post-hoc justifications or rationalisations of decisions based on intuitive thinking. This occurs for example when we have to explain our decisions in moral dilemmas. This effect has let some people refer to analytic thinking as the “press secretary” or “inner lawyer” of intuition. Oftentimes we don’t know why we make decisions, but we still want to have reasons for our decisions.

Trusting instincts

So should we just rely on our intuition, given that it aids our decision-making? It’s complicated. Because intuition relies on evolutionarily older, automatic and fast processing, it also falls prey to misguidances, such as cognitive biases. These are systematic errors in thinking, that can automatically occur. Despite this, familiarising yourself with common cognitive biases can help you spot them in future occasions: there are good tips about how to do that here and here.

Similarly, since fast processing is ancient, it can sometimes be a little out of date. Consider for example a plate of donuts. While you may be attracted to eat them all, it is unlikely that you need this large an amount of sugars and fats. However, in the hunter-gatherers’ time, stocking up on energy would have been a wise instinct.

Thus, for every situation that involves a decision based on your assessment, consider whether your intuition has correctly assessed the situation. Is it an evolutionary old or new situation? Does it involve cognitive biases? Do you have experience or expertise in this type of situation? If it is evolutionary old, involves a cognitive bias, and you don’t have expertise in it, then rely on analytic thinking. If not, feel free to trust your intuitive thinking.

It is time to stop the witch hunt on intuition, and see it for what it is: a fast, automatic, subconscious processing style that can provide us with very useful information that deliberate analysing can’t. We need to accept that intuitive and analytic thinking should occur together, and be weighed up against each other in difficult decision-making situations.

Funding: Valerie van Mulukom has worked on analytical and intuitive thinking research for projects funded by BIAL Foundation grants (62/06 and 380/14) awarded to Dr Miguel Farias (Coventry University).

Source: Valerie van Mulukom – The Conversation 
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is credited to Valerie van Mulukom.

Source: AASM.

According to a recent study, a newly developed algorithm may be the key to optimizing alertness with caffeine.

Caffeine is the most widely consumed stimulant to counter the effects of sleep loss on neurobehavioral performance. However, to be safe and most effective, it must be consumed at the right time and in the right amount. This study proposed an automated optimization algorithm to identify safe and effective caffeine-dosing strategies that maximize alertness under any sleep-loss condition.

“We found that by using our algorithm, which determines when and how much caffeine a subject should consume, we can improve alertness by up to 64 percent, while consuming the same total amount of caffeine,” said principal investigator and senior author Jaques Reifman, PhD. “Alternatively, a subject can reduce caffeine consumption by up to 65 percent and still achieve equivalent improvements in alertness.”

Reifman is a senior research scientist and director of DoD Biotechnology High Performance Computing Software Applications Institute and the Telemedicine and Advanced Technology Research Center at the U.S. Army Medical Research and Materiel Command in Ft. Detrick, Maryland.

The study used a validated mathematical model, which predicts the effects of sleep loss and caffeine on psychomotor vigilance task (PVT) performance and combined it with a computationally efficient optimization algorithm to determine when and how much caffeine to consume to safely maximize alertness during sleep loss. The algorithm takes a user-provided sleep/wake schedule and maximum allowed caffeine as inputs and provides a caffeine-dosing strategy as the output.

The algorithm was assessed by computing and comparing dosing strategies for four previously published experimental studies of sleep loss. For each study, two dosing strategies were computed–one which enhanced the predicted PVT performance using the same total amount of caffeine as in the original studies, and another which achieved an equivalent level of performance as in the original studies using a lower amount of caffeine.

Compared to the original dosing strategies used in the studies, the U.S. Army’s algorithm identified strategies that enhanced neurobehavioral performance by up to 64 percent, or reduced caffeine consumption by up to 65 percent. According to the authors, these results suggest that the algorithm can tailor the timing and amount of caffeine to the particular sleep/wake schedule of each study condition to maximize its benefits.

“Our algorithm is the first quantitative tool that provides automated, customized guidance for safe and effective caffeine dosing to maximize alertness at the most needed times during any sleep-loss condition,” said Reifman.

Source: Corinne Lederhouse – AASM 
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: The study “Caffeine Dosage Strategies that Efficiently Enhance Alertness during Sleep Loss” by Vital-Lopez F, Ramakrishnan S, Doty TJ, Balkin TJ, and Reifman J will be presented at SLEEP 2018.

Abstract

Caffeine Dosage Strategies that Efficiently Enhance Alertness during Sleep Loss

Introduction: Caffeine is the most widely consumed stimulant to counter the effects of sleep loss on neurobehavioral performance. However, to be safe and most effective, it must be consumed at the right time and in the right amount. Caffeine-dosing recommendations offered by prior studies are not readily adaptable to any arbitrary sleeploss condition. Here, we propose an automated optimization algorithm to identify safe and effective caffeine-dosing strategies that maximize alertness under any sleep-loss condition.

Methods: We used our validated unified model of performance, which predicts the effects of sleep loss and caffeine on psychomotor vigilance task (PVT) performance, and combined it with a computationally efficient optimization algorithm to determine when and how much caffeine to consume to safely maximize alertness during sleep loss. The algorithm takes a user-provided sleep/wake schedule and maximum allowed caffeine as inputs, and provides a caffeine-dosing strategy as the output. We assessed the algorithm by computing and comparing dosing strategies for six previously published experimental studies of sleep loss. For each study, we computed two dosing strategies—one which enhanced the predicted PVT performance using the same total amount of caffeine as in the original studies, and another which achieved an equivalent level of performance as in the original studies using a lower amount of caffeine.

Results: Compared to the original dosing strategies used in the studies, our algorithm identified strategies that enhanced neurobehavioral performance by up to 64%, or reduced caffeine consumption by up to 65%. These results suggest that the algorithm can tailor the timing and amount of caffeine to the particular sleep/wake schedule of each study condition to maximize its benefits.

Conclusion: Our algorithm is the first quantitative tool that provides automated, customized guidance for safe and effective caffeine dosing to maximize alertness at the most needed times during any sleep-loss condition.

Support (If Any): This work was sponsored by the Military Operational Medicine Program Area Directorate of the U.S. Army Medical Research and Materiel Command, Ft. Detrick, MD, and by the U.S. Department of Defense Medical Research and Development Program (Grant No. DMRDP_13200).