Fig. 3: Reactivation of SD-encoding ventral hippocampal neurons by ventral hippocampal SWRs.
From: Hippocampal sharp wave ripples underlie stress susceptibility in male mice
a (Left) Multiunit spikes were recorded from ventral hippocampal CA1 neurons. b Images of the recording processes during SD, including during no interaction (left) and attacking or mounting (right). c (Top) Changes in instantaneous the firing rates (bin = 1 and 10 min in the rest and SD periods, respectively) of two representative vHC neurons showing significant increases (left, SD excited) and decreases (right, SD inhibited) in their firing rates during SD stress. (Bottom) The SD periods are magnified from the top panels (bin = 1 s). The magenta bars indicate periods of attacking or mounting of the SD mice. The yellow regions indicate periods that were removed from the analysis due to severe noise. d Scatterplot comparing neuronal firing rates between the prestress (2 h) and SD periods (n = 40 cells), shown in different colors depending on their relation to SD. Each dot represents a neuron. e Changes in the average firing rates of all SD-excited (n = 15) and SD-inhibited (n = 20) putative pyramidal neurons of each cell type. * and $ represent significant increases and decreases in rates, respectively, compared with the 30-min prestress period (SD-excited: versus SD, *P = 2.4 × 10−4; versus 0–30-min post, *P = 4.8 × 10−4; versus 30–120-min post, *P = 2.4 × 10−4; SD-inhibited: versus SD, $P = 3.5 × 10−4, two-sided Wilcoxon signed rank test followed by Bonferroni correction). The data are the mean ± SEM. f Comparison of ventral hippocampal SWR-triggered spike rate changes between the prestress and poststress periods for representative SD-excited (left) and SD-inhibited (right) ventral hippocampal neurons. In each graph, the z-scored firing rates of SWRs are shown. g Comparison of the firing rates of ventral hippocampal SWRs between the prestress and poststress periods. Each dot represents a cell (n = 40 cells). h Relationship between the ratio of the firing rate in the SD period to that in the prestress period and the ratio of the SWR-associated firing rate in the poststress period to that in the prestress period. Each dot represents a neuron (n = 15, 5, and 20 neurons). i Distributions of the same data corresponding to H. An asterisk indicates a significant difference (Z = 2.78, *P = 0.0054, two-sided Mann–Whitney U test) in the SWR-associated firing rate between the prestress and poststress periods.
