Sex- and brain region-specific alterations in brain volume in germ-free mice

Shawna L Thompson; Jacob Ellegood; Dawn M E Bowdish; Jason P Lerch; Jane A Foster

doi:10.1016/j.isci.2024.111429

Sex- and brain region-specific alterations in brain volume in germ-free mice

iScience. 2024 Nov 19;27(12):111429. doi: 10.1016/j.isci.2024.111429. eCollection 2024 Dec 20.

Authors

Shawna L Thompson¹, Jacob Ellegood², Dawn M E Bowdish³, Jason P Lerch^{2

4}, Jane A Foster^{1

5

6}

Affiliations

¹ Psychiatry and Behavioural Neuroscience, McMaster University, Hamilton, ON, Canada.
² Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada.
³ Department of Medicine and McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada.
⁴ Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford UK.
⁵ Research Institute at St. Joe's Hamilton, Hamilton, ON Canada.
⁶ Center for Depression Research and Clinical Care, Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.

Abstract

Several lines of evidence demonstrate that microbiota influence brain development. Using high-resolution ex vivo magnetic resonance imaging (MRI), this study examined the impact of microbiota status on brain volume and revealed microbiota-related differences that were sex and brain region dependent. Cortical and hippocampal regions demonstrate increased sensitivity to microbiota status during the first 5 weeks of postnatal life, effects that were greater in male germ-free mice. Conventionalization of germ-free mice at puberty did not normalize brain volume changes. These data add to the existing literature and highlight the need to focus more attention on early-life microbiota-brain axis mechanisms in order to understand the regulatory role of the microbiome in brain development.

Keywords: Microbiome; Neuroscience.