The Rhesus Monkey Hippocampus Critically Contributes to Scene Memory Retrieval, But Not New Learning


We know the hippocampus is important for memory, but many of the lesion studies in humans and non-human primates investigating the role of the hippocampus in memory have also affected other related structures. Studies in rodents can overcome this difficulty, but it is not possible to study many distinct memories in rodents. This makes it hard to identify the precise role of the hippocampus in encoding and recall of multiple episodic memories. We investigated how precise lesions to the hippocampus affect the recall of memories created 1-4 months before the lesion, and the creation of new episodic memories after the lesion. Lesions to the hippocampus affected recall of memories, no matter how old they were. This shows that the hippocampus is important for recalling episodic memories for a long time into the past. Perhaps surprisingly, the lesions did not affect the ability to create new memories. We need to investigate ways by which new episodic memories can be created without a functioning hippocampus.

Journal of Neuroscience