Dec 25, 2023
The Body, Not the Brain, Regulates Sleep
Posted by Arthur Brown in categories: genetics, neuroscience
Genetic screens have revealed three peripheral tissue genes that regulate sleep. What does this mean for sleep research?
Genetic screens have revealed three peripheral tissue genes that regulate sleep. What does this mean for sleep research?
Cortical gradient mapping stands as an innovative analytical tool for exploring the brain’s functional-spatial organization along a continuous spectrum28,29,30, distinguishing it from conventional techniques reliant on discrete boundaries, e.g., functional parcellation in neuroimaging. As an intuitive metaphor, consider defining a geographic region by its boundary coordinates, which is akin to functional parcellation, versus describing it by elevation slopes or changes in vegetation types across various topographical axes, which is similar to gradient mapping. These cortical gradients span a wide spectrum of functions and networks, ranging from perception and action to higher-order cognitive processes28. Notably, Gradient-1, known as the unimodal to transmodal gradient, enables the integration of sensory signals with non-sensory data, transforming them into abstract content. Gradient-2, the visual to somatomotor gradient, represents the specialization of different sensory modalities. Lastly, Gradient-3 spans functional distinctions ranging from regions typically deactivated during task performance (i.e., task-negative) to those activated in frontoparietal and attention networks (i.e., task-positive)31,32. Despite promising foundations, the potential of gradients as a framework for analyzing and conceptualizing non-ordinary states of consciousness induced by psychedelics remains ripe for exploration.
In addition to the brain’s functional geometry, dynamic processes continuously mold and reconfigure functional arrangements, leading to the evolution of brain activity patterns over time33,34. Recent empirical investigations have highlighted the intricate interplay between the spatial and temporal characteristics of brain activity, emphasizing that a comprehensive understanding necessitates the consideration of both aspects. Notably, transient fMRI co-activations33,35,36 spanning the entire cortex have been observed to propagate like waves, following the spatially defined cortical gradients37,38,39. Consequently, temporal dynamics are likely to be influenced by the underlying functional geometry. Exploring the co-variation between these spatial and temporal factors holds the potential to offer deeper insights into the neural underpinnings of psychedelic effects.
The objective of this study was to apply advanced cortical gradient mapping and co-activation pattern analysis to dissect the brain’s spatiotemporal reconfiguration during the psychedelic experience induced by nitrous oxide. Building upon previous research findings16,25, we tested the hypothesis that nitrous oxide could diminish functional differentiation within the human cortex, as evidenced by a contraction in functional geometry and a disruption in temporal dynamics. We reanalyzed a neuroimaging dataset of healthy human volunteers, who were assessed by fMRI before and during exposure to psychedelic concentrations of nitrous oxide (35%, in oxygen) and who completed a validated altered states of consciousness questionnaire40 before and after drug exposure. We quantified the changes of neural activity in cortical gradients and co-activations; we also performed correlation analyses to explore the relationship between subjective psychedelic experience and these brain measures. We demonstrate that nitrous oxide flattens the functional geometry of the cortex and disrupts related temporal dynamics, particularly within the frontoparietal and somatomotor networks, in association with the psychedelic experience.
Robert Sapolsky is one of the world’s leading neuroscientists, with a focus on the physiological effects of stress. (For years, he spent his summers in Kenya, alone except for the baboons he was observing.) Steve asks Robert why we value human life over animals, why he’s lost faith in the criminal justice system, and how to look casual when you’re about to blow-dart a very large and potentially unhappy primate.\
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This episode was originally published March 5, 2021.\
For a full transcript, resources, and more, visit: https://freak.ws/3WQAjmF\
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ABOUT PEOPLE I (MOSTLY) ADMIRE:\
People I (Mostly) Admire is hosted by Steven Levitt, the unorthodox University of Chicago economist and co-author of the Freakonomics book series, who tracks down other high achievers and asks questions that only he would think to ask. Guests include all-time Jeopardy! champion (and now host) Ken Jennings, YouTube C.E.O. Susan Wojcicki, W.N.B.A. champion Sue Bird, Operation Warp Speed chief Moncef Slaoui, and neuroscientist/actress (also now Jeopardy! host) Mayim Bialik. Winner of Adweek‘s 2021 Best Interview Podcast of the Year.\
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SUBSCRIBE TO PEOPLE I (MOSTLY) ADMIRE:\
YouTube: https://freak.ws/3yIl6dl\
Stitcher: https://freak.ws/3ENOP8v\
Apple Podcasts: https://freak.ws/3ELfGST\
Spotify: https://freak.ws/3D6uqKV\
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ABOUT FREAKONOMICS RADIO NETWORK:\
Freakonomics began as a book, which led to a blog, a documentary film, more books, a pair of pants, and in 2010, a podcast called Freakonomics Radio. Hosted by Stephen J. Dubner, it’s one of the most popular podcasts in the world, with a reputation for storytelling that is both rigorous and entertaining. Its archive of more than 500 episodes is available, for free, on any podcast app, and the show airs weekly on NPR stations. Freakonomics Radio is now the flagship show of the Freakonomics Radio Network, which includes the podcasts No Stupid Questions (est. 2020), People I (Mostly) Admire (2020), and Freakonomics, M.D. (2021). \
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FREAKONOMICS RADIO NETWORK PODCASTS:\
Freakonomics Radio: https://freakonomics.com/series/freak…\
No Stupid Questions: https://freakonomics.com/series/nsq/\
People I (Mostly) Admire: https://freakonomics.com/series/peopl…\
Freakonomics, M.D.: https://freakonomics.com/series/bapu/\
Special series: https://freakonomics.com/topics/\
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00:00 Robert Sapolsky bio\
01:37 Baboon research in Kenya\
3:03 Baboon social rank and health\
4:14 Blow-dart sedation challenges\
7:40 Why human and animal stress are similar\
11:09 Why Sapolsky only studied male baboons\
12:42 Affiliation vs. rank in baboons\
14:08 Tragic end of research with first baboon troop\
17:38 Why humans prioritize human lives\
19:25 How humans prioritize pets\
19:47 Prioritization of tigers in India\
21:00 Harambe the gorilla\
22:19 Chronic stress research\
25:08 Ways to respond to stress\
26:00 Genetic influence on stress\
26:45 ACE score to quantify stress\
28:49 Addressing PTSD to reduce crime\
29:35 Behave-Sapolsky book on violence\
29:56 Free will and violence\
30:35 Abolishment of criminal justice system\
30:54 The frontal cortex and impulse control\
31:31 Frontal cortex trauma in death row inmates\
32:29 Purposes of punishment\
32:46 Retribution\
32:59 Incapacitation and deterrence\
33:35 Quarantine model of punishment\
34:10 “Biological luck” in blame and reward\
34:51 Epilepsy, schizophrenia, and dyslexia misunderstood\
37:06 How to be a better storyteller.
Breaking link between early, late stages of disease may prevent dementia.
Alzheimer’s disease has plagued one large Colombian family for generations, striking down half of its members in the prime of life. But one member of that family evaded what had seemed would be fate: Despite inheriting the genetic defect that caused her relatives to develop dementia in their 40s, she stayed cognitively healthy into her 70s.
Study Reveals Protective Gene Mutation
For most adults, the majority of waking daily life is spent at work. That offers employers an opportunity to influence their employees’ physical, mental, social, and spiritual health.
To support the move to better health, the McKinsey Health Institute (MHI), along with other organizations such as the World Health Organization (WHO), are highlighting a more modern way to view health beyond illness and its absence.1 Adding years to life and life to years, McKinsey, March 29, 2022; A 2022 MHI survey on global health perspectives found that more than 40 percent of respondents who reported having a disease still perceived their health as good or very good, while more than 20 percent of those who reported no disease said they were in fair, poor, or very poor health. Embracing the concept of holistic health—an integrated view of an individual’s mental, physical, spiritual, and social functioning2 Previous work from MHI has defined each dimension of health in detail. For more details, see Adding years to life and life to years. Using this definition means that we emphasize “functioning.
This interview is an episode from @The-Well, our publication about ideas that inspire a life well-lived, created with the @JohnTempletonFoundation.
Watch Lisa Feldman Barrett’s next interview ► • The biggest myths about emotions, deb…
Continue reading “Your brain doesn’t detect reality. It creates it. | Lisa Feldman Barrett” »
MIT brain and cognitive sciences webinar.
Primates are among the most intelligent creatures with distinct cognitive abilities. Their brains are relatively large in relation to their body stature and have a complex structure. However, how the brain has developed over the course of evolution and which genes are responsible for the high cognitive abilities is still largely unclear. The better our understanding of the role of genes in brain development, the more likely it will be that we will be able to develop treatments for serious brain diseases.
Researchers are approaching these questions by knocking out or activating individual genes and thus drawing conclusions about their role in brain development. To avoid animal experiments as far as possible, brain organoids are used as an alternative. These three-dimensional cell structures, which are only a few millimeters in size, reflect different stages of brain development and can be genetically modified. However, such modifications are usually very complex, lengthy and costly.
Researchers at the German Primate Center (DPZ)—Leibniz Institute for Primate Research in Göttingen have now succeeded in genetically manipulating brain organoids quickly and effectively. The procedure requires only a few days instead of the usual several months and can be used for organoids of different primate species. The brain organoids thus enable comparative studies of the function of genes at early stages of brain development in primates and help to better understand neurological diseases.
Thanks in part to Elon Musk, the field of brain-computer interfaces has captured both public and investor interest, with a cadre of companies now developing implantable devices.