WebEx Details
Short description:
The medial entorhinal cortex (MEC) plays a critical role in mammalian spatial learning and potentially contributes to the impairment of spatial memory in the early stage of Alzheimer’s disease. Although the MEC neurons have been shown to encode various aspects of spatial and self-motion information during navigation, little is known about whether and how their activity dynamics implies the encoding of spatial memory during learning. We took advantage of the recent advance in in vivo two-photon microscopy combined with virtual reality to longitudinally track the calcium dynamics of hundreds of neurons in the MEC over multiple days, while mice learned to navigate a novel environment for water rewards. We found a significant variation in the behavioral performance of individual mice to learn the location of the water reward. The high learning performance strongly correlated with an increased number of active cells upon entering the novel environment, high intra- and inter-day consistency of neuronal activity, and an increased ability to decode position information based on the activity pattern of the neural population. The abundance of c-fos+ MEC neurons in the novel environment and the preliminary optogenetic experiments further suggest that the consistent neuronal activity of the MEC is important for the encoding of spatial memory during learning. Overall, our study demonstrates a close link between the neural dynamics of the MEC and spatial learning performance.