L-Glycine for Insomnia? Options

[SoulSeeker]

A group of Japanese researchers are doing some interesting work on l-glycine supplementation as a treatment for insomnia. Any thoughts on the potential for this? There's no one else that I could find that's doing this research.

Also, I have the full text of their preliminary 2006 paper, but not the new 2007 one. I was wondering if anyone has access to this latter full journal article?
http://www.blackwell-synergy.com/doi/abs/1...25.2007.00262.x

Subjective effects of glycine ingestion before bedtime on sleep quality
Authors: INAGAWA, Kentaro; HIRAOKA, Takenori1; KOHDA, Tohru1; YAMADERA, Wataru2; TAKAHASHI, Michio3
Source: Sleep and Biological Rhythms, Volume 4, Number 1, February 2006 , pp. 75-77(3)

The effects of glycine on sleep quality were examined in a randomized double-blinded cross-over trial. The volunteers, with complaints about the quality of their sleep, ingested either glycine (3 g) or placebo before bedtime, and their subjective feeling in the following morning was evaluated with the St. Mary's Hospital Sleep Questionnaire and Space-Aeromedicine Fatigue Checklist. The glycine ingestion significantly improved the following elements: "fatigue", "liveliness and peppiness", and "clear-headedness". These results suggest that glycine produced a good subjective feeling after awakening from sleep.

Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes
Authors: Wataru YAMADERA, Kentaro INAGAWA, Shintaro CHIBA, Makoto BANNAI, Michio TAKAHASHI, Kazuhiko NAKAYAMA
Source: Sleep and Biological Rhythms 5 (2), 126-131, April 2007

In human volunteers who have been continuously experiencing unsatisfactory sleep, effects of glycine ingestion (3 g) before bedtime on subjective sleep quality were investigated, and changes in polysomnography (PSG) during sleep were analyzed. Effects on daytime sleepiness and daytime cognitive function were also evaluated. Glycine improved subjective sleep quality and sleep efficacy (sleep time/in-bed time), and shortened PSG latency both to sleep onset and to slow wave sleep without changes in the sleep architecture. Glycine lessened daytime sleepiness and improved performance of memory recognition tasks. Thus, a bolus ingestion of glycine before bedtime seems to produce subjective and objective improvement of the sleep quality in a different way than traditional hypnotic drugs such as benzodiazepines.

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

I find this interesting because there's new research (that's very hot, published in Nature) that implicates Glycine in sleep paralysis (your body automatically paralyzes itself during REM sleep so you don't act out your dreams). Here are some quotes:

http://www.nature.com/nature/podcast/v441/...2006-06-01.html

"Jun Lu: It's very interesting. So what we found is that three groups of neurons are activated in REM sleep. One group projects to the forebrain and those cells contain excitory neurotransmitters. So you can imagine, when these cells become activated they project to the forebrain and your brain becomes highly activated.

Chris Smith: So what's that, glutamate or something?

Jun Lu: It contains glutamate. And also there's another group of cells projects spinal cord and they also contain glutamate. But these cells don't project to the motor neuron directly. And they project to the interneuron. Those interneurons contain an inhibitory neurotransmitter, glycine.

Chris Smith: So that's the correlate of how you become paralysed during sleep.

Jun Lu: Exactly, so when these cells become activated you stimulate a glycine inhibitor in the neuron and that neuron shuts down the motor neuron, that's how you become paralysed."

http://www.nature.com/neuro/journal/v9/n6/...606-721.html#B3

"Neuronal recording studies in the cat and dog have identified a population of neurons in the medial medulla of the cat and dog that are active only during periods of muscle tone suppression14, that is, REM sleep and cataplexy. Stimulation of these cells suppresses muscle tone by release of GABA and glycine, and lesioning this region reduces the normal muscle tone suppression of REM sleep"

[euphoria]

Seeing how ketamine and other NMDA antagonists cause insomnia, this makes sense.