Preadolescent development is characterized by a reorganization of connectivity within and between brain regions that coincides with the emergence of more complex behaviors. The hippocampus is one such region that undergoes extensive preadolescent remodeling and as this process continues, spatial memory functions emerge. The current work investigated whether preadolescent spatial memories persist beyond 24 h and stabilize into the postadolescent period as remote memories supported by cortical networks in the anterior cingulate cortex (ACC). Male Long Evans rats were trained on the Morris water maze at different time frames from postnatal day (P) 18–26 and compared to P50 rats. Testing occurred at either a recent (24 h) or remote (3 weeks) timepoint. Spatial learning was evident in all age groups (P18, P20, P22, P24 and P50) across the 3 training days but only the P22 and P24 groups showed spatial learning that matched the P50 group. In light of this, the only group to show intact remote (3 week) memory was the P50 group. Spaced training in the P18 group did not improve retention at the recent or remote testing intervals. The P18 and P50 groups tested at 24 h showed more CA1 hippocampal c-Fos labeling than groups tested at 3 weeks. The P50 group tested at 3 weeks showed elevated c-Fos labeling in the anterior cingulate (ACC) compared to the P18 group tested at 3 weeks and the P50 group tested at 24 h. Spaced training in the P18 group was associated with elevated c-Fos labeling in the ACC at the 3-week test. Groups trained at P20, 22, and 24 showed more c-Fos labelling in the ACC than in the CA1. Results suggest that while spatial information processing emerges around P18/P20, remote spatial retention and the neural substrates that support retention are not in place until after P26 in rats.

前期发育的特征是大脑区域内部和之间的连通性重新组织，这与更复杂的行为的出现相吻合。海马就是这样一个区域，该区域经历了青春期前的大量重塑，随着这一过程的继续，出现了空间记忆功能。当前的工作调查青春期前的空间记忆是否持续超过24小时并稳定到青春期后，这是由前扣带回皮层（ACC）中的皮质网络支持的远程记忆。在产后第18-26天的不同时间对雄性Long Evans大鼠进行Morris水迷宫训练，并与P50大鼠进行比较。测试在最近（24小时）或远程（3周）时间点进行。在所有年龄段（P18，P20，P22，P24和P50）在3个训练日内进行，但只有P22和P24组显示出与P50组匹配的空间学习。有鉴于此，唯一能显示完整的远程（3周）记忆的组就是P50组。P18组中的间隔训练在近期或远程测试时间间隔均未改善保持力。在24小时测试的P18和P50组显示比在3周测试的组更多的CA1海马c-Fos标记。与第3周测试的P18组和第24小时测试的P50组相比，第3周测试的P50组显示前扣带回（ACC）的c-Fos标记升高。在3周的测试中，P18组的间隔训练与ACC中c-Fos标记升高有关。在P20、22和24训练的小组在ACC中的c-Fos标记比在CA1中的标记多。