Scribal Terror

A new look at an old brain

Phineas Gage's, to be precise. Via Instapundit.

Image from Wikimedia.

"Prolonged rhythmic gum chewing" suppresses pain response

According to Mohri, Fumoto, et al. in the journal Pain 118 (2005) 35-40, and if you're put off by scientific jargon, just read the highlighted text:

Serotonergic (5-HT) neurons are implicated in modulating nociceptive transmission. It is established that 5-HT neuronal activity is enhanced by rhythmic behaviors such as chewing and locomotion in animals. We thus hypothesized that 5-HT descending inhibitory pathways may be enhanced by rhythmic behavior of gum chewing in humans. To evaluate this idea, we examined nociceptive flexion reflex (NFR), while a subject chewed gum rhythmically for 20min. NFR was elicited by electrical stimulation of the sural nerve, and the evoked potential was recorded from the biceps femoris muscle. Visual analogue scale (VAS) was also obtained. To assess 5-HT activity, we determined 5-HT levels quantitatively in platelet poor plasma (PPP) and whole blood (WB) using HPLC system. Both NFR area and VAS were significantly decreased at 5min after the onset of chewing and these reductions persisted until cessation of chewing. There were no significant changes in NFR and VAS while resting without chewing. The PPP 5-HT level increased significantly just after cessation of chewing and had returned to the pre-chewing level by 30min after cessation of chewing. The WB 5-HT level obtained 30min after cessation of chewing was significantly greater than the pre-chewing level. Serotonin transporters have recently been discovered at the blood–brain barrier, suggesting that the rise in blood 5-HT may possibly reflect an increase in 5-HT level within the brain. The present results support our hypothesis that the rhythmic behavior of chewing suppresses nociceptive [i.e., pain-sensing] responses via the 5-HT descending inhibitory pathway.

I've read the whole article and find it very compelling, especially since I had recently begun experimenting on myself after noticing that gum chewing relieved my chronic neck pain for up to a half hour after the fact -- I only went looking for the research when I had formed my own hypothesis, so no placebo effect was involved.

The key points are these: rhythmic, prolonged gum chewing has been shown to suppress pain responses. The subject needs to chew for at least 5-7 minutes before the effect occurs, then keep chewing for an additional 15 minutes. This should result in pain suppression that lasts about 30 minutes. These are exactly the results that I've been getting -- and when I want to relieve my pain again, I just chew more gum. You can't overdose. BTW, I use sugarless.

The main down side to gum chewing for pain suppression is that gum chewing has also been implicated in TMJ (temperomandibular joint syndrome), which is in itself a painful condition. I would not be doing this if the pain I experience were just an occasional thing. In fact, it's constant and I absolutely have to have a break from it. Think Chinese water torture. The alternatives are large quantities of ibuprofen (Advil) and/or muscle relaxants plus darvocet, an opioid, and I obviously have to restrict my intake of those. Not so for gum. I only wish I could find some truly nonsweet, taste-free gum. I get heartily sick of mint.

Snail-trail cough medicine

Let Michelle tell you about it.

Fight cancer with beer

Wired reports:

Researchers at Rice University are concocting a genetically engineered beer that could fight heart disease and cancers, ComputerWorld reports. The goal is to create a brew containing resveratrol, the same disease-fighting, natural chemical found in red wine.

The scientists are basing the premise of their project on research conducted by University of Wisconsin in June. In that study, researchers found that adding small doses of resveratrol to the diets of middle-aged mice signficantly extended their lifespans and kept their hearts healthy.

Plaudits for placebos

According to an interesting article in Mind Hacks, "Placebo is not what you think":

Placebos are not 'ineffective'. In fact, when three condition trials are run (no treatment vs placebo vs medical treatment), placebo consistently out performs 'no treatment' and of course, not uncommonly, the medical treatment condition as well.

Placebos are not a 'non-specific' treatment. A study on people who take the dopamine-boosting drug L-DOPA for Parkinson's disease but who took a placebo L-DOPA pill, showed almost identical brain changes, as if they'd taken the real thing.

Furthermore, studies done in the 1970s showed that when heroin users inject water (sometimes done deliberately to alleviate cravings when drugs are in short supply), they can experience drug-like euphoria and have been observed to show opiate-like physiological signs such as pupil constriction.

Headline o' the day

Designer vagina trend 'worrying'

The role of dopamine in drug addiction and Parkinson's

New research from Northwestern University's Feinberg School of Medicine has revealed that dopamine strengthens and weakens the two primary circuits in the brain that control our behavior. This provides new insight into why a flood of dopamine can lead to compulsive, addictive behavior and too little dopamine can leave Parkinson's patients frozen and unable to move.

"The study shows how dopamine shapes the two main circuits of the brain that control how we choose to act and what happens in these disease states, " said D. James Surmeier, lead author and the Nathan Smith Davis Professor and chair of physiology at the Feinberg School. The paper was published in the Aug. 8 issue of the journal Science.

Why doctors wear green or blue scrubs

According to Susannah Locke at Scienceline, surgeons in particular benefit from the colors green or blue as opposed to white for two reasons:

First, looking at blue or green can refresh a doctor’s vision of red things, including the bloody innards of a patient during surgery. The brain interprets colors relative to each other. If a surgeon stares at something that’s red and pink, he becomes desensitized to it. . . .

Second, such deep focus on red, red, red can lead to distracting green illusions on white surfaces. These funky green ghosts could appear if a doctor shifts his gaze from reddish body tissue to something white, like a surgical drape or an anesthesiologist’s alabaster outfit. A green illusion of the patient’s red insides may appear on the white background. . . . The distracting image would follow the surgeon’s gaze wherever he looks, similar to the floating spots we see after a camera flash.

The phenomenon occurs because white light contains all the colors of the rainbow, including both red and green. But the red pathway is still tired out, so the red versus green pathway in the brain signals “green."

The Tanganyika Laughter Epidemic of 1962

An interesting report by Discovery's Jennifer Viegas on the "Dancing Plague" of 1518 (often attributed to ergotism) discusses the possible psychological roots of this mass behavioral phenomenon. Also mentioned was a more modern variety of psychogenic  disorder -- an epidemic of hysterical laughter originating in a Tanzanian boarding school:

Perhaps the most unusual documented case of mass psychogenic illness was the Tanganyika Laughter Epidemic of 1962. A paper published the following year in the Central African Journal of Medicine described what happened.

Triggered by a joke among students at a Tanzania boarding school, young girls began to laugh uncontrollably. At first there were spurts of laughter, which extended to hours and then days.

The victims, virtually all female, suffered pain, fainting, respiratory problems, rashes and crying attacks, all related to the hysterical laughter. Proving the old adage that laughter can be contagious, the epidemic spread to the parents of the students as well as to other schools and surrounding villages.

Eighteen months passed before the laughter epidemic ended.

Is that a watermelon or are you just glad to see me?

Ananova reports:

Fresh watermelon has a similar effect to taking Viagra, according to scientists.

But men would have to eat at least six slices to have the same effect as one Viagra tablet - and it's not as 'organ-specific'.

Watermelons contain an ingredient called citrulline that can trigger production of a compound that helps relax the body's blood vessels, similar to what happens when a man takes Viagra.

Found in the flesh and rind of watermelons, citrulline reacts with the body's enzymes when consumed in large quantities and is changed into arginine, an amino acid that benefits the heart and the circulatory and immune systems.

"Arginine boosts nitric oxide, which relaxes blood vessels, the same basic effect that Viagra has, to treat erectile dysfunction and maybe even prevent it," said Bhimu Patil, director of Texas A&M University's Fruit and Vegetable Improvement Centre.

"Watermelon may not be as organ-specific as Viagra, but it's a great way to relax blood vessels without any drug side effects."