A quick search of Medline indicates that serotonin stimulates contractions in the colon.
********************** Cheri A. Budzynski, Ph.D. Assistant Professor of Psychology Heidelberg College 310. E. Market Street Tiffin, Ohio 44883 (419) 448-2000 ext. 2251 (419) 893-1986 ext. 4005 -----Original Message----- From: Nathalie Cote [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 03, 2003 8:53 AM To: Teaching in the Psychological Sciences Subject: Serotonin production in the colon 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 (http://www.drkaslow.com/html/neurotransmitter_depletion.html). (Please note that the skeptic in me started waving a big red flag when I visited that Web site.) 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. Finding myself unable to address his concerns, I did a search back through TIPS and found Stephen Black's comment on "brainy bowels" from March 2000 but no other emails. But I would like to know more about it. My assumption is that even if the gut is a major producer of serotonin, serotonin levels and effects in the gut may very well be independent from serotonin levels in the brain. So - 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? 2) The Web site above also makes the claim that "inadequate levels of serotonin and norepinephrine precursors in the diet are the number one cause of neurotransmitter depletion" from extended use of SSRI medications and argues that proper nutrition can keep depression from happening in the first place and can keep SSRIs effective in patients for a longer period without incremental dosage increases. So, is it the case that extended use of SSRIs depletes neurotransmitters? And is it the case that diet has a measurable effect on neurotransmitter levels in the brain? Nat ***** Nathalie Cote', Ph.D. Assistant Professor of Psychology Belmont Abbey College 100 Belmont - Mt. Holly Rd. Belmont, NC 28012 Tel 704-825-6754 Fax 704-825-6239 [EMAIL PROTECTED] > -----Original Message----- > From: Stephen Black [mailto:[EMAIL PROTECTED] > Sent: Friday, March 31, 2000 4:44 PM > To: TIPS > Subject: Brainy bowels > > > You know how people are always telling you your brains are in your > behind? Well, they could be right. Check out this instalment of > mystery neuroscientist's newsletter. > > (I wasn't going to make a habit of these posts. But I found this so > interesting yet off-the-wall I had to share it.) > > -Stephen > > ---------- Forwarded message ---------- > Date: Fri, 31 Mar 2000 05:27:37 -0800 > From: Mystery neuroscientist > Subject: BioPsych/ Neurogastroenterology > > U.S. News & World Report > Science & Ideas 4/3/00 > > The wisdom of the gut Those butterflies in your stomach are not just > in your mind > > By Rachel K. Sobel > > For reasons that still mystify researchers today, the stunning results > of this experiment went into hibernation for nearly half a century and > are only now receiving fresh validation. Indeed, no one in medicine > paid attention again until a fledgling neurobiologist began touting > its clinical value in 1965. "The idea that the gut can be operating > its own nervous system was shocking," recalls Michael Gershon, > now chair of the department of anatomy and cell biology at > Columbia University and author of The Second Brain, a 1998 > account of the acceptance of this scientific idea. Since the > 1980s, Gershon's colleagues have zealously embraced the > notion of "the little brain in the gut," as it's > affectionately known. "What Mother Nature had done, rather > than packing all of those neurons in the big brain in the > skull and sending long lines to the gut, is distribute the > microcomputer, the little brain, right along with the gut," > says Jackie Wood, a neurobiologist at Ohio State University. > > Now a full-blown renaissance in neurogastroenterology, the > nine-syllable code word for the study of the nerves entrenched in the > lining of the esophagus, stomach, small intestine, and colon has > researchers probing the depths of the digestive nervous system with > feverish intensity and surfacing with remarkable insights. This new > breed of neuroscientist, 300 strong, and counting, is shaping a novel > notion of the gut and deriving innovative ways to treat its > ailments. Last month, for example, the first drug ever > designed for irritable-bowel syndrome (IBS), called Lotronex, > arrived in doctors' offices. It's based on this new > understanding of the sentient gut and may, in fact, change > the way physicians handle this and related disorders. > > Daily chores. By peeling away the layers of padding that surround the > digestive tract, scientists have indeed unearthed some of the buried > secrets of the little brain. This miniature central processing unit, > whose 100 million-plus nerves number more than those in the spinal > cord, carries out many of its daily chores without guidance > from the brain. "Suppose the gut gets a message that the > pressure is up in the stomach. The brain doesn't get its > hands dirty with that kind of nonsense so the gut takes care > of it," explains Gershon. Not only does the gut direct its > own show, he adds, but its spidery projections trickle into > neighboring organs, commanding the pancreas and gallbladder > to aid with digestion. > > Though able to run itself, the little brain does stay in close touch > with the big brain via 1,000 or so nerve fibers. Scientists studying > this relationship have discovered that the gut-brain connection is at > the heart of some of the most visceral human emotions. A "gut > feeling," for example, isn't just a poetic conceit used to convey > intuition. It arises from the biological interplay between these two > intimately connected brains, says Emeran Mayer, a gastroenterologist > and professor of physiology at the University of California-Los > Angeles. When faced with an anxiety-ridden situation, the big > brain sends urgent messages to the little brain, which begins > orchestrating a physical response, read as gurgling or > "butterflies" in the stomach. These sensations are recorded > in an "emotional memory bank" residing in the big brain, says > Mayer, and the next time the big brain makes a decision in a > similar situation, it's not based on some intellectual > calculation. Rather, it's instantaneously formulated from > this catalog of previous bodily responses, gut feelings", > stored in the brain. > > Why some people feel the burden of stress in their gu and not for > instance, in their heart can also be explained by the close > communication between the brain and the gut. When the big brain > consciously perceives a stressful situation, it calls on its fraternal > twin through specialized cells called mast cells embedded in the gut's > lining. These mast cells secrete a chemical called histamine, which > activates the nerves controlling the gut, telling the muscles to > contract. Hence, the cramps and bathroom trips so often associated > with bouts of stress. > > The complex circuitry in the gut not only operates like a brain; it > looks uncannily similar to one, too. Just like the nerves in the brain > and spinal cord, those in the gut are naked, lacking an insulating > sheath that wraps around the rest of the body's nerves. Swishing among > the gut's nerves are serotonin, nitric oxide, carbon monoxide, and at > least 30 other neurochemicals, the same ones sloshing around in the > skull. Curiously enough, as healthy brains in the head and > gut resemble each other, so too do diseased ones. Scientists > have found that some Alzheimer's and Parkinson's patients > accumulate the same type of tissue damage in their bowels as > they do in their skulls, raising the possibility that these > disorders might someday be diagnosed by routine rectal biopsy. > > The fact that the two brains share so much of the same biology can > explain why psychiatric medications have side effects in the gut. > Antidepressants like Prozac, for instance, increase the presence of > serotonin in the spaces where nerves talk to each other in both > brains. While this neurochemical shift settles the big brain > emotionally, it causes the gut to squirm, leading to side effects like > abdominal cramping and diarrhea. > > Many investigators are taking their cues in treating gut disorders > from drugs that have worked on the brain. For example, Michael > Camilleri, a gastroenterologist at the Mayo Clinic, is treating a > variety of gastrointestinal disorders with Clonidine, a drug sometimes > used in psychiatry. Another medication called Imitrex, customarily > used to soothe the pangs of migraine headaches, has effectively healed > the gut in two studies by Belgian teams. And Lotronex, the recently > released treatment for irritable-bowel syndrome, came from an > anti-anxiety drug. > > If the arrival of Lotronex signals a new era in treatment, it also > goes a long way in debunking the popular notion that IBS is "all in > the head." Though IBS is a relatively common disorder, affecting as > many as 1 in 5 people, it is difficult to diagnose with conventional > methods. The chronic abdominal pain, discomfort, and irregular bowel > movements leave no trace in the lining of the gut because such > abnormalities presumably occur at the level of the nerves tucked > inside the gut. This lack of physiological evidence has led many > doctors to dismiss patients' complaints as psychosomatic. It's now > hypothesized that the nerves lining the gut are oversensitive > and overreact to gas and food passing by, thus causing pain > and cramping. "Lotronex suggests that there is a mechanism > that is malfunctioning either in the big brain or the little > brain, or both, or someplace in between," says Wood. "IBS is > not imagined." > > U.S.News & World Report Inc. All rights reserved. > http://www.usnews.com/usnews/issue/000403/gut.htm ---------------------------------------------------------------------- ------------------------------------------------------------------------ Stephen Black, Ph.D. tel: (819) 822-9600 ext 2470 Department of Psychology fax: (819) 822-9661 Bishop's University e-mail: [EMAIL PROTECTED] Lennoxville, QC J1M 1Z7 Canada Department web page at http://www.ubishops.ca/ccc/div/soc/psy Check out TIPS listserv for teachers of psychology at: http://www.frostburg.edu/dept/psyc/southerly/tips/ ------------------------------------------------------------------------ --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED] --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED]
