Fig. 2: Stratification of MIA-exposed offspring into resilient and susceptible subgroups.

A two-step cluster analysis incorporating the main behavioral measures (total distance moved in the open field, spontaneous alternation in the Y-maze test of working memory, social preference index in the social interaction test, and mean % PPI of the acoustic startle reflex) from individual control (CON; n = 77, originating from 12 litters) and poly(I:C)-exposed (POL; n = 81, originating from 12 litters) offspring was performed to identify subgroups with differing behavioral profiles. a Distribution of CON and POL offspring across the two clusters (CL1 and CL2) identified by two-step cluster analysis. The pie charts show the cluster distribution (in percentages, %) for all offspring combined, and for CON and POL offspring separately. The numbers in brackets represent the number of offspring in each cluster. b Summary of the relative predictor importance for cluster separation as revealed by two-step cluster analysis. c The scatter plots show the main behavioral readouts for subgroups of CON and POL offspring as identified by two-step cluster analysis. Compared to reference CON (Ref-CON, n = 72) and resilient POL (Res-POL, n = 38) offspring, susceptible POL (Sus-POL, n = 43) display a significant reduction in the social preference index (F_(2,150) = 101.0, p < 0.001; Sus-POL vs. Ref-CON or Res-POL: ***p < 0.001), mean % PPI in the PPI test of the acoustic startle reflex (F_(2,150) = 40.8, p < 0.001; Sus-POL vs. Ref-CON or Res-POL: ***p < 0.001) and spontaneous alternation in the Y-maze working memory test (F_(2,150) = 22.3, p < 0.001; Sus-POL vs. Ref-CON or Res-POL: ***p < 0.001), based on ANOVA and Tukey’s post hoc tests. d Distribution of CL1 and CL2 offspring across CON and POL litters (N = 12 for each treatment, L1–L12). Note that each POL litter concomitantly contained offspring identified as belonging to CL1 (representing Res-POL offspring) and CL2 (representing Sus-POL offspring).