** **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!