RT Journal Article
SR Electronic
T1 Asymmetry of the temporal code for space by hippocampal place cells
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 060590
DO 10.1101/060590
A1 Bryan C. Souza
A1 Adriano B. L. Tort
YR 2016
UL http://biorxiv.org/content/early/2016/06/24/060590.abstract
AB Hippocampal place cells convey spatial information through spike frequency (“rate coding”) and spike timing relative to the theta phase (“temporal coding”). Whether rate and temporal coding are due to independent or related mechanisms has been the subject of wide debate. Here we show that the spike timing of place cells couples to theta phase before major increases in firing rate, anticipating the animal’s entrance into the classical, rate-based place field. In contrast, spikes rapidly decouple from theta as the animal leaves the place field and firing rate decreases. Therefore, temporal coding has strong asymmetry around the place field center. We further show that the dynamics of temporal coding along space evolves in three stages: phase coupling, phase precession and phase decoupling. These results suggest that place cells represent more future than past locations through their spike timing and that independent mechanisms govern rate and temporal coding.