A1-A3, Examples of spatial units before, during, and after muscimol infusion. Spatial properties of single units decreased when ATN was inactivated. A3, Relative inactivity after 100-120 min, and the cell was not recorded the next day. B, Spatial alternation dropped to chance levels when the ATN were temporarily inactivated with muscimol, compared with the same animals before infusion. When saline was infused in place of muscimol, no deficit was present. C1-C3, Further examples of spatial units before and after ATN inactivation. C1, Disruption of place field shortly after muscimol infusion with some head directionality remaining, which was later disrupted. C3, No firing was detected after muscimol infusion. **p < 0.01 (ANOVA with Tukey post hoc).