How does serotonergic (5-HT2A specific) psychedelia work? I've read that there are some theories that it might involve the induction of a glutamate release in certain regions of the brain involved in perception.
Brenton, the linked pdf is called "Multiple receptors contribute to the behavioral effects of indoleamine hallucinogens". It goes into detail on a a few basic behavioral responses. I don't know what your background is so if you need help understanding parts point them out to me and I'll give it a go.
https://docs.google.com/file/d/0B0JUrCVOms3MdzdlYmh0SnBmOHc/edit (I'm hosting the pdf on my Google Drive if you aren't able to see the link hosted by the NIH).