Figure 5.

Atropine treatment produced variable effects on HD cell activity during performance in the dual chamber apparatus. A) Some cells were influenced by the visual cue card, and then shifted to an intermediate direction upon return to the cylinder (left); other cells were influenced by the cue card and then returned precisely to the original alignment upon return (center); other cells drifted or were otherwise unstable within the rectangle, resulting in broad tuning curves (right). B) Temporal dynamics of HD cell activity in the novel rectangle. Control HD cells (left) remained relatively stable across the cylinder (Cyl) and the first four min (R1–R4) of the novel rectangle. In contrast, the preferred direction of many cells in the atropine group (right) drifted during the first four min of the rectangle session, relative to the cylinder.