Academic Journal
Sleep and Thermoregulation in Birds: Cold Exposure Reduces Brain Temperature but Has Little Influence on Sleep Time and Sleep Architecture in Jackdaws (Coloeus monedula).
| Title: | Sleep and Thermoregulation in Birds: Cold Exposure Reduces Brain Temperature but Has Little Influence on Sleep Time and Sleep Architecture in Jackdaws (Coloeus monedula). |
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| Authors: | van Hasselt, Sjoerd J., Coscia, Massimiliano, Allocca, Giancarlo, Vyssotski, Alexei L., Meerlo, Peter |
| Source: | Biology (2079-7737); Apr2024, Vol. 13 Issue 4, p229, 14p |
| Abstract: | Simple Summary: Birds have an electrophysiological sleep state that resembles rapid-eye-movement (REM) sleep in mammals. Whether the regulation and function of this REM sleep state in birds is similar to that in mammals is unclear. In the current experiment, we studied sleep regulation in jackdaws (Coloeus monedula) by exposing the birds to low ambient temperature, a procedure that selectively suppresses REM sleep in mammals. Jackdaws were equipped with electrodes to record brain activity and neck muscle activity and a sensor to record brain temperature. Exposure to a low ambient temperature of 4 °C during the nighttime sleep phase caused a significant drop in brain temperature of 1.4 °C, compared to the baseline night at 21 °C. However, cold exposure did not affect the amount of NREM sleep and REM sleep. This indicates that REM sleep in jackdaws is protected against the influence of low temperature. Hence, the well-established relationship between thermoregulation and REM sleep regulation that exists in mammals may not be present in birds. Birds have an electrophysiological sleep state that resembles mammalian rapid-eye-movement (REM) sleep. However, whether its regulation and function are similar is unclear. In the current experiment, we studied REM sleep regulation in jackdaws (Coloeus monedula) by exposing the birds to low ambient temperature, a procedure that selectively suppresses REM sleep in mammals. Eight jackdaws were equipped with electrodes to record brain activity and neck muscle activity and a thermistor to record cortical brain temperature. Recordings covered a three-day period starting with a 24 h baseline day at an ambient temperature of 21 °C, followed by a 12 h cold night at 4 °C, after which the ambient temperature was restored to 21 °C for the remaining recovery period. Cold exposure at night caused a significant drop in brain temperature of 1.4 °C compared to the baseline night. However, throughout the cold night, jackdaws expressed NREM sleep and REM sleep levels that were not significantly different from the baseline. Also, EEG spectral power during NREM sleep was unaffected by cold exposure. Thus, while cold exposure had a clear effect on brain temperature in jackdaws, it did not have the same REM sleep suppressing effect reported for mammals. These findings suggest that the REM-sleep-like state in birds, unlike REM sleep in mammals, is protected against the influence of low temperature. [ABSTRACT FROM AUTHOR] |
| Subject Terms: | NON-REM sleep, RAPID eye movement sleep, SLEEP duration, SLEEP, BODY temperature regulation, LOW temperatures, THERMISTORS, NECK muscles, AVIAN anatomy |
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| ISSN: | 20797737 |
| DOI: | 10.3390/biology13040229 |
| Database: | Complementary Index |
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