Fig. 3: Single units change phase preference when active in different assemblies.
a Raster plot and phase preference of two example assemblies, assembly A and assembly B, with a shared unit (unit 2). Unit 2 changes phase preference when active in the two different assembly configurations, Kruskal–Wallis two-sided nonparametric test for angular data, p value reported in figure with no multiple-comparison adjustments (see Methods); b Fraction of units that change their phase preference when active in different assemblies. Boxplots mark the median (red), the mean weighted by the number of tested assemblies per session (cyan), min and max point (whiskers), and the 25th and 75th percentiles (bottom and top edges of the box) computed across animals after Benjamini–Hochberg multiple-comparison correction (\(\alpha=0.05\)), data points correspond to distinct recording sessions (four sessions of six rats, sessions where no units met the inclusion criteria were excluded, n = 15 and 21 for first and second bar, respectively); generalized linear mixed-effects model with logit link function: F(1,231) = 12.54, p = 4.8 × 10-4. * marks significance; c Mean and SE (shaded area) activity along the maze of the two assemblies displayed in (a) (top) and their composing units during different trial types (bottom). The trial typologies displayed are: left (pink) and right (red) choice trials, and left (blue) and right (black) guided trials. The assembly and unit activity are plotted along the linearized path. Vertical dashed lines mark different task segments, along the path from C to G, as indicated in the maze scheme for the left choice trial. Assembly temporal resolution, composing units, and lag of activation of each unit with respect to the activation of the first assembly-unit are indicated in the figure title. Unit 2 takes part in both assemblies A and B, joining unit 1 and 3, respectively (the checkerboard covers the activity of units not part of the assembly). When firing in the two assemblies, the unit fires preferentially at two different firing phases (a) to encode different task-related information (left vs. right choice trials). See also Supplementary Fig. 6 for other examples of assembly-dependent phase modulation of CA1 units. Source data are provided as a Source Data file.
