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Quantification of ECoG stages of sleep in the bottlenose dolphin


Single-hemisphere low-wave sleep was shown to be the dominant form of natural sleep according to quantitative analysis of duration of ECoG sleep phases. Combined variants of bilateral and unilateral ECoG synchronization total 33.4% of the 24-h cycle, of which unilateral slow-wave sleep accounts for 28.8%. Each of the bottlenose dolphin's two hemispheres remains in a state of slow-wave ECoG for an average of 19% of the cycle. The highest percentage duration of sleep occurred during the afternoon and nighttime. Overall duration of ECoG synchronization may differ in the two hemispheres but evens out in the dolphin over a number of 24-h cycles. Spells of single-hemisphere sleep tend to alternate between the two different hemispheres.

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Additional information

A. N. Severtsov Institute of Evolutionary Morphology and Animal Ecology. Translated from Neirofiziologiya, Vol. 20, No. 4, pp. 532–538, July–August, 1988.

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Mukhametov, L.M., Oleksenko, A.I. & Polyakova, I.G. Quantification of ECoG stages of sleep in the bottlenose dolphin. Neurophysiology 20, 398–403 (1988).

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  • Quantitative Analysis
  • Dominant Form
  • Bottlenose Dolphin
  • Combine Variant
  • Sleep Phase