TRIBUTARY - PART II

Barrett L. Dorko, P.T.

         
		"The Cuyahoga River
		Goes smokin' through my dreams
		... Now the Lord can make you tumble
		    And the Lord can make you turn
		    And the Lord can make you overflow
		    But the Lord can't make you burn

		Burn on, big river, burn on"

                                  Randy Newman on "Sail Away"
                                                     1972
I wrote in Part I of this piece that rivers and neural tissue had much in common, and that if you can't actually touch one of them directly, you still had a shot at affecting them through a tributary. I want to be specific about that structure here, and tell you how I discovered it.

There's a small store between the Cuyahoga and my home. It's full of those kinds of items husbands are often sent to pick up on their way home from work, or just after they've settled on the couch. At least it seems that's when I go there most often.

At the Y-Mart you can find Kleenex or orange sherbet, peanut butter or plant food. I see men lined up at the checkout with remarkably odd combinations of things.

Years ago I was wandering by the magazine rack here (I think I was looking for evaporated milk and eye drops) when I saw a copy of "The Sciences."* I leafed through it and found my understanding of manual technique transformed.

The tributaries of the Cuyahoga include a few small streams and creeks in Northern Ohio that we can see and touch. But, if you think about it, my own back yard drains into these and then on to the larger river. I mean the water that falls here has to go somewhere, and when the water tables are full in the Spring a little change here can have a dramatic effect on the river down the street, past the Y-Mart.

Although many caregivers pride themselves on their ability to see subtle phenomena and interpret their meaning (this includes me), it is our understanding of that which can't be seen that separates science from mere intuition.

I can't see any stream in my backyard because the structures beneath the grass that transport the water are too small to pick up with the naked eye. They make up for this with sheer numbers.

In the early eighties a neurobiologist named Frederick Sachs found that by using a new devise he could separate and study a single cell. Until then the exact mechanism that led to nervous depolarization secondary to touch was unknown. The known channels allowing passage of ions necessary for an action potential were present in the nervous tissue but not in the skin. It was as if we knew that water falling in my backyard flowed to the river, but we couldn't see how.

Sachs discovered "stretch-activated" ion channels that opened sufficiently to allow an influx of potassium and the activation of mechanoreceptors whenever a cell was deformed. He found them in virtually all cells, including the epithelium, thus explaining proprioception as well as the sensation of touch.

He also discovered that the amount of depolarization achieved was directly proportional to the membranous tension of the cell being deformed. The "leaking" of potassium increases in taut, facilitated areas of the skin. Think of why you shouldn't press on the side of a canvas tent in the rain, of how a little rain in my back yard will affect the river when the water table is swollen. Think of what it's like to touch a scar.

Sometimes the nervous tissues within are inflamed, and, like the Cuyahoga in Cleveland back in the sixties, it doesn't take much to get them fired. Touch won't help this. You need to clean up the chemicals that don't belong. That's what doctors are for.

I give a lecture on ion-channels to my students and then tell them to go to the tributaries in the body. I want them to learn to change the river from a distant but effective place. And sometimes they begin to understand.

* "The Intimate Sense: Understanding the Mechanics of Touch" Frederick Sachs in "The Sciences: Jan/Feb 1988