Investigating changes in brain lactate compartmentation using diffusion-weighted MRS in APP/PS1 mice

Diffusion-weighted MR spectroscopy yields information about the microstructure of the environment where brain metabolites are diffusing. Here, we measure the diffusion of two purely intracellular metabolites (astrocytic myo-inositol and neuronal N-acetyl aspartate) and of lactate, which is also present in the extracellular space, in the cortex of 12-month-old APP/PS1 and control mice. While astrocytic and neuronal microstructures appear unchanged in APP/PS1 mice, lactate diffusion appears slower. Modeling DW-signals suggests decreased extracellular lactate fraction.