| Autor: |
Usui, Setsuo, Okazaki, Terue, Honda, Yoshiko |
| Předmět: |
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| Zdroj: |
American Journal of Physiology: Regulatory, Integrative & Comparative Physiology; May2003, Vol. 53 Issue 5, pR1255, 5p, 2 Diagrams, 4 Graphs |
| Abstrakt: |
Ninety male Sprague-Dawley rats were exposed to 1:1-h light-dark (LD1:1) cycles for 50-90 days, and then they were released into constant darkness (DD). During LD1:1 cycles, behavioral rhythms were gradually disintegrated, and circadian rhythms of locomotor activity, drinking, and urine 6-sulfatoxymelatonin excretion were eventually abolished. After release into DD, 44 (49%) rats showed arrhythmic behavior for >10 days. Seven (8%) animals that remained arrhythmic for >50 days in DD were exposed to brief light pulses or 12:12-h light-dark cycles, and then they restored their circadian rhythms. These results indicate that the circadian clock was stopped, at least functionally, by LD1:1 cycles and was restarted by subsequent light stimulation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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