EP250: Micro-Awakening Throughout The Night

Welcome to my podcast. I am Doctor Warrick Bishop, and I want to help you to live as well as possible for as long as possible. I’m a practising cardiologist, best-selling author, keynote speaker, and the creator of The Healthy Heart Network. I have over 20 years as a specialist cardiologist and a private practice of over 10,000 patients. Podcast Summary Introduction Dr. Warrick Bishop, a cardiologist, author, and CEO of the Healthy Heart Network, hosts this episode to explore the counterintuitive relationship between sleep interruptions and sleep quality. With heart attacks occurring nearly every 10 minutes in Australia and affecting over 9 million people globally, Dr. Bishop is on a mission to improve health literacy and prevent cardiovascular disease through education on various health factors, including sleep. Key Takeaways: Brief awakenings during the night may actually indicate good sleep quality, contrary to the common belief that uninterrupted sleep is ideal. Noradrenaline, a stress neurotransmitter previously thought to be inactive during sleep, actively controls the microarchitecture of sleep and rises and falls in waves every 30 seconds. Microarousals (mini-wakes) triggered by noradrenaline peaks are linked to memory consolidation, helping the brain retain information from the previous day's experiences. The higher the noradrenaline peak during sleep, the longer the brief awakening, and the more noticeable it becomes to the sleeper. Sleep spindles—short bursts of brain activity occurring when noradrenaline drops—are directly linked to memory consolidation and learning. Mice with the deepest "valleys" (prolonged noradrenaline drops) followed by extended awakenings demonstrated the best memory retention in research studies. Humans naturally experience over 100 brief awakenings per night during non-REM stage two sleep, which is spindle-rich and essential for memory consolidation. Short awakenings during sleep may play a crucial role in the brain's glymphatic system, which cleans up waste products through a rinsing fluid system that's particularly active during sleep. While restless sleep is not beneficial, occasional brief awakenings appear to be a natural and necessary component of healthy sleep architecture and cognitive function.