Sleep

Summary and Support

• A study that examines the impact of normal sleep on auditory declarative memory among adolescents demonstrates the following:
  • An increase of 20.6% in declarative memory was observed among the subjects who procured sleep (as opposed to those who did not) prior to completing declarative and controlling memory tasks the following morning.
  • While the subjects’ declarative memory was enhanced, the control working memory did not show any significant improvement (compared to the working memory of those who did not procure sleep)
• Additionally, another research conducted on sleep indicates the following:
  • Each phase of sleep is characterized by certain cellular, anatomic and chemical events essential for proper neural functioning.
  • Various types of sleep deprivation (such as total sleep deprivation, sleep disruption and sleep restriction) may engender distinct obstacles to cognitive functioning.
  • The study of the effects of sleep deprivation on the brain suggests that two nights of total sleep can restore the behavioral deficits ensuing sleep deprivation.
  • However, at the same time, some findings from experiments on mice imply that chronic restriction or long-term sleep deprivation may give rise to neurodegenerative diseases such as dementia or Alzheimer’s.
• A study on the energy levels of the brain during sleep indicates the following:
  • In the wake-active brain regions of rats, the energy currency of brain cells or ATP levels, surge during the initial period of spontaneous sleep.
    • However, the phenomenon does not transpire in the rats’ sleep active brain regions.
  • Gently handling rats for three or six hours to prevent their sleep, prevents this ATP surge.
    • This suggests that the surge in the wake-active brain regions is not dependent on time of day.
  • In spontaneous sleep, EEG non-rapid eye movement delta activity was positively correlated with the ATP surge.
  • Infusing adenosine into the basal forebrain to induce sleep as well as delta activity within normally active dark periods also raises ATP.
  • The observations imply that reduced neuronal activity is accompanied by a rise in ATP.
  • Additionally, the P-AMPK reduction which coincides with the ATP surge during the sleep induced periods seems increase anabolic processes and reveal molecular occurrences (which induce biosynthetic processes which cause restoration) during sleep.

Contributors

Ayesh Perera