Bispectral Index Monitoring of Unihemispheric Effects in Dolphins
NAVAL MEDICAL CENTER SAN DIEGO CA
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When dolphins sleep, their electroencephalographic activity may change in only one cerebral hemisphere i.e., the left and right brain hemispheres can take turns sleeping. We demonstrate that the bispectral index BIS monitor can detect interhemispheric asymmetry in the dolphin species Tursiops truncatus. Using two BIS sensors place simultaneously over each side of the dolphins head, we often, but not always, found significant differences between the two BIS values e.g., left side 60 and right side 90 in non-medicated animals and in animals given propofol, atropine, andor diazepam. Observations were each made over a period of approximately 3 h on dolphins resting out of the water. Unihemispheric effects may be inducible pharmacologically in dolphins. The dolphin, with its human-sized brain, may provide an animal model for study of unihemispheric effects in humans.
- Medicine and Medical Research