Topic: engram allocation

Memories are thought to be encoded in the brain via synaptic strengthening among memory engram cells. Still, it has not been possible to observe if learning potentiates synaptic connections and simultaneously show that these changes are causally related to memory expression (i.e., they occur in engram neurons). We used a novel engram allocation-based approach to observe synaptic changes in engram neurons upon learning in-vivo. Using optogenetics, we assigned selected Medial Entorhinal Cortex (MEC) neurons to a context fear memory. This takes advantage of the fact that neurons with more excitab