MONITORING AND EVALUATION OF CIRCADIAN LOCOMOTOR ACTIVITIES IN RODENTS

Locomotor behaviour is regarded as a fundamental index of general animal activity. Circadian rhythms (CRs) of locomotor activity are one of the most prominent biological rhythms which synchronize to the natural environmental light-dark cycle (LD). The present study aims to develop a reliable and precise setup for long-term recordings of the CRs in laboratory rodents (e.g. rats, hamsters, and mice). The recording setup consists of accessible running wheels (RW) in animal cages. Revolutions of RW were acquired through a circuit supported by either magnetic reed or infrared (photocell) switch sensors. Data acquisition and analysis were controlled through proper software. In a series of experiments, the CRs patterns were successfully recorded under LD, as well as constant darkness (DD) conditions. In summary, the recording setup enabled, with an acceptable precision, to record and analyses the animal's circadian locomotor activity patterns automatically without upsetting its behaviour pattern. Measurements and analysis of CRs of locomotor activities using this setup could be applied in various research issues such as chronobiological, neuroethological, physiological, and pharmacological studies.