Fig. 4

Depletion of microglial cells is sufficient to rescue the learning and memory impairments of LH mice. Male mice were fed with the AIN-76A diet (control diet) (b–d) or AIN-76A diet supplemented with PLX5622 (e–g) for 3 days before the induction of the learned helplessness paradigm and were maintained on the diet for the duration of the experiment. Three days after initiating the diet, mice were subjected or not (NS) to the learned helplessness paradigm and separated into 2 groups: non-learned helpless (NLH) and learned helpless (LH) mice, according to their number of failures out of 30 escapable shock trials, and the next day, learning and memory was assessed. a Timeline of the experiment. The percentage of a mouse’s total object exploration time spent exploring the familiar (F) and novel (N) objects (b, e) and the total time (s) mice spent engaged in exploration of both the familiar and novel objects combined (c, f) in the novel object recognition test were reported. Each dot represents a mouse. Two-way ANOVA F(2,24)_interaction = 7.334, F(1,24)_treatment = 15.83, F(2,24)_condition = 5.380 × 10⁻¹⁴, Bonferroni post hoc test, *p < 0.05, compared to % time spent with familiar object, bars represent means ± SEM, n = 4–12 mice/group. d, g The percentage of a mouse’s total maze exploration time spent exploring the start (S), familiar (F), and novel (N) arms in the two-trial Y-maze test was measured in a different cohort of mice than b and e. Each dot represents a mouse. Two-way ANOVA, F(4,81)_interaction = 5.807, F(2,81)_treatment = 9.980, F(2,81)_condition = 0.0, Fisher’s least significant difference test, *p < 0.05, bars represent means ± SEM, n = 4–13 mice/group