Fig. 6. Significant effect of stress on total grid crosses (A), rearing (B), latency to move into the center grid-block (i.e., the six central grids) (C), and the ratio of the central/total grid crosses (D). Chronic stress decreased total grid crosses, rearing, and the ratio of central/total grid crosses, as well increase the latency (sec) to enter the central grid block. A, B, and D are based on frequency data. C depicts the effect of stress and lithium on the latency to move into the central grid block and is based on a 300-sec-maximum trial. Lithium treatment did not prevent the effects of stress on behavior.