Preexisting Hippocampal Network Dynamics Constrain Optogenetically Induced Place Fields

This study examined how incorporation of synthetic hippocampal signals is constrained by pre-existing circuit dynamics. The postulated ability for hippocampal circuits to imprint a random, novel pattern was tested in CaMKIIα-Cre::Ai32 mice (N = 5) in which channelrhodopsin2 was expressed in excitatory pyramidal neurons. For the study, μLED silicon probes were implanted in dorsal CA1 to record neural activity during sleep and behavior as mice ran on a linear track for water reward. Prior to any stimulation, neurons were recorded for at least one hour while mice stayed in their homecage (REST1), followed by running laps on a linear track (RUN1), another 1–4 hour long recording in the homecage (REST2), and then a final recording session on the track (RUN2) to test long-term place field stability. This dataset includes electrophysiology and behavioral data.