Wednesday, August 24, 2011

Fundamental neurotransmission is not that simple

This is the kind of discovery that leads scientists to say, "What's happening is not a simple, monolithic process."


And when they say that, you know they're starting to pay attention. 

This fascinating discovery is a matter of function, not form. I gripe about the simplistic, even boneheaded science that seeks to uncover neurology by approaching it with a backhoe. This is one example of the more productive & telling approach, using the scientific equivalent of brushes and trowels. Good stuff, intelligent and apt. 

The radical new idea is this: the little blobs of neurotransmitters that sit between the nerve endings are not identical little blobs, but are in two separate sets of blobs. 

So what do they do?

The smaller group of blobs is the "recycling" set, called that because they get used and restocked each time the nerve fires. The larger group of blobs hangs back out of the way, and occasionally a blob takes off but not because the nerve just fired. Due to their relaxed attitude, these are called the "resting" set. 

In the article, the blobs are referred to as sacs (or "vesicles," in med-speak.) They're sacs in precisely the same way that the drop of water rolling across the hood of your car is a sac. The blobs have a sort of "skin" created by molecules gathering more densely at the surface, but nothing more. 

It's an important layer of molecules, though, since the detectable difference between the "resting" blobs/sacs and "recycling" sacs is the proteins that gather on their surfaces. 

Now, to discover what those proteins mean ... That's another study. I look forward to it. 

Thursday, August 11, 2011

Scared of the wrong things: depressive chemistry and danger

Funny how the whole delicate neurological/neurochemical structure is so interwoven:


"...The researchers suggest that the strange defensive behavior exhibited by the enzyme-deficient mice may actually reflect a limited range of adaptive responses and lack of emotional flexibility -- the mice may only have one gear for fear."

We've all known people who make exaggerated choices around danger that make no sense to ourselves. (Having heard my mother and my sometime partner on the subject of my riding motorcycles, I'm pretty sure of that.) However, only at my most desperately depressed have I engaged in unsafe sex, which is the second stupidest risk I can think of (the first having nothing to do with motorcycles.) 

The role of MAO-A and depressive neurotransmitters, combined with the dopamine-deficient sense of hopelessness and diminished executive function, make that make sense: 

"Monoamine oxidase A is the main enzyme in the brain that breaks down serotonin, norepinephrine and dopamine..."

Which makes me think that it's possible, in humans in vivo, to be deficient in both MAO-A and in dopamine, serotonin, etc. It would explain a lot about certain mental states, even though it seems chemically tautological at first glance to be both Big 3-deficient and MAO-A deficient. As I've learned, though, deficiency and dysregulation do have additive effects, they don't cancel each other out. 

I'd like to see more studies which monitor serum and brain levels of these key chemicals together, preferably in humans. Science tends to take the simplest possible approach, which is rarely the most realistic and not necessarily the most telling. It does get funded and it does make it simpler to design the studies. 

I look forward to having more sophisticated thinkers (and funders) get into this branch of psychoneurology, since all these lively lovely tiny bits of info won't come together in a meaningful way until we can look at them in concert with a higher degree of exactitude and completeness. I suppose I'll have to be patient. And careful. 

Monday, August 1, 2011

Good medicine

Long silence. It's not that I've been uninspired by recent medical science.

I've been traveling, spending a lot of time with people I haven't seen in many years. They've turned out to be the kind of people who, as the body get more chewed up, the personality gets richer and smoother. Proud to love them. Delighted to be with them.

Now that's good medicine.