About the Database
This database contains what are known as sleep quotas for
178 separate references, on 127 different species (as of June 29, 2007), in 46 families, across 17 orders,
with additional sleep data on other species being added to the database as they become available. Sleep quotas are essentially time spent in each of the two major sleep states (REM and NREM) per day. There are several lines of evidence that point to the fundamental importance of sleep quotas for an analysis of sleep state function.
- Duration of REM and NREM sleep states appear to be regulated by separate sets of genes in mammals. For example, mouse strains “C57BL” and “C57BR” are associated with increased REM and short slow-wave sleep (SWS) episodes while BALB/c is associated with short REM and long NREM episodes.
- Deprivation of or restriction in the amount of REM or NREM sleep leads to a sleep debt, as manifested by sleep rebound effects after a deprivation period. The rebound is proportional to the amount of sleep lost during the deprivation period. Thus, the phenomenon of an incurred sleep debt implies that mammals need a certain amount of sleep in order to function properly.
- Sleep times for a given bout of a particular sleep state vary considerably across mammalian species from a low of about 15 minutes to a high of about 2 hours.
- Sustained reductions in sleep times for either of the two major sleep states results in significant and increasing impairment in fundamental physiologic functions and eventual death - at least in some species.
- Sleep quotas are reliably associated with physiologically significant measures of mammalian biology.
- Major human disorders of sleep manifest as changes in sleep amounts with either too little (insomnia) or too much (excessive daytime sleepiness) sleep. Changes in amount of sleep predict clinically significant physiologic and mental health dysfunction.
Thus, sleep quotas appear to be reliable and meaningful indexes of sleep biology and clinically significant sleep disorders in humans. In addition to these data on sleep durations, we also include ratings on the quality of the data. You will find other data on the physiologic and life history characterstics of the species represented in the dataset via the links listed under "Resources".