
Vagus nerve stimulation: Shock tactics set to shake up immunology - sohkamyung
https://www.nature.com/news/the-shock-tactics-set-to-shake-up-immunology-1.21918
======
jphoward
I am such a huge cynic of this. This involves stimulating the parasympathetic
nervous system, which is the antagonist, so to speak, of the sympathetic
nervous system.

A few years ago a company called Ardian had a minimally-invasive system called
renal redervation for destroying the sympathetic nerves to the kidneys, in the
hope that it would cure high blood pressure. Initial unblinded single armed
trials were favourable, and so Ardian made $1,000,000,000 selling to
Medtronic.

Lo and behold, in the double-blinded randomised trial, renal denervation did
absolutely nothing.

Renal denervation was fuelled by optimism and bluff about the role for these
nervous systems in disease. Shock horror, however, when manually altering them
with a blunt tool such as ablation (in the case of renal denervation) or
stimulation (the example here), doesn't actually help.

The whole saga of renal denervation was one of the greatest examples of bad
science and optimism getting ahead of us. This is a nice editorial:
[http://jamesphoward.com/papers/RDE.pdf](http://jamesphoward.com/papers/RDE.pdf)

------
vorotato
Can't you stimulate the vagus nerve with a big meal or belly breathing? All
this time I thought people advising belly breathing were just a bunch of dirty
hippies who were afraid of the doctor. I wonder if there's something special
about HOW this stimulates the vagus nerve or if it's any stimulation at all.

~~~
cpncrunch
Even mindfulness meditation can stimulate the vagus nerve:

[https://www.psychologytoday.com/blog/the-athletes-
way/201602...](https://www.psychologytoday.com/blog/the-athletes-
way/201602/mindfulness-meditation-and-the-vagus-nerve-share-many-powers)

Since psychological factors have a large effect on vagus tone, it's important
to do double-blind trials.

------
amelius
> Exposure to acetylcholine, however, prevents macrophages from producing the
> inflammatory protein

But aren't there better ways to increase acetylcholine than stimulating the
vagus nerve?

~~~
joeyo
The promise of the "electroceutical" approach is localized neurotransmitter
release: you want to enact increased ACh in the body (and localized within the
body, if possible) but not in the CNS, where it would likely result in
undesired side effects.

You see the same phenomena in reverse with drugs intended for the brain (e.g.
for treating depression). The severe side effects of those drugs are because
the same neurotransmitter receptors involved in mood in the brain are involved
in digestion in the gut.

~~~
nikolay
Isn't A-GPC [0] proven to act just in the brain?

[0]: [https://examine.com/supplements/alpha-
gpc/](https://examine.com/supplements/alpha-gpc/)

~~~
joeyo
It looks like it is believed to be effective at crossing the blood-brain-
barrier. Is that equivalent to acting just in the brain? No idea, but it seems
unlikely.

