Water as entrainer of circadian running activity in rat.

The present work is designed to study the competing influence of periodic presentation of water on the running activity of the rat having free access to the cues fulfilling his instinctual drives, namely, food, water, male rat and primed female. Seven male, adult albino rats were used for the study. The 24 hour activity shift patterns of the incentive drives for food, water, male rat and primed female were recorded with the help of a maze-cum-activity cage with an automatic recording system fabricated in the laboratory, and under different schedules of periodic presentation of water. It was observed that the activity pattern shifted towards the drinking period with burst of running preceding water presentations. The findings of this study show that periodic water presentation is as significant as periodic food presentation in entraining the circadian running activity of the rat.