NMDA receptor antagonists

I've been doing some research on what causes out of body experiences. Scientists have done experienments giving people ketamine, which can cause out of body or Near Death Experiences. Ketamine is an NMDA receptor antagonist. It is beleived that when people have an OBE naturally there is a glutamate flood which then causes the body to release an endogeneous NMDA receptor antagonist to stop cell death.

I'm not sure what use this information is as of course ketamine is illegal for recreational use, and would probably be very dangerous anyway. But if there was some way to intentionally trigger a glutamate flood, which I theorize may happen during meditation occassionally and when trying to WILD because you are trying to silence your mind, (glutamate firing?) Then sometimes at least you suddenly find yourself seperating from your body, or think you are anyway, or enter a dream scene from the waking state. Could this be the same thing ketamine is causing. Perhaps, because you are in a waking state but not asleep, the glutamate is keeping building up, but you are preventing it from activating its receptors which eventually causes an endogeneous NMDA receptor to activate.

If there was just a more reliable way to activate the NMDA receptor or some natural safe one that would be great. From my research I have found that L-Theanine is a weak NMDA antagonist, and St. John's Wort is also a NMDA antagonist. I've had OBE's before after taking 200-400mg of Theanine, so it may help with WILD's and OBE's, especially if combined with meditation. This may be why the amino blend popular with some of glutamine/ theanine/ aspartic acid works with some people at least. You are causing glutamate buildup with the glutamine, and the theanine is partially blocking its receptors. This could inturn cause the body to release a more powerfull endogeneous antagonist.

However these don't work well for many people, so if anyone knows of anything else, please post.