Wang and colleagues find that weakening hippocampal theta in a familiar environment reduces the performance of rats in a spatial memory task, decreases the number of theta sequences and degrades internally generated hippocampal episode cell firing, while leaving place cell firing intact. The same weakening of theta also prevents the formation of a precise spatial representation in a novel environment unless proximal cues are present. Together these results suggest that the mechanisms underlying internally generated hippocampal sequences of activity are crucial for episodic memory.
- Yingxue Wang
- Sandro Romani
- Eva Pastalkova
