Figure 5.

Immature DCX⁺ neurons are not important for recall of a previously learned task but are important for learning new hippocampal-dependent tasks. A, Experimental design used to assess recall of the already learned task after DT treatment, as well as learning of a new task where the cues and entry point have been altered. B, There was no difference in the number of shocks delivered during the initial learning period in the active place avoidance task (F_(1,18) = 0.02, p = 0.88). C, When retested after DCX⁺ cell ablation, DCX^DTR mice performed equally as well as controls (F_(1,18) = 0.16, p = 0.70). D, Changing the distal visual cues and shock/entry zone positions precipitated a deficit in DCX-ablated animals, which showed impaired acquisition of this new task as evidenced by a significant increase in the number of shocks received by this group on day 3 of the new training protocol (F_(1,18) = 4.51, p < 0.05). S indicates experimental session (i.e., S1, Session 1). *p < 0.05, significance between genotypes for individual trial days (Bonferroni post hoc test). WT: n = 11; DCX^DTR: n = 9.