RT Journal Article
SR Electronic
T1 The hippocampus as a sorter and reverberatory integrator of sensory inputs
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.01.10.475731
DO 10.1101/2022.01.10.475731
A1 Masanori Nomoto
A1 Emi Murayama
A1 Shuntaro Ohno
A1 Reiko Okubo-Suzuki
A1 Shin-ichi Muramatsu
A1 Kaoru Inokuchi
YR 2022
UL http://biorxiv.org/content/early/2022/01/11/2022.01.10.475731.abstract
AB In entorhinal-hippocampal networks, the trisynaptic pathway, including the CA3 recurrent circuit, processes episodes of context and space1-3. Recurrent connectivity can generate reverberatory activity4-6, an intrinsic activity pattern of neurons that occurs after sensory inputs have ceased. However, the role of reverberatory activity in memory encoding remains incompletely understood. Here we demonstrate that in mice, synchrony between conditioned stimulus (CS) and unconditioned stimulus (US)-responsible cells occurs during the reverberatory phase, lasting for approximately 15 s, but not during CS and US inputs, in the CA1 and the reverberation is crucial for the linking of CS and US in the encoding of delay-type cued-fear memory. Retrieval-responsive cells developed primarily during the reverberatory phase. Mutant mice lacking N-methyl-D-aspartate receptors (NRs) in CA3 showed a cued-fear memory impairment and a decrease in synchronized reverberatory activities between CS- and US-responsive CA1 cells. Optogenetic CA3 silencing at the reverberatory phase during learning impaired cued-fear memory. Our findings suggest that reverberation recruits future retrieval-responsive cells via synchrony between CS- and US-responsive cells. The hippocampus uses reverberatory activity to link CS and US inputs, and avoid crosstalk during sensory inputs.Competing Interest StatementThe authors have declared no competing interest.