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** **YAWN** **YAWN Sleep and its Restriction Sleep and its Restriction
A Brief Examination of Underlying Mechanisms and Results
Kait Scalisi
?Why Sleep ?Why Sleep
• Affects everyone• Required
• Deprivation effects are well-known
The Rundown The Rundown
• Normal Sleep– A Basic Introduction
• Circadian Rhythms• Adenosine Theory of
Sleep• Stages of Sleep
– A Closer Look: SWS and Sleep Intensity
• Sleep Restriction– What and How?– So What’s the Big
Deal?• College students• Business Executives• Lactating mothers
The Rhythm of the Night The Rhythm of the Night
• Pacemaker– Light/dark cycle
• Suprachiasmatic nucleus (SCN)– “Master” circadian clock– Collect inputs– Generate signals
• Retinohypothalamic tract (RHT)– Synchronization– Glutamate
• Autoregulatory feedback loop– Rhythmic transcription and
expression
?How Do You Sleep ?How Do You Sleep
• Homeostatic sleep drive– Sleepiness
• Sedative– Caffeine = antagonist
• Inhibitory– Basal forebrain– A1 receptor
– D2 and A2A
: Sleeping to Dream The Stages : Sleeping to Dream The Stages
Sleep Spindle
Delta Waves
, , SWS SWA NA, , SWS SWA NA
• Sleep intensity as a function of prior wakefulness– NREM Slow Wave Activity (SWA)
• LTP, NA, and SWA homeostasis– Increased synaptic load enhanced amplitude– Cirelli, Huber, Gopalakrishnan, Southard & Tononi
(2005)
• Circadian rhythms, sleep centers, the activation of the noradrenergic system, and the induction of LTP during wakefulness.
SurveySurvey
At least…
– 4 hours?
– 6 hours?
– 7 hours?
– 8 hours?
– More than 8 hours?
, . 1Losing Sleep Pt , . 1Losing Sleep Pt
• Acute vs chronic• Homeostatic vs
allostatic load– Importance of the
stress response
• Sleep intensity vs sleep latency– Only intensity
0
2
4
6
8
10
12
14
BL SR1 SR2 SR3 SR4 SR5 R1 R2 R3
Tim
e (
ho
ur)
18-h SD
6-h SO
24-h Total
50%
75%
100%
125%
150%
175%
BL SD1 SD2 SD3 SD4 SD5 R1 R2 R3% C
ha
ng
e fr
om
Ba
selin
e L
eve
l
18-h SD6-h SO
Total sleep time.
NREM EEG delta power.
, . 2Losing Sleep Pt , . 2Losing Sleep Pt
0%
50%
100%
150%
200%
BL SR1 SR3 SR5 R1 R3
β-AR0%
50%
100%
150%
200%
BL SR1 SR3 SR5 R1 R30%
50%
100%
150%
200%
0%
50%
100%
150%
200%
BL SR1 SR3 SR5 R1 R3
β-AR
• The role of NA– Inverse pattern of expression
• Activation of β-adrenergic receptor (β-AR) during deep sleep– Mediator?
Changes in β-adrenergic receptor mRNA.
I Need Sleep I Need Sleep
• Von Dongen, Maislin, Mullington, and Dinges (2003).– Dose-response CSR experiment– Waking neurobehavioral and sleep
physiological functions monitored– Even moderate chronic sleep restriction can
have a sizeable impact on cognitive performance
’ :I Don t Sleep ’ :I Don t Sleep College Students College Students
• Results from Van Dongen, et al. (2003) extremely worrisome
• Both TSD and CSR common• Usual means not effective• The Hawk article
– “A winless battle”
:Where Did You Sleep Last Night :Where Did You Sleep Last Night Business Executives Business Executives
“Frenzied corporate cultures still confuse
sleeplessness with vitality and high performance.”
“We now know that 24 hours without sleep or a week of sleeping four or
five hours a night induces an impairment equivalent to a blood alcohol level of .1%. We would never say,
‘This person is a great worker! He’s drunk all
the time!’ yet we continue to celebrate people who
sacrifice sleep.”
, , :Eat Sleep Repeat, , :Eat Sleep Repeat Lactating Mothers Lactating Mothers• Blyton, Sullivan &
Edwards, 2002 – Increased SWS– Decreased light NREM– Prolactin ?– "lactation and the
associated complex interaction of the neuroendocrine system"
Time spent in light NREM, SWS, and REM.
SWS during first and second half of the night
The Great Sleep The Great Sleep
• Every new answer leads to many more new questions.
• A true scientific enigma
• Highly impacting• Don’t wait until
you’re dead!