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

• DOI: 10.1371/journal.pone.0201829
• Publication Date: 2018-08-03T15:59:49Z
• Authors: Jing Lu; Sylvia Synowiec; Lei Lu; Yueyue Yu; Talitha Bretherick; Silvia Takada; Vasily Yarnykh; Jack Caplan; Michael Caplan; Erika C. Claud; Alexander Drobysh...
• Keywords: магнитно-резонансная томография; Male; 0301 basic medicine; Science; мыши; Cell Count; 03 medical and health sciences; 0302 clinical medicine; Animals; Gray Matter; созревание головного мозга; Maze Learning; Social Behavior; Myelin Sheath; Spatial Memory; Neurons; комменсальные бактерии; Behavior, Animal; Microbiota; Q; R; Brain; Organ Size; микробиота; поведенческие тесты; Magnetic Resonance Imaging; White Matter; Specific Pathogen-Free Organisms; Mice, Inbred C57BL; Medicine; Female; Research Article

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.