SUMMARY Like human narcoleptics, narcoleptic dogs display cataplexy, fragmented sleep and excessive daytime sleepiness. Cataplexy in dogs can easily be quantified using a simple behavioural bioassay, the Food Elicited Cataplexy Test. In contrast, daytime sleepiness and fragmented sleep are more difficult to measure, as long-term, labour-intensive polygraphic recordings in surgically-implanted animals are needed. In the current study, 24-h rest/activity patterns in genetically narcoleptic, asymptomatic heterozygous and control Dobermans were compared using small sized ambulatory activity monitoring devices under 12-h light/dark conditions. Control and heterozygous dogs were found to be more active during the light period than during the dark period, thus demonstrating a clear 24-h rest/activity cycle. In contrast, narcoleptic dogs were relatively inactive during the light period and did not show a clear rest/activity pattern, a result similar to that of human narcoleptics. Considering the fact that narcoleptic dogs show shorter sleep latency and sleep significantly more during the daytime than control dogs, the decrease in activity in narcoleptic dogs during the daytime is most likely a reflection of increased daytime napping in these animals. Ambulatory activity monitoring may be a useful non-invasive method for future pharmacological and developmental studies in the narcoleptic canine model.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.