Thank you, David. This is a good answer to keep in my received mail as a good example of what happens on some of these wacko websites. Now, if you could give just a few references to support your major points..... :-)
Annette Quoting David Epstein <[EMAIL PROTECTED]>: > On Wed, 3 Sep 2003, Nathalie Cote went: > > > One of my Intro Psych students told me that he found a Web site that > > says that the gastrointestinal tract is a bigger producer of serotonin > > than the brain is > > That's what I've been taught--that 90% of the body's serotonin is in > the gut, where it serves functions related to intestinal motility. > > > The student is concerned because he has had his colon removed for > > medical reasons, so he wants to know if that affects serotonin > > levels in his brain. > > No, there's nothing to worry about there. Serotonin doesn't penetrate > the blood-brain barrier, so the student's digestive tract can make as > much (or as little) serotonin as it likes, and his brain won't know > the difference, so to speak. > > Serotonin in the brain is made in specific clusters of neuron in the > brainstem, whose axons form specific pathways with specific (perhaps > even opposing) functions in various other brain regions. It's not > something that the brain needs to be globally bathed in, like > cerebrospinal fluid, and more isn't necessarily better. > > > 1) What do you know about serotonin in the gut? Other than being the > > same chemical, is it related to serotonin in the brain? How? > > I think that when nature finds a useful signaling molecule, it uses > that molecule wherever it can. So the same molecules tend to turn up > in a lot of different places; that doesn't have to mean they're > serving the same functions. > > > 2) The Web site above also makes the claim that "inadequate levels of > > serotonin and norepinephrine precursors in the diet > > ...probably constitute a condition that almost never occurs. > > > is it the case that extended use of SSRIs depletes > > neurotransmitters? > > No--at least, it's never been demonstrated. There are studies showing > that huge overdoses of SSRIs can damage serotonergic axons in rats. > Those studies have no implications for chronic use of therapeutic > doses. > > > And is it the case that diet has a measurable effect on > > neurotransmitter levels in the brain? > > Generally not, unless you go to unusual lengths, such as fasting, then > drinking specially made cocktails of amino acids from which tryptophan > is deliberately excluded. > > --David Epstein > [EMAIL PROTECTED] > > --- > You are currently subscribed to tips as: [EMAIL PROTECTED] > To unsubscribe send a blank email to [EMAIL PROTECTED] > Annette Kujawski Taylor, Ph. D. Department of Psychology University of San Diego 5998 Alcala Park San Diego, CA 92110 [EMAIL PROTECTED] --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED]
