Individual behavioral trajectories shape whole-brain connectivity in mice

Abstract

It is widely assumed that our actions shape our brains and that the resulting connections determine who we are. To test this idea in a reductionist setting, in which genes and environment are controlled, we investigated differences in neuroanatomy and structural covariance by ex vivo structural magnetic resonance imaging (MRI) in mice whose behavioral activity was continuously tracked for 3 months in a large, enriched environment. We confirmed that environmental enrichment increases mouse hippocampal volumes. Stratifying the enriched group according to individual longitudinal behavioral trajectories, however, revealed striking differences in mouse brain structural covariance in continuously highly active mice compared to those whose trajectories showed signs of habituating activity. Network-based statistics identified distinct sub-networks of murine structural covariance underlying these differences in behavioral activity. Together, these results reveal that differentiated behavioral trajectories of mice in an enriched environment are associated with differences in brain connectivity.

Age-related changes in layer II immature neurons of the murine piriform cortex

“…Stem celldriven adult neurogenesis is a developmental process particularly useful during juvenile stages of the animal lifespan (Ben Abdallah et al, 2010;Sanai et al, 2011;Sorrells et al, 2018;Snyder, 2019;Bond et al, 2022). It supports the postnatal growth of the brain and the refinement of its neural circuits based on experience (Semënov, 2019;Seki, 2020;Kempermann et al, 2022;Bogado Lopes et al, 2023), but undergoes a progressive depletion of neural stem cells and/or entry in a quiescent state during adulthood (Encinas et al, 2011;Urbán et al, 2019). As such, it is different from the continuous cell renewal maintaining homeostasis in other stem cell systems of the body through the entire lifespan (Semënov, 2019).…”

Investigating brain alterations in the Dp1Tyb mouse model of Down syndrome

“…Then, QUIT qi mp2rage was used to create uniform T1-weighted images and T1 relaxation time maps. To assess brain volume and T1 changes, tensor-based morphometry and atlas-based analysis —using a modified version of the Allen Mouse Brain Atlas consisting of 72 regions of interest generated by combining related regions of the original atlas ( Wang et al, 2020 ; Mueller et al, 2021 (see Supplementary Table 1 ) — were performed on these images as previously described ( Bogado Lopes et al, 2023 ; Mueller et al, 2021 ) and detailed in the Supplementary Methods .…”

Investigating Brain Alterations in the Dp1Tyb Mouse Model of Down Syndrome

“…Then, QUIT qi mp2rage was used to create uniform T1-weighted images and T1 relaxation time maps. To assess brain volume and T1 changes, tensorbased morphometry and atlas-based analysis -using a modified version of the Allen Mouse Brain Atlas consisting of 72 regions of interest generated by combining related regions of the original atlas (Wang et al, 2020;Mueller et al, 2021(see Supplementary Table 1) -were performed on these images as previously described (Bogado Lopes et al, 2023;Mueller et al, 2021) and detailed in the Supplementary Methods.…”