For efficient and accurate information processing in cerebral cortex, neural population dynamics must be spatially and temporally regulated with great precision. Medial prefrontal cortex (mPFC) of rodents has been shown important for various types of learning and memory, including fear memory. However, it has been challenging to understand the computational architecture in the mPFC, of which major problems are the complexity and heterogeneity of the prefrontal computation. We investigate this by chronic two-photon Ca2+ imaging from populations of neurons in mouse mPFC in vivo, which allows us to record activities simultaneously from large number of neurons at the single cell resolution, and investigate changes of neuronal responses over the learning process. We investigated the change in responses of mPFC neurons during Pavlovian fear conditioning (tone + aversive stimulus) and memory retrieval using a new device to perform them with a head fixed mouse. In the presentation, I will discuss how individual neurons and the neural population encode the fear memory.
