Team effort by Ava Kiai, @talking-bat.bsky.social , Francisco García-Rosales and me :)

Our results indicate distinct contributions of the two hippocampal poles in spatial working memory and in communicating relevant spatial information to the prefrontal cortex.

Interestingly, prefrontal representations of the animal’s goal location during encoding was disrupted only when the ventral HPC was inactivated. Inactivation of the dorsal HPC had no effect on these spatial goal codes.

Then, we looked at prefrontal activity when either dorsal or ventral HPC were inactivated. We found that while neurons in the prefrontal cortex still represented the animal’s position in the maze, spatial codes were altered compared to trials with a functioning HPC.

However, the ventral HPC is only necessary in the encoding phase. Neither ventral nor dorsal HPC were needed to maintain the location in memory for a few seconds.

First, we found that the dorsal and the ventral HPC play distinct roles in supporting spatial working memory: the dorsal HPC is necessary during two critical phases of the task, namely during encoding a spatial location and while retrieving this information.