scholarly journals Ultradian Rhythms Underlying the Dynamics of the Circadian Pacemaker

10.5772/24868 ◽  
2011 ◽  
Author(s):  
Carolina Barriga-Montoya ◽  
Pablo Padilla-Longoria ◽  
Miguel Lara-Aparicio ◽  
Beatriz Fuentes-Pardo
Keyword(s):  
Circadian Pacemaker ◽  
Ultradian Rhythms

Nonphotic entrainment of the human circadian pacemaker

1998 ◽  
Vol 274 (4) ◽  
pp. R991-R996 ◽  
Author(s):  
Elizabeth B. Klerman ◽  
David W. Rimmer ◽  
Derk-Jan Dijk ◽  
Richard E. Kronauer ◽  
Joseph F. Rizzo ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Light Exposure ◽  
Core Body Temperature ◽  
Biological Clock ◽  
Bright Light ◽  
Circadian Pacemaker ◽  
Temperature Rhythms ◽  
Blind Individuals ◽  
Nonphotic Entrainment ◽  
Core Body

In organisms as diverse as single-celled algae and humans, light is the primary stimulus mediating entrainment of the circadian biological clock. Reports that some totally blind individuals appear entrained to the 24-h day have suggested that nonphotic stimuli may also be effective circadian synchronizers in humans, although the nonphotic stimuli are probably comparatively weak synchronizers, because the circadian rhythms of many totally blind individuals “free run” even when they maintain a 24-h activity-rest schedule. To investigate entrainment by nonphotic synchronizers, we studied the endogenous circadian melatonin and core body temperature rhythms of 15 totally blind subjects who lacked conscious light perception and exhibited no suppression of plasma melatonin in response to ocular bright-light exposure. Nine of these fifteen blind individuals were able to maintain synchronization to the 24-h day, albeit often at an atypical phase angle of entrainment. Nonphotic stimuli also synchronized the endogenous circadian rhythms of a totally blind individual to a non-24-h schedule while living in constant near darkness. We conclude that nonphotic stimuli can entrain the human circadian pacemaker in some individuals lacking ocular circadian photoreception.

Mental Walking through a Complex Maze Influences Lateralized Ultradian Rhythms

1998 ◽  
Vol 87 (3) ◽  
pp. 1059-1074 ◽  
Author(s):  
Alfred Meier-Koll ◽  
Ulla Albrecht ◽  
Dirk Neuschwander
Keyword(s):  
Ultradian Rhythms ◽  
Complex Maze

scholarly journals Differential regulation of circadian pacemaker output by separate clock genes in Drosophila

2000 ◽  
Vol 97 (7) ◽  
pp. 3608-3613 ◽  
Author(s):  
J. H. Park ◽  
C. Helfrich-Forster ◽  
G. Lee ◽  
L. Liu ◽  
M. Rosbash ◽  
...  
Keyword(s):  
Clock Genes ◽  
Differential Regulation ◽  
Circadian Pacemaker
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