Significant Reduction in ADC During Enhanced Neuronal Activity in Isolated Spinal Cord of Newborn Rat

Nitzan Tirosh¹, Uri Nevo²

Isolated and viable spinal cords of newborn rats were used to investigate whether the changes in DWI signal during neuronal activation originate from biophysical mechanisms linked to neuronal activity or related to vascular effects. DW images were acquired with three diffusion times and along three diffusion directions during three physiological phases: Spontaneous activity, chemically induced enhanced activity and return to baseline activity. Reduction of 18-27% in the average ADC was observed during elevated neuronal activity. These results suggest that electrical activity affects water displacement in neurons and these changes are not an MR artifact due to a vascular effect.