Sleep wake cycle in a human being
Access to Electric Light Is Associated with Shorter Sleep Duration in Toba Communities of The Argentinean Chaco Horacio O. de la Iglesia Eduardo Fernández-Duque
Norberto Lanza Diego A. Golombek
Jeanne F. Duffy Charles D. Czeisler and
Claudia R. Valeggia
Components of Mammalian Circadian System
Environmental Cycle (e.g.. light-dark cycle)
Photoreceptors (retina)
Clock (suprachiasmatic nucleus)
Input pathways
Output pathways
I IX
III VI
Overt circadian rhythms (e.g. sleep-wake cycle)
The circadian system is highly sensitive to light resetting Flying squirrels can be entrained by one second of light per day
one second!
The human circadian system can be reset by artificial light
Could our ancestral sleep timing
have changed by the access to artificial light, particularly electric light?
The Toba
Ingeniero Juárez, Argentina - Google Maps
https://maps.google.com/maps?f=q&source=s_q&hl=en&geoc...
Address Ingeniero Juárez Formosa Province, Argentina
You can enter notes here
Latitude: 23º 47min Longitude: 61º 48min
Activity data loggers
300 900 200 800 100 700 0 600
500
0
time 40 100 160 220 280 340 400 460 520 580 640 700 760 820 880 940 1000 1060 1120 1180 1240 1300 1360
500
12
0 80 160 240 320 400 480 560 640 720 800 880 960 1040 1120 1200 1280 1360
6000
12 time 40 100 160 220 280 340 400 460 520 580 640 700 760 820 880 940 1000 1060 1120 1180 1240 1300 1360
Locomotor activity
November (summer) 900
800
700
600
500
400
300 900 200 800
100 700
400
16
16 20
00 4 Clock time
00 4 8 Clock time Sunset Sunrise 20 8
12
400
300
200
100
12
November (summer)
Time in bed Sleep duration
Bedtime
Rise time
Sleep onset
Sleep offset
Rise time
Bedtime
Time in bed
NO-electricity
*
Sleep duration 1700 1300
Sleep onset
Sleep offset
Electricity
† 2200
0300
Clock time
0800
August (winter)
900 800
600
500 400 300 200 100 0 0 80 160 240 320 400 480 560 640 720 800 880 960 1040 1120 1200 1280 1360
Locomotor activity
700
12
16
20
00 4 Clock time
Sunset
8
Sunrise
12
August (winter)
Time in bed Sleep duration
Bedtime
Rise time
Sleep onset
Sleep offset
Rise time
Bedtime
Time in bed
NO-electricity
* Sleep onset
Sleep duration
Sleep offset
† 1700 1300
Electricity
¥
2200
0300
Clock time
0800
NO-electricity
Get up time
Bedtime
Time in bed
Sleep onset
Sleep duration
Sleep offset
Get up time
Bedtime
Time in bed
Sleep onset
Sleep offset
Sleep duration
2200
Summer
#
¥
1700 1300
Winter
0300
Clock time
0800
Electricity
Time in bed Sleep duration
Bedtime
Rise time
Sleep onset
Sleep offset
Rise time
Bedtime
Time in bed
Winter
* Sleep onset
Sleep duration
Sleep offset
Summer
¥
1700 1300
2200
0300
Clock time
0800
Acknowledgments
The Toba communities of Sombrero Negro and Barrio Qompi. Thank you for your friendship!
Norberto Lanza Diego A. Golombek
Jeanne F. Duffy Charles D. Czeisler and
Claudia R. Valeggia
Components of Mammalian Circadian System
Environmental Cycle (e.g.. light-dark cycle)
Photoreceptors (retina)
Clock (suprachiasmatic nucleus)
Input pathways
Output pathways
I IX
III VI
Overt circadian rhythms (e.g. sleep-wake cycle)
The circadian system is highly sensitive to light resetting Flying squirrels can be entrained by one second of light per day
one second!
The human circadian system can be reset by artificial light
Could our ancestral sleep timing
have changed by the access to artificial light, particularly electric light?
The Toba
Ingeniero Juárez, Argentina - Google Maps
https://maps.google.com/maps?f=q&source=s_q&hl=en&geoc...
Address Ingeniero Juárez Formosa Province, Argentina
You can enter notes here
Latitude: 23º 47min Longitude: 61º 48min
Activity data loggers
300 900 200 800 100 700 0 600
500
0
time 40 100 160 220 280 340 400 460 520 580 640 700 760 820 880 940 1000 1060 1120 1180 1240 1300 1360
500
12
0 80 160 240 320 400 480 560 640 720 800 880 960 1040 1120 1200 1280 1360
6000
12 time 40 100 160 220 280 340 400 460 520 580 640 700 760 820 880 940 1000 1060 1120 1180 1240 1300 1360
Locomotor activity
November (summer) 900
800
700
600
500
400
300 900 200 800
100 700
400
16
16 20
00 4 Clock time
00 4 8 Clock time Sunset Sunrise 20 8
12
400
300
200
100
12
November (summer)
Time in bed Sleep duration
Bedtime
Rise time
Sleep onset
Sleep offset
Rise time
Bedtime
Time in bed
NO-electricity
*
Sleep duration 1700 1300
Sleep onset
Sleep offset
Electricity
† 2200
0300
Clock time
0800
August (winter)
900 800
600
500 400 300 200 100 0 0 80 160 240 320 400 480 560 640 720 800 880 960 1040 1120 1200 1280 1360
Locomotor activity
700
12
16
20
00 4 Clock time
Sunset
8
Sunrise
12
August (winter)
Time in bed Sleep duration
Bedtime
Rise time
Sleep onset
Sleep offset
Rise time
Bedtime
Time in bed
NO-electricity
* Sleep onset
Sleep duration
Sleep offset
† 1700 1300
Electricity
¥
2200
0300
Clock time
0800
NO-electricity
Get up time
Bedtime
Time in bed
Sleep onset
Sleep duration
Sleep offset
Get up time
Bedtime
Time in bed
Sleep onset
Sleep offset
Sleep duration
2200
Summer
#
¥
1700 1300
Winter
0300
Clock time
0800
Electricity
Time in bed Sleep duration
Bedtime
Rise time
Sleep onset
Sleep offset
Rise time
Bedtime
Time in bed
Winter
* Sleep onset
Sleep duration
Sleep offset
Summer
¥
1700 1300
2200
0300
Clock time
0800
Acknowledgments
The Toba communities of Sombrero Negro and Barrio Qompi. Thank you for your friendship!
