This study examined how incorporation of synthetic hippocampal signals is constrained by pre-existing circuit dynamics. For this study, they optogenetically stimulated small groups of CA1 neurons as mice traversed a chosen segment of a linear track, which mimicked the emergence of place fields. Mice were trained to run laps on a linear track to retrieve water reward at each end. Before implantation, water access was restricted and was only available as reward on a linear track. The dataset includes behavioral and electrophysiology data. The data indicates that optogenetic depolarization of CA1 pyramidal neurons induces place fields to emerge in locations with weak pre-existing drive.