Correlation between head direction cell activity and spatial behavior on a radial arm maze.

This study assessed the activity of head direction (HD) cells during performance of a spatial reference memory task on a radial arm maze. Rats were trained to select a maze arm located in a constant position in relation to a salient extramaze visual landmark. HD cell discharge properties remained relatively stable across task acquisition in most rats. Following acquisition, rotation of the landmark by 90 degrees or 180 degrees usually led to a corresponding shift in the maze arm selected and the HD cell's preferred firing direction. When the cell's preferred direction did not shift, rats usually selected the wrong arm. HD cell activity was not influenced by the rat's approach to the goal, reward consumption, or exit from the reward area. This demonstration of landmark control over behavior and the cell's preferred direction supports the hypothesis that HD cells contribute to an absolute representation of the environment that can be used to guide spatial behavior.