Notes from the book
https://youtu.be/5MuIMqhT8DM
Caffeine, Jet Lag and Melatonin
- An adult’s owlness or larkness, also known as their chronotype is strongly determined by genetics.
- Our 24-hour circadian rhythm determines wake and sleep cycle.
- While we are awake, a chemical called adenosine gets built up in our brain. It’ll continue to increase in concentration with every single waking minute. One consequence of increasing adenosine in the brain is an increasing desire to sleep.
- Caffeine - artificially mute sleep signal of adenosine, by making us more alert and awake.
- Caffeine is second most traded commodity after oil. It is widely used as psychoactive stimulant in the world.
- Caffeine works by successfully battling with adenosine for the privilege of latching on to adenosine receptors. Caffeine inactivates receptors, acting as a masking agent. It’s equivalent of sticking our fingers in your ears to shut out a sound.
- Caffeine has an average half-life of five to seven hours. Half-life refers to length of time it takes for the body to remove 50% of drug’s concentration.
Matthew Walker’s TED talk on sleep ⬇ was a trending, views nearing 7M.
Defining and Generating Sleep
- NREM sleep - Non-rapid Eye Movement sleep; REM sleep - Rapid Eye Movement
- NREM sleep - Dominates early in night. Weeds out and removes unnecessary neural connection. Helps transfer and makes safe newly learned information into long-term storage.
- REM sleep - Prevails later in night. Dreaming stage. Strengthens connections between neurons. Collides freshly minted memories with entire back catalog of our life’s autobiography.
- If you wake up earlier, you compromise REM sleep - forming memory will be impacted.
- If you sleep late at night, it affects NREM sleep - getting rid of toxins/unnecessary neural connection gets impacted.
- Evolution outlaws muscle activity during REM sleep - thereby prevents acting out on our dream experience.
Ape Beds, Dinosaurs, and Napping with Half Brain
- Its discovered that very simplest forms of unicellular organisms that survive for periods exceeding 24 hours, such as bacteria, have active and passive phases that correspond to the light-dark cycle of our planet. It is believed this is precursor of our own circadian rhythm.