Skin temperature & Sleep

(1)

Bart te Lindert, MSc

Dept Sleep & Cognition

Netherlands Institute for Neuroscience

European Society of Sleep Technologists

European Sleep Research Society

Paris, September 2012

(2)

Wake

Sleep

(3)

McGinty & Szymusiak (1990) Trends Neurosci 13 : 480-487

Sleep occurs at low core and elevated skin temperature

Does skin temperature affect Warm Sensitive Neurons in sleep related brain areas?

(4)

Is skin temperature involved?

The preoptic area

(POAH) is the most

activated area during

sleep.

Boulant & Hardy (1974) J Physiol 240 : 639-660 Khubchandani et al (2005) Neuroimage 26 : 29-35 0 5 10 15 20 25 37 38 39 40 41 42 Hypothalamic temperature (ºC) Firin g ra te (s p ik es/ sec. ) Neutral skin (37 ºC)

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Is skin temperature involved?

0 5 10 15 20 25 37 38 39 40 41 42 Hypothalamic temperature (ºC) Firin g ra te (s p ik es/ sec. ) Warm skin (42 ºC) Neutral skin (37 ºC) Cool skin (30 ºC)

Skin temperature is the

major determinant of

WSN activation in the

preoptic area!

(6)

Egan et al (2005) PNAS 102 : 5262-5267

Also in humans,

skin warming

activates the

hypothalamic area

(7)

Van Someren (2000) Chronobiol Int 17 : 313-354

But… core and skin

warming affect

sleep-type neuronal

activity in

many

sleep related brain

areas.

midbrain recticular formation

WAKE: high firing rate

SLEEP: low firing rate

posterior hypothalamus

preoptic area – ant. hypoth.

diagonal band (BF)

cerebral cortex

midline thalamic nuclei

WAKE: high firing rate

WAKE: low firing rate

WAKE: tonic mode

WAKE: desynchronization SLEEP: low firing rate

SLEEP: high firing rate

SLEEP: phasic burst mode

SLEEP: synchronization

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Sleep drive

Skin warming

Sleep

(9)

1. Effect of skin temperature on sleep

2. Sleep estimates from skin temperature

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1. Effect of skin temperature on sleep

2. Sleep estimates from skin temperature

time (hours)

Can we boost slow wave oscillations?

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• Unknown; we do know that oscillations:

–

are

facilitated

by

activation

of the hypothalamic

preoptic area

–

often

emerge

in the insula, if

inactivated

What causes

slow oscillations

?

Egan et al (2005) PNAS 102 : 5262-5267 Massimini et al (2004) J Neurosci 24 : 6862-6870 Murphy et al (2009) PNAS 106 : 1608-1613

(12)

Mild skin warming:

–

activates POAH

Mild skin warming:

–

deactivates the insula

Egan et al (2005) PNAS 102 : 5262-5267 Craig et al (2000) Nat Neurosci 3 : 184-190

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Skin temperature manipulation Polysomnography

Proximal

34.9 - 35.3

º

C (∆ 0.4

º

C )

Distal

de

activation of INSULA

activation of POAH

Raymann et al (2008) Brain 131 : 500-513

(14)

34.9 º

C

Reaching areas critical for

slow oscillations

?

Raymann et al (2008) Brain 131 : 500-513

35.3 º

C

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• Trivial? Self regulation of microclimate

• Requires intact comfort sensing

• Insomnia: diminished capability to judge

‘comfort’, ‘pleasantness’

Raymann & Van Someren (2008) Sleep 31 : 1301-1309

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• Pleasant:

skin warming when cold, skin cooling when hot

Dunn et al (2010), abstract, Human Brain Mapping, Barcelona

Orbitofrontal area essential to hedonic evaluation

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Reduced orbitofrontal gray matter density

correlates with severity of complaints

Structural MRI in insomnia

(18)

Structural MRI in healthy subjects

Stoffers et al (2012) Front Neur 3 : 105

Reduced orbitofrontal gray matter density

correlates with severity of complaints

(19)

1. Effect of skin temperature on sleep

–

Mild skin warming promotes sleep and slow

oscillations

–

Dimished comfort sensing in insomnia

–

Correlates with orbitofrontal gray matter density

2. Sleep estimates from skin temperature

Conclusion 1

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1. Effect of skin temperature on sleep

2. Sleep estimates from skin temperature

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• Actigraphy classification:

–

activity = awake, immobile = asleep

• Classification fails if:

–

activity during sleep, immobile during wake.

Temperature sleep estimates: optimizing actigraphy

(22)

Skin temperature fluctutates during sleep

Van Someren (2006) Progr Brain Res 153 : 309-324 Van Marken Lichtenbelt et al (2006) Physiol Behav 88 : 489 -497

(23)

• Can skin temperature help reduce false

actigraphic sleep/wake classification?

Estimate

sleep / wake

Verify

sleep / wake

Reduce false

classifications?

(24)

(25)

Adding skin temperature to actigraphic sleep classification

increases

reliability from 86

±

1 % to 96

±

1 %!

(26)

1. Effect of skin temperature on sleep

–

Mild skin warming promotes sleep and slow

oscillations

–

Dimished comfort sensing in insomnia

–

Correlates with orbitofrontal gray matter density

2. Sleep estimates from skin temperature

–

Actigraphic sleep estimates improve with the

addition of skin temperature

(27)

Acknowledgements

Altena et al (2010) Biol Psychiatry 67 : 182-185

Boulant & Hardy (1974) J Physiol 240 : 639-660

Craig et al (2000) Nat Neurosci 3 : 184-190

Dunn et al (2010), abstract, Human Brain Mapping, Barcelona

Egan et al (2005) PNAS 102 : 5262-5267

Khubchandani et al (2005) Neuroimage 26 : 29-35

Massimini et al (2004) J Neurosci 24 : 6862-6870

McGinty & Szymusiak (1990) Trends Neurosci 13 : 480-487

Murphy et al (2009) PNAS 106 : 1608-1613

Raymann et al (2008) Brain 131 : 500-513

Raymann & Van Someren (2008) Sleep 31 : 1301-1309

Stoffers et al (2012) Front Neur 3 : 105

Van Marken Lichtenbelt et al (2006) Physiol Behav 88 : 489 -497

Van Someren (2006) Progr Brain Res 153 : 309-324

Van Someren (2000) Chronobiol Int 17 : 313-354

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