Although the contribution of the hippocampus to episodic memory is well-established, much remains to be known about the network mechanisms underlying memory retrieval at this level and the specific involvement of each hippocampal subfield in this process. I will present recent data based on activity-dependent gene mapping, optogenetics and behavioral techniques showing that dissociating CA1’s from CA3‘s contribution and the contribution of their proximal from that of their distal parts, are essential for a better understanding of spatial and non-spatial information processing in the medial temporal lobe for recent (few min) to very remote (1 year-old) memories (Nakamura et al, J. Neurosc., 2013; Lux et al, Elife, 2017; Beer and Vavra, Plos Biology, 2018).