In a new preprint published on bioRxiv, we show that behavioral flexibility in rats is supported by brief interactions between the prefrontal cortex and hippocampus that may facilitate memory reactivation.
As Greek philosopher Heraclitus said: “The only constant in life is change”. What is important is how well and how quickly one adapts to a change. In a new study, PhD student Hanna den Bakker studied the brain networks that are responsible behavioral flexibility in rats. Both the executive system in the prefrontal cortex and the long-term memory system in the hippocampus have been implied in the ability to adapt to changes in the environment. However, how these two brain regions interact and at what times they interact to support flexible behavior was not known.
Hanna, together with colleagues Marie Van Dijck and Jyh-Jang Sun, hypothesized that the relevant interaction occurs at the time of spontaneous reactivation of memory traces in the hippocampus (i.e., “replay”) that occur during reward consumption, rest and sleep. They used light to inhibit the activity in the prefrontal cortex immediately following putative replay events in the hippocampus. The results showed that prefrontal activity in this time window, but not at other times, is required for animals to successfully adapt to a rule change in a spatial memory task.
