PowerPoint Presentation

Sleep and Wakefulness (and Circadian Rhythms)

What is Sleep? Minimal Behavioral Activity

A rapidly reversible state of quiescence

Increased Arousal Threshold

Species-Specific PostureTobler and Stadler, 1988

Measurement of Sleep

Two Types of SleepNon-rapid eye movement (NREM) sleepFour different stages (1 [lightest] 4 [deepest])Mixed-frequency EEGlow amplitude, high voltage or high amplitude, low voltageRelatively little muscle movements

Rapid eye movement (REM) sleepLow-amplitude, high voltage EEGSynchronous eye movementshttp://www.youtube.com/watch?v=AZ6I9N7t7VcParalysisNarcolepsy: http://www.youtube.com/watch?v=nvMyuZKGKAY

Brain-Spinal Cord Induction of Paralysis During REM sleep

Time Course of Sleep

Ontogeny of Sleep

Neural Control of Sleep

Neural Control of (NREM) Sleep

Bottom-Up ProcessingFlip-Flop CircuitCliff Saper, Bob McCarley, Jerome Siegel

Neural Control of (REM) SleepPGO waves pons-geniculate-occipital areas ORBrainstem-Thalamus-Occipital Cortex

Neural Control of Spindles

Really Cool Probing of Sleep-Regulatory Areas With Optogenetics

Circadian Rhythms

Basic Criteria of Circadian RhythmsAny physiological or behavioral process that oscillates predictably across 24 hrsThis rhythm can be shifted by environmental factors (light, drugs, mating)Persist even with the removal of environmental triggers (light, seasons)Some Out-of-Phase Physiological Rhythms

Rhythms in HumansNathaniel Kleitman and Eugene Aserinsky

Neural (SCN) Control of Rhythms

SCN: Suprachiasmatic NucleusBeyond the SCN: Molecular Control of Rhythms

Real-Time Recording of Molecular Feedback in the SCN

Working in TandemInteraction between sleep and circadian brain systems characterized as the two-process model

More Questions?You can stop by for a lab visit