Page 348 - Color_Atlas_of_Physiology_5th_Ed._-_A._Despopoulos_2003

A. Circadian rhythm generator in suprachiasmatic nucleus (SCN)
A . Circadian rh y thm gener a t o r in supr ac hiasmatic nuc l eus (SCN)
1 CL OCK
1 Genetic feedbackGenetic feedback
CLOCK
e
loop in SCN c

lls
loop in SCN cells PER1 1
P
E
R
A
P
t
o
S
m
(oscillator) r ) PAS motif i f
t
(
o
a
c
s
o
l
l
i
E
R
P
BMAL1
BMAL1 PER2 2 P PER3 3
R
E
Translation
a
ansl
r
T
tion
tion
T Transcription
anscrip
r
N
R RNA A
e
p per 1 1
r
E
E-box x Sleep–Wake Cycle, Circadian Rhythms
-bo
r
e
p
N
o
e
u
r
Neuron n per 2 2
E
-bo
o
of SCN E-box x
f
S
C
N
r
per 3 3
p
e
Eff
t
or
s
yst
e
ms
ec
-bo
E-box x 4 4 Effectorsystems
E
in CN
in CNS S
Intracellular
In trac e llul ar ? ?
– –

Cl concentration n
l
C
c
a
r
t
o
i
t
n
o
c
n
e
e
o
r
t
e
N Neocortex x
c
o
e
b
e
e
Z
2 2 Zeitgeber r Membrane Hypo- - T Thalamus s
g
t
i
y
o
mbrane
H
Me
p
a
a
m
u
h
l
th
u
al
am
potential
Bright light po t e n ti al thalamus s Plate 12.13
Bright light
t
c
e
tin
e
a
,
R Retina, etc. .
lee
p
Sleep- -
S
w wake e
a
k
CRH
CRH
m
r
t
h
y
h
rhythm
C
Core e
o
r
i
Melatonin n temperature r e
M
t
a
n
o
e
l
t
r
u
e
e
a
t
p
m
e
i
t
c
e
r
o
s secretion n 5 5
Circadian rhythms of: f :
thms o
an rh
Circadi
y
C
H
s
R
e
c
o
t
r
e
i
–
– CRH secretion n
u
e
r
t
e
m
r
e
t
a
p
o
r
–
C
e
e
C

o
l
u
p
3 3 Coupled d – Core temperature, ,
B
e c
y
le (see
c
-wak
lee
p
– S
s
oscillators in SCN – Sleep-wake cycle (see B), ),
t
s in SCN
or
c
ll
i
a
o
etc.
e t c .
y
e c
ak
-w
c
B B. Circadian rhythm of sleep-wake cycle e
. Circadian rh
y
thm of sleep
l
6:00 a.m.
6:00 a.m. 12:00 p .m. 6:00 p .m. 12:00 a.m. 6:00 a.m. 12:00 p.m. 6:00 p.m.
12:00 p
12:00 p.m.
.m.
12:00 a.m.
.m.
6:00 p
6:00 p.m.
6:00 a.m.
s
R Rest t T Time
e
ime
c
tivit
y
Activity
A
Normal Normal
1 1 3 3
Without external Without external zeitgeber zeitgeber 11
5 5
7 7
9 9
11
13
13
Days s
a
y
D
12-hour time shift
12-hour time shif t
a
d
in 12
y
in 12days: s : 335
25 -hour c ircadi an pe riods
25-hour circadian periods
c
f
o
h
t
e
f
( (After Aschoff) f )
A
s
A
r
Despopoulos, Color Atlas of Physiology © 2003 Thieme
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