^Nice. Hope you had a good time.
I'll add another perspective here...and this is not intended to sound confrontational or argumentative.
I wasn't a big fan of Dr. Strassman's book, but I understand the reasons for its widespread appeal...there are few things I enjoy more than speculating about the metaphysical and physical consequences of the psychedelic experience.
In my opinion the book is disappointing for a number of reasons. First of all, Strassman spends nearly half of the book lamenting the state of current research on psychedelics and the barriers to conducting research. While I'll admit that he battled a lot of adversity and ultimately persevered, I think one chapter would have been more than sufficient to sympathize with the guy. What I found most disconcerting, however, was the creeping sense that his brand of pseudoscience is one reason why psychs aren't gaining credibility as legitimate avenues of future research. This may not be true, but his magical pineal gland hypotheses have certainly not helped to bring psychedelic research back from its marginalized state. He proposes that endogenous DMT plays a pivotal role in mental illness, dreaming, alien-abduction, and near-death experiences...all physiologically improbable. These may have been workable hypotheses if proposed half a century ago. Above all, the hypothesis that forced me to seriously question his power of ratiocination is the hypothesis that the soul enters the body at 49 days after conception, which he supports by referencing a parallel between human development of the pineal gland and a statement in the Tibetan Book of the Dead -- Maybe Descartes was right after all and the pineal is the seat of the soul?
I won't argue that everything he claims is wrong, but current evidence indicates that (1) DMT is not solely produced in the pineal, and (2) DMT is not present at relevant concentrations to exert an effect on 5-HT2A receptors. There was a bunch of research on endogenous DMT and its possible role in psychosis in the 60s, which was ultimately fruitless. I admire Dr. Strassman's efforts nonetheless. Hopefully, his research will shed light on the role of endogenous DMT and pave the way for future research with these compounds.
As far as evolutionary history of the pineal gland, there are a few species of lizards that still have a parietal eye (probably the ancestral pineal gland), and it serves a similar function to other pineal glands with its primitive photoreceptor cells. The function appears to be regulation of the sleep/wake cycle as in humans. There are at most a few species of lizard that still have the primitive lens and retina. As evolution progressed, the two primary eyes formed connections with the pineal gland as it took up residence at the base of the forebrain allowing it to lose its photoreceptor functions. So yes, the cells do resemble photoreceptors, and it still regulates cycles, but this is not surprising. MAOI seems to be present there to tightly control the levels of serotonin (it is highly concentrated in the pineal), which allows it to also tightly control melatonin production. Demystified.
