Subiculum as a generator of sharp wave-ripples in the rodent hippocampus

• DOI: 10.1016/j.celrep.2021.109021
• Publication Date: 2021-04-21T04:30:41Z
• Authors: Barbara Imbrosci; Noam Nitzan; Sam McKenzie; José R. Donoso; Aarti Swaminathan; Claudia Böhm; Nikolaus Maier; Dietmar Schmitz
• Keywords: Male; Patch-Clamp Techniques; physiology [Synaptic Potentials]; hippocampus; QH301-705.5; CA3; sharp wave-ripples; Synaptic Transmission; CA1; Article; anatomy & histology [Entorhinal Cortex]; Mice; 03 medical and health sciences; Animals; Entorhinal Cortex; Rats, Long-Evans; ddc:610; Biology (General); CA1 Region, Hippocampal; physiology [Brain Waves]; Memory Consolidation; Neurons; 0303 health sciences; physiology [CA1 Region, Hippocampal]; entorhinal cortex; anatomy & histology [CA1 Region, Hippocampal]; Microtomy; Synaptic Potentials; physiology [Neurons]; Brain Waves; CA3 Region, Hippocampal; physiology [Memory Consolidation]; Electrodes, Implanted; Rats; Mice, Inbred C57BL; physiology [CA3 Region, Hippocampal]; physiology [Synaptic Transmission]; subiculum; cytology [Neurons]; oscillations; Integrative Biomedicine [Topic 3]; anatomy & histology [CA3 Region, Hippocampal]; Function and Dysfunction of the Nervous System; physiology [Entorhinal Cortex]

Sharp wave-ripples (SWRs) represent synchronous discharges of hippocampal neurons and are believed to play a major role in memory consolidation. A large body of evidence suggests that SWRs are exclusively generated in the CA3-CA2 network. In contrast, here, we provide several lines of evidence showing that the subiculum can function as a secondary SWRs generator. SWRs with subicular origin propagate forward into the entorhinal cortex as well as backward into the hippocampus proper. Our findings suggest that the output structures of the hippocampus are not only passively facilitating the transfer of SWRs to the cortex, but they also can actively contribute to the genesis of SWRs. We hypothesize that SWRs with a subicular origin may be important for the consolidation of information conveyed to the hippocampus via the temporoammonic pathway.