Recently, we discovered that the CA1 hippocampal layer is functionally heterogenous and differently engage in ongoing oscillations. Using in vivo recordings, we found that deep and superficial CA1 pyramidal cells participate differentially during sharp-wave ripples associated to memory consolidation (Valero et al Nat Neu 2015). Using unsupervised clustering of ripple events, we next disclosed a mechanism determining firing selectivity and its distorsion in the epileptic hippocampus (Valero et al. Neuron 2017). Our data support the idea of a strong regionalization of hippocampal function during basic processes underlying memory consolidation.