Figures and data
Effect of perinatal and adult exposure to enrichment observed in adulthood.
(A) Schematics of the enriched environment (EE) and Standard Housing (SH). (B) Illustration of the datasets used in the paper. Dataset N (“neonatal”): Perinatal enrichment, neonates perfused at P7 for ex vivo MRI. N-EE: Neonates born in EE; N-SH: Neonates born in SH. Shaded because not used in this figure. Dataset P (“perinatal”): Perinatal enrichment until adulthood (6 weeks of enrichment), animals perfused at P43 for ex vivo MRI. P-EE: Animals born in EE. P-SH: Animals born in SH. Dataset A (“adulthood”): Animals in standard housing until P53, adulthood enrichment from P53 to P96 (6 weeks of enrichment). Animals perfused at P96 for ex vivo MRI. A-EE: Animals transferred to EE in adulthood. A-SH: Animals staying in SH in adulthood. More details are provided in the Methods section. (C) A voxel-wise linear model was applied to the Jacobians computed after linear co-registration (hence corrected for individual brain volume variation) coming from datasets P and A (see Methods). (left panel) Effect of EE in adulthood regardless of the timing of enrichment. The regressors are housing condition and sex. (right panel) Differential effect of perinatal vs adulthood enrichment. The regressors are housing, age and sex, and the interaction term housing*age. (D) z-scored regional volumes, normalised by total brain volume (only male volumes shown to address the sex discrepancy between datasets P and A). Data are zeroed to the mean of the standard housing condition in their age group. The z-score is calculated using the mean and the standard deviation is shared over datasets P and A. The error bars represent the lower and upper confidence limits.
Effect of perinatal exposure to enrichment observed at P7.
(A) Effect of EE in neonates (P7). A linear model was applied to the Jacobians computed after linear co-registration (hence corrected for individual overall brain volume variation), with the following housing condition, litter order, litter size and sex as regressors. The effect of housing condition is shown with a FDR threshold at 5%. (B) Datasets of the paper with timings of exposure (c.f. caption Figure 1B). Data in this figure come from the dataset N. (C) z-scored regional volumes normalised by total brain volume, and z-scored total brain volumes (only male volumes shown to be consistent with datasets shown in Figure 1D). Data are zeroed to the mean of the standard housing condition. The z-score is calculated using the mean. The error bars represent the lower and upper confidence limits.
Effect of housing on maternal behaviour and its relation to P7 brain structure.
(A) Schematic experimental design. (B) Maternal contact time and time spent actively nursing the offspring per condition for each observation. C. Maternal contact time for dams that changed housing conditions between Litter 1 and Litter 2. (D) Voxel-wise t-statistics of the effect of housing (EE vs. SH, left) and maternal behaviour (Total Contact, middle) on brain volume, as well as both contrast overlayed on top of each other to emphasize similarities. (E) Z-score of the t-stats for each voxel from the voxel-wise brain analysis for housing and maternal behaviour plotted against each other and showing a strong correlation. (F) In an exemplary striatal ROI, in which enrichment led to a decreased volume, higher contact time of dams with their neonates predicted lower volume size (r= −0.4014).
Summary of hypotheses and results.
Males only in P-data
Effect of Litter Size and Litter order at P7(N)
(N-P-A-P|A) housing comparison
Maternal care, perinatal enrichment and volumetric changes in P7 brains.
(A) Experimental design for assessing maternal care and brain stricture at P7. (B) Quantity of observed maternal contact time per housing (Triangle is EE) for the 1st and 2nd Litter. (C) Quantity of observed active nursing time per housing for the 1st and 2nd Litter for each dam. D. Quantification of additional maternal contact behaviors per condition E. Relationship between Total contact time of mums with the neonates and the number of neonates in the litter. F. Volumetric change in Brain stem ROI plotted against total contact time of the damn during the observed time period (r = 0.25)
Overview of subjects numbers in different dams (Cage A-2) and Litter (1 or 2) in the sample of P7 old pubs scanned ex vivo.
Volumetric changes due to enrichment. Slice number corresponds to presentation in Figure 1 and Figure 2.
Text colour indicates direction of change (Increase:red; decrease: blue)
