This Is Your Brain on Psychedelics

September 4, 2026

AI Summary

5 min read

In 1938, Albert Hofmann synthesized LSD and had a hunch it did more than stimulate circulation. He took what he estimated to be a small dose — roughly the equivalent of 250 hits of acid — and rode his bicycle home. That day launched a molecule that neuroscientist Gül Dölen now argues is part of a much larger story: psychedelics, she has found, can reopen the brain's "critical periods," windows of heightened learning and flexibility that normally close after childhood. On this episode of StarTalk, Dölen explains the mechanism, the risks, and why the octopus on MDMA is a better experiment than it sounds.

Critical Periods and the Master Key

Critical periods are time-limited windows during development when the brain is especially receptive to learning specific things — language, social attachment, motor skills. First described by Konrad Lorenz in 1935 (baby geese imprint on whatever moves near them in the first 48 hours), these windows close because the brain becomes less plastic, trading flexibility for efficiency. As Dölen puts it, "If there was a saber-tooth tiger running around, you'd be done" if everyone experienced the world as inefficiently as a two-year-old.

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What you'll learn

1 (02:54) **Welcome & Guest Introduction** - Neil deGrasse Tyson, Gary O’Reilly, and Chuck Nice introduce guest Dr. Gül Dölen, a neuroscientist from UC Berkeley who studies psychedelics, neuroplasticity, and octopuses.
2 (08:15) **Animals, Traditional Medicine, and the Origins of Psychedelic Use** - Dr. Dölen explains that animals likely discovered psychoactive substances first, and traditional cultures used psychedelics as medicines, not just for recreation.
3 (10:27) **Albert Hofmann’s Accidental Discovery of LSD** - The story of LSD’s synthesis and Hofmann’s famous bicycle ride after taking an enormous dose.
4 (12:47) **Critical Periods Explained** - Dr. Dölen defines critical periods and connects them to her octopus research with MDMA.
5 (13:12) **Octopuses on MDMA: The Surprising Social Experiment** - Dr. Dölen describes how giving MDMA to normally asocial octopuses made them social and affectionate.
6 (15:34) **How MDMA Works Differently from SSRIs** - A clear breakdown of the molecular mechanism distinguishing MDMA from antidepressants like Prozac.
7 (21:18) **Common Mechanisms Across Different Psychedelics** - Dr. Dölen explains how various psychedelics (ketamine, psilocybin, LSD, MDMA, ibogaine) share a downstream unifying mechanism despite different initial receptor targets.

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Show Notes

What if you could reopen your childhood brain? Neil deGrasse Tyson, Chuck Nice, and Gary O’Reilly explore the cutting edge of psychedelic science, critical periods, and what a high octopus can teach us about the human mind with neuroscientist and psychedelics expert Gül Dölen.

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Thanks to our Patrons Edward Tuten, CJP, David Williamson, Shelsea Evans, Curious1, brittanivstheworld, Mark Huth, Annmarie Pine, Austin Wiggins, John Sprot, T.C. Polk, David Rossi, Murat Tahtali, Levi Jackson, Jeff L Kelly, Average Joe Paracord, gert alex, Ruthanne, joe, Arash Ghorbani, Fretbuzz Lightyear, Cody Asbury, Doyle Vann, APwater, Daniel Baker, K, Adam Boyher, Thom@0, Michael D Saladino, Cyrus Niccore, Lance W Roberts, Merix Style, Serhii Rieznik, slowbrow, Kamil Ignatowski, Dustin DeRollo, Jake Spector, Teemu Rönkkö, Kamron Barker, Chris Michel, Lee Patrick Anderson, Adam Deeb, Joshua10902, Arash Mehrnama, Juliejon Rondeau, Nickolaos Podias, Alex Seymour, Robert Harwood, William Ridout, Enck, Ryan Robertson, Fi Higgins, Roger Wacker, Bryce Weicht, Max, Burgai Atal, Misselvira, Kangee Gold, Bill Beauregard, and Jim Derych for supporting us this week.

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