Sparse-to-dense coding transformation between hippocampal areas CA3 and CA1 - Shir R. Maimon; Tamir Eliav; Johnatan Aljadeff; Aviya Shalev; Yishai Gronich; Nikita M. Finger; Keegan E. Eveland; Cynthia F. Moss; Liora Las; Nachum Ulanovsky (Nature, 2026)