Vigilance states and body temperature during the circadian cycle in fed and fasted pigeons ( Columba livia)

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 1998-11, Vol.275 (5), p.R1690
• Main Authors: Rashotte, Michael E, Pastukhov, Iuri F, Poliakov, Eugene L, Henderson, Ross P
• Format: Article
• Language: English
• ISSN: 1522-1490

Fasting induces nocturnal hypothermia in pigeons. Slow-wave sleep (SWS) and paradoxical sleep (PS) are associated with reduced heat production in pigeons. The possibility that fasting-induced nocturnal hypothermia is related to increased SWS and PS was examined by comparing body temperature (T ) and vigilance states when pigeons were fed and fasted. The results showed that when T is decreasing near the beginning of the dark phase, the percentage of total recording time (%TRT) spent in SWS and PS was elevated in fasting due to increased frequency of episodes and increased duration of PS episodes. When T was low during the middle segment of the dark phase, SWS was elevated in fasting due to increased episode duration. However, fasting did not alter PS, which increased in %TRT across the segment due to increased episode frequency. When T was rising during the final hours of dark, SWS remained elevated in fasting and %TRT in SWS and PS was relatively high. SWS and PS may promote the fasting pigeon's entry into, and maintenance of, nocturnal hypothermia.