Lecture Notes: The Importance of Sleep

Introduction

• 1965 Experiment by Randy Garner:
  • 17-year-old stayed awake for 264 hours (11 days) to test effects of no sleep.
  • Day-by-day Effects:
    • Day 2: Eyes stopped focusing.
    • Day 3: Lost ability to identify objects by touch, became moody and uncoordinated.
    • End: Struggled with concentration, short-term memory, paranoia, hallucinations.
  • Recovered without long-term damage, but highlights potential severe effects of sleep deprivation.

Importance of Sleep

• Essential for psychological and physical balance.
• Adults require 7-8 hours; adolescents need about 10 hours nightly.
• Sleep influenced by:
  • Body signals (tiredness)
  • Environmental cues (darkness)

Sleep Mechanics

• Non-REM Sleep:
  • Initiated by adenosine and melatonin.
  • Breathing, heart rate slow, muscles relax.
  • DNA repair and body replenishment occur.

Sleep Deprivation

• Prevalence:
  • 30% of adults and 66% of adolescents in the US are sleep deprived.
• Effects:
  • Impacts learning, memory, mood, reaction times.
  • Can cause inflammation, hallucinations, high blood pressure.
  • Linked to diabetes, obesity.
  • Example: 2014 soccer fan's death after 48 hours awake.

Extreme Cases

• Fatal Familial Insomnia:
  • Rare genetic mutation causing inability to sleep.
  • Leads to dementia and death over time.

Biological Explanation

• Waste Accumulation:

  • During wakefulness, energy use creates byproducts like adenosine.
  • Accumulation increases sleep pressure.
  • Caffeine blocks adenosine receptors.
  • Other wastes build up, leading to negative deprivation symptoms.

• Brain Cleanup:

  • Glymphatic System:
    • Removes brain's waste during sleep.
    • Uses cerebrospinal fluid to clear toxic byproducts.
  • Lymphatic Vessels:
    • Pathways for immune cells, possibly involved in waste clearance.

Conclusion

• Sleep is crucial for maintaining health and sanity.
• Ongoing research into sleep's restorative mechanisms.