The place preference task: a new tool for studying the relation between behavior and place cell activity in rats.
This study describes a task that combines random searching with goal directed navigation. The testing was conducted on a circular elevated open field (80 cm in diameter), with an unmarked target area (20 cm in diameter) in the center of 1 of the 4 quadrants. Whenever the rat entered the target area, the computerized tracking system released a pellet to a random point on the open field. Rats were able to learn the task under light and in total darkness, and on a stable or a rotating arena. Visual information was important in light, but idiothetic information became crucial in darkness. Learning of a new position was quicker under light than in total darkness on a rotating arena. The place preference task should make it possible to study place cells (PCs) when the rats use an allothetic (room frame) or idiothetic (arena frame) representation of space and to compare the behavioral response with the PCs' activity.