Fig. 1: Membrane voltage imaging of individual striatal neurons (SYNs) and cholinergic interneurons (ChIs) reveals prominent cellular voltage delta rhythmicity in mice during locomotion.

a, b Illustration of the (a) experimental setup and (b) surgically-placed imaging window. c An example ChI’s SomArchon fluorescence trace recorded at 833 Hz (left bottom, mean SomArchon fluorescence of the recorded neuron). Right, an example SomArchon fluorescence trace, with a zoom-in view (below) of the period indicated by the green box, and a further zoom-in (right). d Top, the inter-spike interval (ISI) distribution of the example ChI shown in c. Bottom, the ISI return map. The delta frequency range is illustrated with orange shading. e Same as c, but for an example SYN. f Same as d, but for the example SYN shown in e. Scale bars are 15 μm. g The population ISI distribution of delta-rhythmic neurons (n = 31). Arrow indicates the delta time-scale ISI distribution peak. h The ISI return map of all delta-rhythmic neurons (n = 31). i, j The population ISI distribution (i) and ISI return map (j) of non-delta neurons (n = 21). k, l Pie chart illustration of the fraction of (k) ChI neurons and (l) SYN neurons identified as delta-rhythmic or non-delta rhythmic. m Population firing rate for ChIs and SYNs. There was no difference between ChIs and SYNs (independent t-test, p = 0.16, n = 52, with 27 ChIs and 25 SYNs, df = 50). n Population firing rate for delta-rhythmic (D) and non-delta (ND) neurons (independent t-test, p = 0.007, n = 52, with 31 delta-rhythmic neurons and 21 non-delta neurons, df = 50). o Mean firing rate quantification for delta-rhythmic and non-delta ChIs (independent t-test, p = 0.26, n = 27, df = 25). p Same as o, but for SYNs (independent t-test, p = 0.04, n = 25, df = 23). Quantifications in m–p are visualized as violin plots with the outer shape representing the data kernel density and a box-and-whisker plot (box: interquartile range, whiskers: 1.5x interquartile range, white line: mean). All statistical tests are two-sided. Source data are provided as a Source Data file.