Comment · Wed, December 12, 2012
(x-post from r/askscience) When people take MDMA, why do their eyes "roll" into the back of their head? What is up with the other symptoms? Empathy? Tracers?
Original post in this thread
entitude · 15 points
What causes some of the other signatory signs of ecstasy? Why do people see "tracers"? Why are colors bright and more impressive? Clenching the jaw/grinding teeth? Why do people's chin do the characteristic chatter, like how you react to extreme cold while at the same time your body is probably a little warmer than usual? Why does it feel so good to get not just warm but HOT? And, the strangest one I think, what is up with all the empathy?
(Any other interesting explanations of other "symptoms" that I can't think of right now would be appreciated!)
What they were answering
Toodlum · 85 points
Why do people see "tracers"? Why are colors bright and more impressive?
Partial agonism at the 5-HT2A receptors. These receptors are famously known as the 'classical' psychedelic receptors. It is widely accepted that 5-HT2A agonism is directly responsible for the visual effects of these drugs, and is thought to be the main contributor to MDMA's hallucinatory effects. Of note, MDA is a more potent agonist at 5-HT2A than MDMA and is often described as a "trippier" version of MDMA.
Edit: Colors are brighter specifically because MDMA causes mydriasis. Serotonin in itself has mydriatic properties.
Clenching the jaw/grinding teeth? Why do people's chin do the characteristic chatter, like how you react to extreme cold while at the same time your body is probably a little warmer than usual?
Chewing in itself is a process that is under the direct control of serotonin and dopamine. The first step in this process originates from serotonergic neurons in the raphe nucleus which send signals to the ventral tegmental area (VTA). The VTA is the origin of dopamine in the two most important dopamine pathways (the mesolimbic and mesocortical pathways). Once the signal reaches the VTA, dopamine takes over and relays the signal along the mesocortical pathway to the Prefrontal Cortex (PFC). The PFC plays a significant role in voluntary movement. And sufficient dopamine levels in the PFC…
u/MisterYouAreSoDumb
As an addition to this point, MDMA induces a release of extracellular glutamate in many regions of the brain. Because of this, one's calcium channels can become overexcited due to overactivation of the NMDA receptors. This instigates a cascading signal throughout various neurons in parts of the brain that control muscle movement. Taking magnesium as a voltage-dependent NMDA receptor antagonist, helps with bruxism greatly. I do find that it does not completely eliminate nystagmous, but does reduce it slightly.