A body–brain circuit that regulates body inflammatory responses 2024 Jin et al

Abstract

The body-brain axis is emerging as a principal conductor of organismal physiology. It senses and controls organ function1,2, metabolism3 and nutritional state4-6. Here, we show that a peripheral immune insult powerfully activates the body-brain axis to regulate immune responses. We demonstrate that pro- and anti-inflammatory cytokines communicate with distinct populations of vagal neurons to inform the brain of an emerging inflammatory response. In turn, the brain tightly modulates the course of the peripheral immune response. Genetic silencing of this body-to-brain circuit produced unregulated and out-of-control inflammatory responses. By contrast, activating, rather than silencing, this circuit affords exceptional neural control of immune responses. We used single-cell RNA sequencing, combined with functional imaging, to identify the circuit components of this neuro-immune axis, and showed that its selective manipulation can effectively suppress the pro-inflammatory response while enhancing an anti-inflammatory state. The brain-evoked transformation of the course of an immune response offers new possibilities in the modulation of a wide range of immune disorders, from autoimmune diseases to cytokine storm and shock.

Paywall, https://www.nature.com/articles/s41586-024-07469-y

 

Found: the dial in the brain that controls the immune system

"Scientists have long known that the brain plays a part in the immune system — but how it does so has been a mystery. Now, scientists have identified cells in the brainstem that sense immune cues from the periphery of the body and act as master regulators of the body’s inflammatory response.

The results, published on 1 May in Nature1, suggest that the brain maintains a delicate balance between the molecular signals that promote inflammation and those that dampen it — a finding that could lead to treatments for autoimmune diseases and other conditions caused by an excessive immune response.

The discovery is akin to a black-swan event — unexpected but making perfect sense once revealed, says Ruslan Medzhitov, an immunologist at Yale University in New Haven, Connecticut. Scientists have known that the brainstem has many functions, such as controlling basic processes such as breathing. However, he adds, the study “shows that there is whole layer of biology that we haven’t even anticipated”."

https://www.nature.com/articles/d41586-024-01259-2

 

Presumably this guy has been asleep for two hundred years.

 

... or he's basing that on medical school knowledge, which also seem to be a bit tardy.

 

Sounds interesting. Let's hope it is relevant to ME/CFS and post-infectious illnesses.

 

I was under the impression that, maybe not with such high precision, this was already known. I guess what's significant is finding where and how? Or something like that. Or maybe the significance of vagus neurons in this process.

Although I'm annoyed by the odd body-brain framing, last I checked the brain is definitely part of the body, this could be highly significant, as in major breakthrough. Or not at all. I guess it all depends on what excites academic funding institutions more than anything, who don't seem all that interested in basic science anymore.

I remember a comment VanElzakker made some years ago about how neurologists aren't interested in the old brain anymore, all the cool kids only look at the neocortex and higher/newer brain regions. It'll be good if neurology gains some interest back in the basics, there's definitely a whole lot more to work out here, away from all the nonsense about agency, dysfunctional networks and effort preferences.

 

My point exactly.

Every tiny bit of data, whether good or bad is now a major breakthrough.

When you get to my age it is even hard to move the head on its own - the neck gets a bit like a rusty shower head fitting.

The hypothalamus does have major influences on the immune system but to be honest, when disease strikes it mostly carries on the way it wants and ignores the head bit.

ME/CFS might be different, but the more I think about it the more I doubt there is actually anything wrong above the Adam's apple. Other than the misery that comes from down below.

 

Hasn't it been fashionable at various times to consider parts of the body as distinctly separate? I seem to recall the word "privileged" applied to the brain, meaning completely separated from the rest of the body's immune systems. I think it's easier to publish new findings than to delete old misconceptions.

Medical school teachers learned those old misconceptions, and pass them on to their students. How many generations does it take to remove those misconceptions from the education system?

 

Yeah I guess it's just been taken a little to excess, the blood-brain barrier is definitely significant but it seems to have been taken as license to consider it basically the equivalent of "air-gapped" with physical system security.