| First Author | Taxidis J | Year | 2020 |
| Journal | Neuron | Volume | 108 |
| Issue | 5 | Pages | 984-998.e9 |
| PubMed ID | 32949502 | Mgi Jnum | J:300527 |
| Mgi Id | MGI:6503489 | Doi | 10.1016/j.neuron.2020.08.028 |
| Citation | Taxidis J, et al. (2020) Differential Emergence and Stability of Sensory and Temporal Representations in Context-Specific Hippocampal Sequences. Neuron 108(5):984-998.e9 |
| abstractText | Hippocampal spiking sequences encode external stimuli and spatiotemporal intervals, linking sequential experiences in memory, but the dynamics controlling the emergence and stability of such diverse representations remain unclear. Using two-photon calcium imaging in CA1 while mice performed an olfactory working-memory task, we recorded stimulus-specific sequences of "odor-cells" encoding olfactory stimuli followed by "time-cells" encoding time points in the ensuing delay. Odor-cells were reliably activated and retained stable fields during changes in trial structure and across days. Time-cells exhibited sparse and dynamic fields that remapped in both cases. During task training, but not in untrained task exposure, time-cell ensembles increased in size, whereas odor-cell numbers remained stable. Over days, sequences drifted to new populations with cell activity progressively converging to a field and then diverging from it. Therefore, CA1 employs distinct regimes to encode external cues versus their variable temporal relationships, which may be necessary to construct maps of sequential experiences. |
