Microbiota influence the development of the brain and behaviors in C57BL/6J mice

Abstract

We investigated the contributions of commensal bacteria to brain structural maturation by magnetic resonance imaging and behavioral tests in four and 12 weeks old C57BL/6J specific pathogen free (SPF) and germ free (GF) mice. SPF mice had increased volumes and fractional anisotropy in major gray and white matter areas and higher levels of myelination in total brain, major white and grey matter structures at either four or 12 weeks of age, demonstrating better brain maturation and organization. In open field test, SPF mice had better mobility and were less anxious than GF at four weeks. In Morris water maze, SPF mice demonstrated better spatial and learning memory than GF mice at 12 weeks. In fear conditioning, SPF mice had better contextual memory than GF mice at 12 weeks. In three chamber social test, SPF mice demonstrated better social novelty than GF mice at 12 weeks. Our data demonstrate numerous significant differences in morphological brain organization and behaviors between SPF and GF mice. This suggests that commensal bacteria are necessary for normal morphological development and maturation in the grey and white matter of the brain regions with implications for behavioral outcomes such as locomotion and cognitive functions.

Immediate and delayed decrease of long term potentiation and memory deficits after neonatal intermittent hypoxia

“…MPF mapping is a validated biomarker of myelination in neural tissues. The method has high resolution, fast and independent of directional tissue organization, and therefore is uniquely suited to assess myelination in gray matter structures (Khodanovich et al, 2017; Lu et al, 2018; Yarnykh et al, 2015). MPF provided complementary information to diffusion tensor imaging in white and gray matter in this study.…”

“…The publicly available MRMNeAt atlas database was used, containing 10 individually labeled C57BL/6 J in vivo mouse brains. Twenty‐one white and gray matter structures from the atlas were mapped for each mouse brain (Lu et al, 2018). Volumes of individual anatomical areas and values of MPF were compared between control and IH groups.…”

Direct comparison between apparent diffusion coefficient and macromolecular proton fraction as quantitative biomarkers of the human fetal brain maturation

“…16,17 A newer quantitative MRI method, fast macromolecular proton fraction (MPF) mapping, 18,19 has been recently adapted to fetal brain applications. 20,21 MPF has been histologically validated as a myelin biomarker in animal models [22][23][24][25] and has shown the capability to quantify myelin damage in clinical studies of multiple sclerosis 26,27 and mild traumatic brain injury. 28 In the recent normal fetal 20 and pediatric 29 brain studies, MPF maps demonstrated close quantitative agreement with spatiotemporal trajectories of myelin development.…”

The microbiota promotes social behavior by modulating microglial remodeling of forebrain neurons

“…Ethics statement. All zebrafish experiments were approved by the University of Oregon Institutional Animal Care and Use Committee (protocols 18-08 and [18][19][20][21][22][23][24][25][26][27][28][29].…”

“…15 Mice raised germ-free (GF) or with an abnormal microbiota exhibit impaired social behavior, which is correlated with microbial modulation of neuronal gene expression, neurotransmitter levels, brain maturation, and myelination. [16][17][18][19][20][21][22] Host-associated microbes influence social behavior across taxa. For example, the Drosophila melanogaster microbiota promotes social preference through serotonergic signaling.…”