Mind & Matter
Whether food, drugs or ideas, what you consume influences who you become. Learn directly from the best scientists & thinkers alive today about how your mind-body reacts to what you feed it.
The weekly M&M podcast features conversations with the most interesting scientists, thinkers, and technology entrepreneurs alive today.
Not medical advice.
At M&M, we are interested in trying to figure out how things work, not affirming our existing beliefs. We prefer consulting primary rather than secondary sources and independent rather than institutional voices. If we encounter uncomfortable truths or the evidence suggests unfashionable ideas may be valid, so be it.
As the host, my aim is to help you better understand how the body & mind work by curating & synthesizing information in a way that yields science-based insights that you can choose to use or disregard in your own life. Taking ownership of your health starts with taking ownership of your information diet.
I am motivated to connect the dots and distill general principles from what I learn, preferring to ask questions and play devil’s advocate to debating or incessantly pushing my own viewpoint.
My beliefs:
- Taking ownership of your health starts with taking ownership of your information diet.
- All knowledge is provisional and we must work hard to prevent ourselves from becoming attached to our favorite ideas & preferred conclusions.
- Wisdom comes from an iterative, trial-and-error process of learning and unlearning. Letting go of pre-conceived notions can be painful, but pain is information.
Sometimes modern discoveries teach us we must unlearn received wisdom. Other times, modern information overload & historical chauvinism cause us to forget ancient wisdom which stills applies. The framework for learning that I embody is inspired by three Ancient Greek maxims inscribed in the Temple of Apollo at Delphi:
- “Γνῶθι σεαυτόν” (Know thyself)
- “Μηδὲν ἄγαν” (Nothing in excess)
- “Ἐγγύα πάρα δ Ἄτα” (Certainty brings insanity)
Mind & Matter
The Claustrum: Cognition, Consciousness, Alcohol & Psychedelics | Episode 278
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The brain's mysterious claustrum region, its role in cognitive flexibility, and how substances like alcohol and psychedelics affect neural circuits and behavior. Not medical advice.
TOPICS DISCUSSED:
- Cerebral cortex structure: Described as a six-layered structure with pyramidal neurons and inhibitory interneurons; information flows between layers and regions to process sensory input and enable complex behaviors.
- Claustrum anatomy & connectivity: A sheet-like subcortical structure embedded in white matter, bidirectionally connected to cortical areas, especially prefrontal regions in rodents, with broader connections in primates and humans suggesting an integrative role.
- Claustrum function in cognition: Experiments show claustrum activation during task switches from easy to demanding modes, synchronizing cortical networks via inhibition and rebound excitation, potentially enabling flexible behavior.
- Mouse models in neuroscience: Mice are used for genetic tractability to manipulate and monitor specific circuits, revealing claustrum’s role in vigilance tasks but not simple ones.
- Alcohol’s effects on brain circuits: Chronic alcohol promotes inflexible behaviors by altering striatal interneurons and inhibitory inputs, leading to compulsive drinking despite aversive consequences.
- Psychedelics & brain networks: Psilocybin disrupts default mode and other networks, inhibits claustrum via serotonin 1B receptors, with effects persisting 24 hours, possibly contributing to therapeutic benefits.
- Evolution of claustrum: Connectivity expands from rodents to humans, shifting from cognitive-specific to broader network control, including anti-correlated states like default mode versus task-engaged.
- Integration of claustrum & basal ganglia: Claustrum funnels prefrontal signals to basal ganglia for action selection; alcohol may impair this, exacerbating inflexibility in addiction.
ABOUT THE GUEST: Brian, PhD is a professor in the Department of Pharmacology and Physiology at the University of Maryland School of Medicine, where he leads a neuroscience lab studying brain circuits underlying flexible and inflexible behaviors using mouse models, with a focus on alcohol use disorder.
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