DW-MRI of perfused and thermally controlled neuronal organotypic cultures

Objectives Signal attenuation in Diffusion Weighted MRI (DW-MRI) of the brain originates from multiple sources [1] that are being studied extensively, in order to quantify their relative contributions to the DW-MRI signal in health and disease. Recently it was also suggested that some of these mechanisms can be used to detect neuronal activity directly by DW-MRI [2]. However, sources of physiological ‘noise’ such as bulk motion of the tissue, or flow of oxy/non-oxygenated blood, complicate the study of the physical origins of DW-MRI signal in-vivo, and the interpretations of signal changes. To address the question of biophysical origins of DW-MRI signal, while avoiding the use of fixed tissues or of in-vivo experiments, we use the experimental model of neuronal organotypic cultures. We mimic the physiological conditions by continuously perfusing the tissue, and maintaining it near physiological temperature.