The effect of age and sex on animal activities of daily living measured using an automated behavioural classification system over 23 hours The effect of age and sex on animal activities of daily living measured using an automated behavioural classification system over 23 hours
Trang Tran, John Mach, Gizem Gemikonakli and Sarah Hilmer
Lab of Ageing and Pharmacology, Kolling Institute of Medical Research Clinical Pharmacology and Ageing, Royal North Shore Hospital, Sydney, Australia Northern Clinical School, University of Sydney, Sydney, New South Wales, Australia
Activities of daily living (ADL) comprise basic self-care actions performed by individuals on a daily basis, which have been reported to have some age- and sex-specific differences. Animals are a common tool to investigate pharmacological and toxicological effects. The association between age and sex on general activities in animals have not been fully understood. Using a mouse model, we aim to investigate how both factors affect normal behaviours over a 23-hour time frame. Young and old C57BL/6 mice, 3 months and 22 months respectively, of two sexes have been assessed using an automated behaviour recording machine - the Laboratory Animal Behaviour Observation, Registration, and Analysis system (LABORAS) for 23 hours. Mice are individually house-caged and recorded for ADL including travelled distance and the duration of locomotion, immobility, rearing, grooming, eating and drinking. Preliminary results (n=2-3 for each sex and age) show that compared to old mice, the young animals had a significantly higher travelled distance and higher durations of drinking and locomotion over 23 hours, especially within the first 5 hours recording. Compared to young mice (7627±711 seconds), the grooming period of old mice was significantly longer (13682±1725 seconds). Regarding climbing, compared to the males (2002±648 seconds), female mice, regardless of age, spent more time climbing (7385±1782 seconds, p<0.05). No difference was observed with the duration of rearing and eating. The assessment will be continued for the rest of the cohort and different polypharmacy (concurrent use of ≥ 5 medications) regimens with increasing Drug Burden Index (DBI: cumulative exposure to anticholinergic and sedative drugs) will also be administered to investigate the effect of polypharmacy, DBI along with sex and age on animal behaviours. Our preliminary results suggest some differences in ADL, in particular, distance of travelling drinking, climbing and grooming in young, old and female and male over 23 hours.