Figure 1.

Learning increases cell survival in the hippocampus. (A) BrdU was injected 1 wk before the start of training. Massed subjects were trained with four consecutive blocks of four trials in 1 d. Spaced subjects were trained with one block of four trials for four consecutive days. Animals from both groups (plus a naïve group with no training) were perfused 11 d after BrdU injection. (B) Mean escape latency for massed (○) and spaced (●) animals across 16 training trials. Animals trained with spaced trials were able to navigate to the platform in less time than animals trained with massed trials. (C) The number of BrdU cells that were observed 1 d after the end of spaced training is shown. Animals that were designated as good learners possessed more new cells in their dentate gyrus than did the poor learners and the naïve controls. (*) P < 0.05.