DXM is, or at least appears to be inactive in me. I have tried both syrup (several time, the most it did, was one of those time, give me blurred vision and intense nausea, and motor incoordination, resulting in me staggering into a bar, cursing like a drunken sailor on a meth comedown, and spraying the walls in the bathroom with lurid highlighter pen-pink chunky plastic.
Collapsed, got up after a while, and walked out again, I don't believe the proprietors were all too chuffed about that somehow.
Rest of the times, not even that, no effects, other than nausea and or praying to the muslim god...I mean, contents of the loo bowl, sorry.
Powder, absolutely no effects whatsoever.
As for the NMDAr connection, yes, I believe so. One can look at users of ketamine, or other glutamatergic dissociative drugs (the others sometimes classed as dissociative, mainly kappa opioid agonists and competitive GABAa agonists do not share this effect in my experience with either) Also backing it up, are those cases of anti-NMDAr encephalitis, a condition where the body starts creating antibodies targeted at the NMDA receptor. The result is striking to say the least. Incoordination, hearing voices, intense paranoia, hallucinations, seizure and psychotic ideation.
Never tried PCP, although I would quite like to, I enjoy dissociatives, at least the ones I have tried, i.e ket, diethyl ether, diisopropyl ether (orally and inhaled) and methoxetamine. DXM appears inert. I really like MXE though. I ordered some tiletamine quite a while back, and the order slipped through the cracks while the vendor had some payment processing issues. They are, however, sending me some extra to compensate for the delay, after I contacted them. I'm hoping it will arrive any day now. Quite looking forward to it. I did have the chance to try out some AP-4, but decided not to, after reading the words 'brain oedema' somewhere connected to it, and decided not to bother figuring out if that was due to concentrations used on the poor lab animals, and that 'brain oedema' was something that I wasn't going to have anything to do with finding out weather they were referring to NMDA antagonist neurotoxicity or something unique to the drug itself.
Bugger that, I don't need my head swelling. I KNOW I am perfect already, I don't need extra effort going towards convincing me of the fact.
Preaching not to the choir, but shoving a bible up the arse of the pope himself.
Sideways.
There are two hypotheses of schizophrenia, well, more, but two rather reductionist hypotheses, one based on overactive dopaminergic neurotransmission, the other on a hypofunctional NMDA glutamatergic system, both causing some common symptoms, with amphetamine and MK-801 being used experimentally to attempt to mimic the disorder in vivo in animal subjects (fucking monstrous cocksuckers need to get set on fire, skinned, an downed in KOH-saturated acetone that do such things to animals if you ask me, you didn't, but fuck that, I'll say it anyway)
Personally I reckon its a mixture of the two, plus some structural malformations neurologically speaking. But anyhow.....back on track..the social withdrawal, and hallucinations, particuarly, I believe, the auditory ones, have a lot in common, so it seems, with the effects of NMDA antagonists.
One of the last times I was on MXE, I noted the voices, and connected them with the fish bubbler, hard to make out, save for odd words here and there, some wierd visuals such as curtains/carpets of mist/fog that changed at times, to look almost like panes of glass, standing upright at angles to the viewpoint up close in front of me, true hallucinations, although unlike the fruitloop in mid-skitz, I knew they were merely a product of the drug, likewise, I could hear people I knew in the background out of the open window, although it was actually the little girls that live on my road (although I do know some of them, but I was hearing other people, some friends of mine, that could not have been there at the time), and voices in music, although to a lesser extent.
I thought at the time 'hhmm, this is quite reminiscent of how I read schizophreniform delusions to take form and how I have been told by people who are schizos they see/hear things'
As for weed...I don't believe THC has affinity for NMDAr antagonist activity...I need to find my copy of 'cannabinoids and the brain' again on whatever flash drive its on, an excellent book, I reccomend searching for it, I don't know the author, but the title should help find it, it has an excellent, very indepth look at CB1/CB2/other cannabinoid receptors such as CB3 and the effects on intracellular signalling, and enzyme activities of cannabinoids (surprise fucking surprise ey fuckers? there was me thinking it was going to be about the history of the roman cunting empire)
But bear in mind, that cannabinergic signalling mediated via CB1 receptors occurs in a retrograde manner, with postsynaptic synaptic terminals releasing endocannabinoids that diffuse over and activate CB1 receptors located presynaptically, which then act to inhibit neurotransmitter release, including glutamate, GABA (which despite tendency to decrease DA otherwise, thus acts to effect suppression of inhibition) Decreasing glutamate release all over, as well as affecting both kainate and AMPA type glutamate receptors, and the metabotropic GLuRs, includes, of course, the NMDAr.
Thusly, I find it logical that in some people, particularly those with a pronounced sensitivity to glutamatergic dissociatives may find THC induces a similar state.
Full agonist cannabinoids are apparently very heavily sedating, and quite dissociative in effects.
Only had something that matches that profile in a blend though, which was later found, at some times, to contain a mixture of JWH-018, one of the CP,55-series, and another, one of which was a full agonist at CB1. Produced effects quite unlike any other cannabinoid I have ever smoked, very, very dissociative and visual, although its only speculation.
I really want to try those two phenyl-(4,4,4)-trifluorobutylsulfonate cannabinoids myself, one of them is a full agonist at CB1, the other a fairly efficacious partial agonist. I wouldn't mind giving HU-211 a shot sometime also, although I have read a bioassay, by somebody who did, and it hit the guy like a ten ton truck to the back of the head dropped from a great height, and lasted over a day.