Article: Traumatic Brain Injury Causes Intestinal Damage [Neuroscience News]

“This is the first study to find that TBI in mice can trigger delayed, long-term changes in the colon and that subsequent bacterial infections in the gastrointestinal system can increase posttraumatic brain inflammation and associated tissue loss. The findings were published recently in the journal Brain, Behavior, and Immunity.

“These results indicate strong two-way interactions between the brain and the gut that may help explain the increased incidence of systemic infections after brain trauma and allow new treatment approaches,” said the lead researcher, Alan Faden, MD, the David S. Brown Professor in Trauma in the Departments of Anesthesiology, Anatomy & Neurobiology, Psychiatry, Neurology, and Neurosurgery at UMSOM, and director of the UMSOM Shock, Trauma and Anesthesiology Research Center.

“Researchers have known for years that TBI has significant effects on the gastrointestinal tract, but until now, scientists have not recognized that brain trauma can make the colon more permeable, potentially allowing allow harmful microbes to migrate from the intestine to other areas of the body, causing infection.. People are 12 times more likely to die from blood poisoning after TBI, which is often caused by bacteria, and 2.5 times more likely to die of a digestive system problem, compared with those without such injury.

“In this study, the researchers examined mice that received an experimental TBI. They found that the intestinal wall of the colon became more permeable after trauma, changes that were sustained over the following month.

“It is not clear how TBI causes these gut changes. A key factor in the process may be enteric glial cells (EGCs), a class of cells that exist in the gut. These cells are similar to brain astroglial cells, and both types of glial cells are activated after TBI. After TBI, such activation is associated with brain inflammation that contributes to delayed tissue damage in the brain. Researchers don’t know whether activation of ECGs after TBI contributes to intestinal injury or is instead an attempt to compensate for the injury.”

Read the full article at Neuroscience News: Traumatic Brain Injury Causes Intestinal Damage

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Article: Physiotherapy Works Better When You Believe it Will Help You [The Conversation]

“What surprised us was that patients who had said they expected to “completely recover” as a result of physiotherapy did even better than patients who expected to “much improve”.

“The most important predictor of outcome was the person’s pain and disability at the first appointment. Higher levels of pain and disability were associated with higher levels six months later. And lower baseline levels were associated lower levels six months later. But this relationship often changed for people who had high “pain self-efficacy”, that is, confidence in the ability to carry on doing most things, despite having shoulder pain.

“Another surprise finding was that people with high baseline pain and disability, but with high levels of pain self-efficacy did as well as, and sometimes better than, people with low baseline pain and disability and low pain self-efficacy.

“This is the first study to investigate patient expectations of the outcome of physiotherapy for shoulder pain. Earlier research shows that high patient expectation of recovery predicts a better outcome following physiotherapy for back pain and neck pain, and a better outcome following orthopaedic surgery.

“On a similar note, this is the first study to show that higher pain self-efficacy predicts a better outcome in non-surgically managed shoulder pain. Previous research has shown that self-efficacy predicts a better outcome for a range of other health conditions. Also, people with higher self-efficacy are more likely to do the home-exercise programme  suggested by their physiotherapist.”

Read Rachel Chester’s full article at The Conversation: Physiotherapy Works Better When You Believe it Will Help You

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Article: Spinal Cord is ‘Smarter’ Than Previously Thought [Medical Xpress]

“This research has shown that a least one important function is being done at the level of the spinal cord and it opens up a whole new area of investigation to say, ‘what else is done at the spinal level and what else have we potentially missed in this domain?'” said the study’s senior and supervising researcher Andrew Pruszynski, Ph.D., assistant professor at Western’s Schulich School of Medicine & Dentistry and Canada Research Chair in Sensorimotor Neuroscience.

“The study, “Spinal stretch reflexes support efficient hand control,” will be published online in the high impact journal Nature Neuroscience.

“This kind of hand control requires sensory inputs from multiple joints—mainly the elbow and the wrist—and these inputs was previously thought to be processed and converted into motor commands by the brain’s cerebral cortex.

“Using specialized robotic technology, a three degree of freedom exoskeleton at Western’s Brain and Mind Institute, subjects were asked to maintain their hand in a target position and then the robot bumped it away from the target by simultaneously flexing or extending the wrist and elbow. The researchers measured the time that it took for the muscles in the elbow and wrist to respond to the bump from the robot and whether these responses helped bring the hand back to the initial target.

“By measuring the latency, or ‘lag’, in the response, they were able to determine whether the processing was happening in the brain or the spinal cord.

“We found that these responses happen so quickly that the only place that they could be generated from is the spinal circuits themselves,” said the study’s lead researcher Jeff Weiler, Ph.D., a post-doctoral fellow at Schulich Medicine & Dentistry. “What we see is that these spinal circuits don’t really care about what’s happening at the individual joints, they care about where the hand is in the external world and generate a response that tries to put the hand back to where it came from.”

Read the full summary from University of Western Ontario at Medical Xpress: Spinal Cord is ‘Smarter’ Than Previously Thought

Their citation: Spinal stretch reflexes support efficient hand control , Nature Neuroscience (2019). DOI: 10.1038/s41593-019-0336-0 , https://www.nature.com/articles/s41593-019-0336-0

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Article: Germs in Your Gut are Talking to Your Brain. Scientists Want to Know What They’re Saying. [NY Times]

“For some neuroscientists, new studies have changed the way they think about the brain.

“One of the skeptics at that Alzheimer’s meeting was Sangram Sisodia, a neurobiologist at the University of Chicago. He wasn’t swayed by Dr. Cryan’s talk, but later he decided to put the idea to a simple test.

“It was just on a lark,” said Dr. Sisodia. “We had no idea how it would turn out.”

“He and his colleagues gave antibiotics to mice prone to develop a version of Alzheimer’s disease, in order to kill off much of the gut bacteria in the mice. Later, when the scientists inspected the animals’ brains, they found far fewer of the protein clumps linked to dementia.

“Just a little disruption of the microbiome was enough to produce this effect. Young mice given antibiotics for a week had fewer clumps in their brains when they grew old, too.

“I never imagined it would be such a striking result,” Dr. Sisodia said. “For someone with a background in molecular biology and neuroscience, this is like going into outer space.”

“Following a string of similar experiments, he now suspects that just a few species in the gut — perhaps even one — influence the course of Alzheimer’s disease, perhaps by releasing chemical that alters how immune cells work in the brain.

“He hasn’t found those microbes, let alone that chemical. But “there’s something’s in there,” he said. “And we have to figure out what it is.”

Read Carl Zimmer’s full article at The New York Times: Germs in Your Gut are Talking to Your Brain. Scientists Want to Know What They’re Saying.

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