Fig. 4: A hyperpolarization during odor onset resets intracellular theta.
From: Voltage imaging reveals hippocampal inhibitory dynamics shaping pyramidal memory-encoding sequences
a, Example trials from three PV cells (from three different mice) with odor-triggered hyperpolarization traces. Average FOV (left). ΔF/F, detected spikes and locomotion during four DNMS trials, displayed as before (middle). Expanded traces within box (right). b, Trial-average theta-bandpassed ΔF/F (gray) and odor A (yellow) and odor B (green) average ΔF/F across all corresponding trials, for the three cells shown in a. c,d, Same as a,b for three example SST cells (from three different mice). Licks shown for one trained session. e, Percentage of trials with a significant hyperpolarization per cell. Lines indicate median values (P = 0.9; WT). Insets show average odor-triggered ΔF/F over trials with significant and nonsignificant hyperpolarization. f, Distribution of mean amplitude of ΔF/F hyperpolarization per cell (z-score-scaled over baseline of 0.5 s before odor onset; P = 0.98; WT). g–i, Distribution of hyperpolarization onset time (g), time of minimum ΔF/F (h) and hyperpolarization duration (i). Distributions truncated at 400 ms for clarity. P = 0.06, 2.4 × 10−4, 6.3 × 10−4; two-sided WT; FDR. j, Amplitude of maximum depolarized versus hyperpolarized ΔF/F during odor presentation. Lines show least square fit for each cell type. P = 0.004, 0.901 (PV, SST); F-test. One outlier removed for plotting clarity. k, Trial-average ΔF/F (top) and theta-bandpassed ΔF/F (bottom) for PV and SST cells. Insets show zoomed in segments around the first odor. l, Variance of theta phases across all trials. m,n, Average ΔF/F power spectral density for PV (m) and SST cells (n) across trials (top). Mean ± s.e. ΔF/F theta amplitude (bottom). o, Mean ± s.e. hyperpolarization amplitude across sessions and naive versus trained session averages (right) for PV and SST cells (n = 26 versus 57 PV recordings and 33 versus 36 SST). P = 0.0068, 1 (PV, SST); two-sided WT. p, Same for rate of hyperpolarization occurrence (n = 31 versus 76 PV recordings and 36 versus 51 SST). P = 0.022, 0.0005 (PV, SST), two-sided WT. ρS, Spearman correlation with imaging sessions, P = 0.0027, 0.0019 (PV, SST), random permutation test.
