Article: The Tantalizing Links Between Gut Microbes and the Brain [Nature]

“Meanwhile, researchers were starting to uncover ways that bacteria in the gut might be able to get signals through to the brain. Pettersson and others revealed that in adult mice, microbial metabolites influence the basic physiology of the blood–brain barrier4. Gut microbes break down complex carbohydrates into short-chain fatty acids with an array of effects: the fatty acid butyrate, for example, fortifies the blood–brain barrier by tightening connections between cells (see ‘The gut–brain axis’).

“Recent studies also demonstrate that gut microbes directly alter neurotransmitter levels, which may enable them to communicate with neurons. For example, Elaine Hsiao, a biologist now at the University of California, Los Angeles, published research5 this year examining how certain metabolites from gut microbes promote serotonin production in the cells lining the colon — an intriguing finding given that some antidepressant drugs work by promoting serotonin at the junctions between neurons. These cells account for 60% of peripheral serotonin in mice and more than 90% in humans.

“Like the Karolinska group, Hsiao found that germ-free mice have significantly less serotonin floating around in their blood, and she also showed that levels could be restored by introducing to their guts spore-forming bacteria (dominated by Clostridium, which break down short-chain fatty acids). Conversely, mice with natural microbiota, when given antibiotics, had reduced serotonin production. “At least with those manipulations, it’s quite clear there’s a cause–effect relationship,” Hsiao says.”

Read the full article from Nature by Peter Andrey Smith: The Tantalizing Links Between Gut Microbes and the Brain

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Article: Where Does Somatic Memory in the Body Reside? [Fascia & Fitness]

“Traumatic memories are often experienced as “relived” rather than remembered, which is why people experiencing them react as though they are re-experiencing the situations in which they were traumatized. When a traumatic memory is triggered, the somatosensory experience of the person reliving the memory can be powerful; the whole body “remembers” and replicates the sensations of the trauma, including sympathetic nervous system fight, flight, or freeze responses. The psychophysiological experience is of reliving the trauma, what we call a flashback. In this situation, the client often effectively dissociates from the present reality and is caught in the state of re-living the traumatic memory.

“Whereas memories of ordinary events, even those containing somatosensory and emotional components, do not have the somatosensory texture and depth of flashbacks, making it much easier to remain connected to external stimuli and to experience being present in the moment while simultaneously feeling (remembered) sensations or emotions.”

[The article continues with remarks from Til Luchau, who I desperately want to train with some day. I have to be content with his Advance Trainings fb group for the time being.]

The state-dependant memory model discussed above [not included in this excerpt, read the full article] is more nuanced and sophisticated, and so arguably more useful. It brings to mind a book I’m currently reading: Lisa Feldman Barrett’s How Emotions are Made (2017, Houghton Mifflin Harcourt. ISBN 9780544133310). In her “theory of constructed emotions,” Barrett builds on the idea that our brains are structured to predict what we will see, taste, here, and feel. Apparently, there’s good evidence that the brain only processes things it does not predict. In this model, preloaded but widely networked caches of information (concepts) and meaning (valence) are used to minimize the brain’s energy use and maximize processing time.

“Interestingly, she writes that the brain’s wiring causes internal sensation and body signals (interoception and proprioception) to reach the brain’s processing centers before external perceptions (exteroception), such as sight, hearing etc. This sets up the brain to rapidly predict what it’ll perceive exteroceptively, based largely on past bodily experience (as well as language) what’s going to happen outside. In other words, we take in sensory information only until our brains can predict what will happen.
 
“This is the proposed mechanism behind both perceptions and emotion: for example, in this model, we are not reacting to our perceptions with emotions, we are neurologically predicting what will happen, and it is our predictions that shape our perceptions, emotions, and actions.”
 
Read the full article (and Til’s full commentary, plus comments from Walt Fritz) from Fascia & Fitness: Where Does Somatic Memory in the Body Reside?
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Article: 100 Million Americans Have Chronic Pain. Very Few Use One of the Best Tools to Treat it. [Vox]

“After weaning himself off the opioid Vicodin and feeling like he had exhausted every medical option, Golson turned to a book that described how pain could be purely psychological in origin. That ultimately took a pain psychologist, a therapist who specializes in pain — not a physician — to treat the true source: his fearful thoughts. Realizing that psychological therapy could help “was one of the most profoundly surprising experiences of my life,” Golson says. No doctor he ever saw “even hinted my pain might be psychogenic,” meaning pain that’s psychological in origin.

“Golson was lucky; few chronic pain patients ever get the chance to understand the psychological dimensions of their pain or try psychological therapies.

“There are 100 million Americans who suffer from chronic pain, and an unknown number of them are like Golson, with back pain, neck pain, fibromyalgia symptoms, or other forms of pain that have no diagnosed physical cause.

“It’s not that their pain is “in their heads.” The truth is much more nuanced: All pain can have both physical and psychological components. But the psychological component is often dismissed or never acknowledged.

“Big pharma’s aggressive marketing of pills and the minimal training doctors get in pain medicine mean that for too long, the go-to treatment for many forms of chronic pain has been opioids. Yet opioids have proven to be not only largely ineffective for treating most chronic pain but also highly addictive and risky.

“Cognitive behavioral therapy, meanwhile, shows meaningful benefits on chronic pain — both for psychogenic pain, and for pain with a physical cause — according to systematic reviews of the research. There’s also promising research around mindfulness-based stress reduction and therapies inspired by it.

“Yet pain psychologists are hard to find and hard to pay for, and most patients don’t even know they exist. “At the moment, [these therapies] tend to be seen as a route of no hope for the hopeless, for people who have gone through everything else,” says Amanda Williams, a psychological researcher who conducted one of the reviews of studies on the effectiveness of psychological therapy for pain.

“The question, then, is how we shift our understanding of pain so that psychology is the opposite of a last resort.”

Read Brian Resnick’s full article on Vox: 100 Million Americans Have Chronic Pain. Very Few Use One of the Best Tools to Treat it.

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