Introducing the brain: controls 'feeling sick (Introduction)

by David Turell , Thursday, February 23, 2023, 19:20 (426 days ago) @ David Turell

The brain recognized when the illness appears and creates how you feel, your fever, etc.:

https://www.nature.com/articles/d41586-023-00509-z?utm_source=Nature+Briefing&utm_c...

"The difference in the hearts’ appearance originated in the brain, Haykin explains. The healthier-looking samples came from mice that had received stimulation of a brain area involved in positive emotion and motivation. Those marked with scars were from unstimulated mice.

“In the beginning we were sure that it was too good to be true,” Haykin says. It was only after repeating the experiment several times, she adds, that she was able to accept that the effect she was seeing was real.

"Haykin, alongside her supervisors at the Technion — Asya Rolls, a neuroimmunologist, and Lior Gepstein, a cardiologist — are trying to work out exactly how this happens. On the basis of their experiments so far, which have not yet been published, activation of this brain reward centre — called the ventral tegmental area (VTA) — seems to trigger immune changes that contribute to the reduction of scar tissue. (my bold)

"This study has its roots in decades of research pointing to the contribution of a person’s psychological state to their heart health1. In a well-known condition known as ‘broken-heart syndrome’, an extremely stressful event can generate the symptoms of a heart attack — and can, in rare cases, be fatal. Conversely, studies have suggested that a positive mindset can lead to better outcomes in those with cardiovascular disease. But the mechanisms behind these links remain elusive.

"For Rolls, the implications of this work are broad. She wants to provide an explanation for a phenomenon that many clinicians and researchers are aware of: mental states can have a profound impact on how ill we get — and how well we recover. In Rolls’s view, working out how this happens could enable physicians to tap into the power of the mind over the body. Understanding this could help to boost the placebo effect, destroy cancers, enhance responses to vaccination and even re-evaluate illnesses that, for centuries, have been dismissed as being psychologically driven, she says. “I think we’re ready to say that psychosomatic [conditions] can be treated differently.”

"She is part of a growing group of scientists who are mapping out the brain’s control over the body’s immune responses. There are multiple lines of communication between the nervous and the immune systems — from small local circuits in organs such as the skin, to longer-range routes beginning in the brain — with roles in a wide range of diseases, from autoimmunity to cancer. This field “has really exploded over the last several years”, says Filip Swirski, an immunologist at the Icahn School of Medicine at Mount Sinai in New York City."

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"Veiga-Fernandes and his group have documented clusters of neuronal and immune cells in various tissues and discovered how they work together to sense damage and mobilize immune reactions. His team is now looking at how these little switchboards can be controlled by the brain.

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"The brain itself is also beginning to give up its secrets. Neuroscientist Catherine Dulac and her team at Harvard University in Cambridge, Massachusetts, have pinpointed neurons in an area called the hypothalamus that control symptoms including fever, warmth-seeking and loss of appetite in response to infection6. “Most people probably assume that when you feel sick, it’s because the bacteria or viruses are messing up your body,” she says. But her team demonstrated that activating these neurons could generate symptoms of sickness even in the absence of a pathogen. An open question, Dulac adds, is whether these hypothalamic neurons can be activated by triggers other than pathogens, such as chronic inflammation.

"Just above the hypothalamus sits a region called the insula, which is involved in processing emotion and bodily sensations. In a 2021 study, one of Rolls’s doctoral students, Tamar Koren, found that neurons in the insula store memories of past bouts of gut inflammation — and that stimulating those brain cells reactivated the immune response7.

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"Negative mental states can also influence the body’s immune response. In a study published last year, Swirski and his team identified specific brain circuits that mobilize immune cells in the bodies of mice during acute stress10. The researchers found two pathways, one originating in the motor cortex that directed immune cells to the site of injury or infection, and another beginning in the hypothalamus — a key responder in times of stress — that reduced the number of immune cells circulating in the blood. The group is now investigating the role of stress-mediated circuits in chronic inflammatory diseases."

Comment: as you read this brain 'connectivity to everything' article, just recall now powerful is the placebo effect. Chance mutations cannot create this. It must be designed.