Charlotte Marchadour1, 2, Vincent Lebon1, 2, Julien Valette1, 2
1CEA-MIRCen, Fontenay-aux-Roses, France; 2CEA-CNRS URA 2210, Fontenay-aux-Roses, France
Transport of molecules within cells is a key process that can be achieved either passively by random diffusion, or by active transport (e.g. cytoplasmic streaming). The relative contribution of passive and active transport mechanisms to the ADC of intracellular metabolites and intracellular water is still debated. We investigate metabolite motion in the rat brain using diffusion-weighted spectroscopy with oscillating gradients. The dependence of metabolite ADC on the diffusion frequency is observed for the first time, making random diffusion emerge as the dominant transport mechanism. Subsequent data modeling further rules out the plausibility of significant active transport.