Abstract
Hippocampus and prefrontal cortex individually are both known to be important in storing and retrieving memories to guide behaviors. Studies showing the functional overlap, anatomical connection and coordination of neuronal network activity patterns of these two regions indicate that hippocampus and prefrontal cortex communicate with each other to support learning, working memory formation and memory guided decision-making. In this research project, we aim to test the hypothesis that perturbing ipsilateral interactions between dorsal hippocampus (dHPC) and media prefrontal cortex (mPFC) will impair the rats’ abilities for learning and retrieving spatial memories. A chemogenetic approach, DREADDs (Designer Receptors Exclusively Activated by Designer Drugs), was used to inactivate the target brain regions in rats learning a W-track continuous spatial alternation task. This hippocampal-dependent task is comprised of two different components that depend on different types of memory. In order to test whether or not this task is also mPFC dependent, and whether or not ipsilateral interactions between dHPC and mPFC are important for this task, we implemented a multi-day spatial alternation task paradigm with separable phases of learning and retrieval after task acquisition. We found that the learning process of the outbound component of this task, but not the inbound component, was significantly impaired if the interactions between dHPC and mPFC were impaired, or mPFC was inactivated bilaterally.