TY - JOUR
T1 - Cryptochrome-dependent circadian periods in the arcuate nucleus
AU - Uchida, Hitoshi
AU - Nakamura, Takahiro J.
AU - Takasu, Nana N.
AU - Todo, Takeshi
AU - Sakai, Takayoshi
AU - Nakamura, Wataru
N1 - Publisher Copyright:
© 2015.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - The circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus is responsible for controlling behavioral activity rhythms, such as a free running rhythm in constant darkness. Rodents have several circadian oscillators in other brain regions including the arcuate nucleus (ARC). In specific conditions such as food anticipatory activity rhythms in the context of timed restricted feeding, an alternative circadian pace-making system has been assumed by means of circadian oscillators like the SCN. Despite extensive lesion studies, the anatomic locations of extra-SCN circadian pacemakers responsible for regulating behavioral rhythms have not been found. In the present study, we investigated circadian rhythms in the SCN and extra-SCN region of the arcuate nucleus (ARC) by analyzing PER2::LUCIFERASE expression in specific regions from wild-type C57BL/6, Cry1-/-, and Cry2-/- mice. Compared to wild-type animals, we observed period shortening in both the SCN and ARC of Cry1-/- mice and period lengthening in Cry2-/- mice. Interestingly, the periods in the ARC of both genotypes were identical to those in the SCN. Moreover, the amplitudes of PER2::LUC rhythms in the ARC of all animals were decreased compared to those in the SCN. These data suggest that the ARC is a candidate circadian pacemaker outside the SCN.
AB - The circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus is responsible for controlling behavioral activity rhythms, such as a free running rhythm in constant darkness. Rodents have several circadian oscillators in other brain regions including the arcuate nucleus (ARC). In specific conditions such as food anticipatory activity rhythms in the context of timed restricted feeding, an alternative circadian pace-making system has been assumed by means of circadian oscillators like the SCN. Despite extensive lesion studies, the anatomic locations of extra-SCN circadian pacemakers responsible for regulating behavioral rhythms have not been found. In the present study, we investigated circadian rhythms in the SCN and extra-SCN region of the arcuate nucleus (ARC) by analyzing PER2::LUCIFERASE expression in specific regions from wild-type C57BL/6, Cry1-/-, and Cry2-/- mice. Compared to wild-type animals, we observed period shortening in both the SCN and ARC of Cry1-/- mice and period lengthening in Cry2-/- mice. Interestingly, the periods in the ARC of both genotypes were identical to those in the SCN. Moreover, the amplitudes of PER2::LUC rhythms in the ARC of all animals were decreased compared to those in the SCN. These data suggest that the ARC is a candidate circadian pacemaker outside the SCN.
KW - Arcuate nucleus
KW - Behavioral activity
KW - Circadian rhythm
KW - Clock genes
KW - Suprachiasmatic nucleus
UR - http://www.scopus.com/inward/record.url?scp=84946600825&partnerID=8YFLogxK
U2 - 10.1016/j.neulet.2015.10.071
DO - 10.1016/j.neulet.2015.10.071
M3 - 学術論文
C2 - 26542738
AN - SCOPUS:84946600825
SN - 0304-3940
VL - 610
SP - 123
EP - 128
JO - Neuroscience Letters
JF - Neuroscience Letters
ER -