The platypus and short nosed echidna are monotremes, egg-laying mammals that have many characteristics of the reptilian predecessors of the mammals. Although originally thought to lack REM sleep, both species have aspects of this state, with the platypus actually having more REM sleep than any other mammal.
Video shows orca mother and calf at 4 weeks postpartum, at which point some sleep behavior has just begun to return in the mother. The neonate, circling and vocalizing, remains more active than the mother during this recording, as it does throughout development.
Informational piece about sleep research on marine mammals (cetaceans). Video produced by ScienCentral, supported by the National Science Foundation.
Video of untreated and of immunosuppressed narcoleptic dogs during food elicited cataplexy tests (FECTs) and the play behavior of the treated dogs.The first segment shows the administration of the FECT to three untreated narcoleptic littermate dogs, age 2.5 months. Dogs are labeled by shaved bands on their backs. Cataplexy is visible as a loss of muscle tone in the hind or fore limbs, drooping tail, sagging posture, wide stance, swaying, drooping eyelids, or interruption of eating caused by jaw hypotonia. The second segment shows the same test administered on the same day to the treated littermates of the dogs shown in the first segment. Little or no cataplexy is seen. Finally, the play segment, also filmed on the same day, shows that the lack of cataplexy in the treated animals is not accompanied by a behavioral depression. Play behavior is vigorous and normal.
see "Human sleep deprivation for 17 days: the Science Fair project of Randy Gardner" (right hand side of this page).
