Sunday, November 27, 2016

Sacral outflow is entirely sympathetic

The book, Dermo Neuro Modulating, is out on Amazon as ebook only just now.. seems to be selling well based on feedback from twitter and facebook, but really I have no idea of stats, or of when the hard copies will be available, and won't until the coming week when I can converse with the company that helped me self-publish.

For the time being, if anyone interested in taking a look or picking up an e-copy, here is a book link to Amazon.

Time for a nerdy, nerdy interlude. 

In the past week it came to light that researchers got right down to the molecular level and found out that autonomic sacral outflow is entirely sympathetic, that there is no such thing as a parasympathetic cord supplying neurons to pelvic viscera or reproductive or sexual response function. This is huge news. Before I express any thoughts on that, here is Peggy Mason on the topic: 

Here is a blogpost she wrote on this topic! It examines a few of the implications from a science perspective, including the history of the concept and why textbooks will have to be updated.

Peggy Mason works at U. Chicago. I first encountered her brilliance at the IASP congress in Montreal in 2010. She discussed brainstem nuclei involved in micturition. I think that's her specific research area. But she does much much more besides. She teaches an online course for free, through Coursera, Understanding the Brain: The Neurobiology of Everyday Life. I signed up for it a few years ago but it was in May and I underestimated the daunting time factor. I had to run around teaching, myself, so had to drop out. But the amount I managed to assimilate was great, and I recommend it. She's a very engaging teacher.

She has also written a book, Medical Neurobiology. What I love about it is the non-hierarchical format - every single topic and even every little sidebar is connected to bits in other chapters, all the way through. Which means you have to turn a lot of pages frequently in a rather heavy book, but your brain is going to take in the information from lots of sides and angles and directions.

About the sacral outflow thing, clearly this is a big shift in the dogma surrounding neuroscience. I love that she's so excited about it! I know a lot of people whose world if rocked or their worldview pulled out from under them makes them anxious and upset. What does she say? She's excited, and says Whee!!!!

Anyway, here is what the new, more updated picture of sacral outflow looks like, from the Espinosa-Medina et al paper:


OK, so what is the big deal? For manual therapists?
Well, the implications are kind of big, in my opinion.
First of all, there are still plenty of us roaming around imagining that there is some sort of magical elicitation of parasympathetic activity directly stemming from hands-on work. So much so that there is even a kind of guru-based modality empire out there called craniosacral therapy. That set of ideas needs to go. 

Second of all, and more importantly I think, we need to understand that when we do hands-on we are playing with the brain, and that EVERYthing we touch or do is going to excite, for better or worse, the sympathetic nervous system. The sympathetic nervous system has dual control of the entire body wall, and blood flow to each and every bit of it, including to that forest of highly sensitive neural tree comprised of 72 kilometers of passive noodle-y tubing throughout our body. THAT is what it is most protective of, and that extends to the surface of the body, everywhere. Really. Everywhere.
Think about it.
Think about how everything that was ever thought about how sex works (i.e., an orchestrated interchange of sympathetic and parasympathetic outflow), is wrong in light of this new information.
If this is how sex really works, then it must also be how any kind of manual therapy works, also. Because if there is no parasympathetic outflow to genitalia there certainly is none running out anywhere else in the body wall, either.
Which supports the idea that context is everything, and that descending modulation from brainstem nuclei is where it is truly at, for blocking ascending nociception, and (given everything else is level) for pain relief.


1. I. Espinosa-Medina, O. Saha, F. Boismoreau, Z. Chettouh, F. Rossi, W. D. Richardson, J.-F. Brunet; The sacral autonomic outflow is sympathetic. Science  18 Nov 2016:
Vol. 354, Issue 6314, pp. 893-897

2. Adameyko I, Neural circuitry gets rewired. Science 18 Nov  2016 • Vol. 354 Issue 6314, pp. 833-4

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