Posted by Racer on August 3, 2004, at 12:43:01
In reply to Re: I wish I knew, posted by tabitha on August 3, 2004, at 1:21:02
> And I'd love to know the relation between the level in the body and in the brain. I try to keep my SSRI dosage low enough that I don't get the undesirable body effects, but I wonder if it's necessary to have those effects to get the necessary brain boost.
>Well, the part about the relationship between body levels and brain levels is pretty easy: your brain is your body's most vital resource, so evolution has worked pretty hard to protect it. There is a natural barrier between the brain and the rest of the body, which limits the amount of any substance that can cross into the brain. That's all well and good -- kept grandma Lucy alive three and a half million years ago -- but it makes it difficult to get drugs into the brain, too. The blood-brain barrier is obviously not impermeable, but it's complicated, and most drugs do need to reach pretty high levels in the body before they can cross over into the brain. That's actually why there are known therapeutic windows for some of the TCAs, because the ratio of body to brain activity has been established.
> And I wonder-- do the other neurotransmitters also affect the entire body?
>
Yes, they do. All those neurotransmitters affect the entire nervous system. Obviously, there's a bit more of an impact on the cerebro-spinal system, but the rest of the nerves count in the neural network, too. I know that serotonin is involved in the gut, and in the allergies that affect my eyes, and in a bunch of other things, too. I think it's involved in connective tissue issues, but can't swear to it. Norepinephrine is part of the endocrine system, as I recall.I try to remember to realign my brain from time to time, to keep these things in perspective. For instance, one of the big topics in the science stuff I read recently has been the question: are animals more like humans than we'd thought? When I look at the articles, I see it differently: are humans really more like other mammals than we like to remember? Same basic question, just turned around. As applied to neurotransmitters, I think the question has to do with seeing the brain as another part of the body, and the central nervous system. It's scary -- at least for me -- to think of it this way, but it also helps me keep it in perspective, you know?
I hope that helps some. If I find anything, I'll post it here.
poster:Racer
thread:373268
URL: http://www.dr-bob.org/babble/health/20040729/msgs/373611.html