Sleep patterns of five rodent species

Abstract Electrographic and behavioral observations were made on five rodent species under controlled conditions. These were: Mus musculus, Rattus norvegicus, Mesocricetus auratus, Citellus tridecemlineatus and Chinchilla laniger . Normative values for sleep characteristics of the five species were derived from 48 hr recording periods. Analysis of sleep pattern characteristics showed: (1) well defined stages of slow wave sleep and paradoxical sleep in all animals; (2) sleep occupied from 52–60 per cent of each day for the different species; (3) different species differed in percentage of paradoxical sleep ranging from 10 per cent for the mouse to 24 per cent for hamsters and ground squirrels; (4) hibernators slept in significantly longer periods, had higher percentages of paradoxical sleep and slightly higher percentages of total sleep time. Hibernators also seemed to sleep more deeply than non-hibernators.