Study of brain white matter anisotropy

An in vitro study to detect brain white matter anisotropy is presented. Porcine cylindrical samples were compressed (0.5 mm/mn) in a testing apparatus composed of a testing machine combined with a precision balance. Two different types of samples were harvested: 1) cut in parallel and 2) perpendicular to axon fibers present in white matter. For an elongation of 0 to 25% white matter exhibited isotropy. For deformation superior to 25%, the load versus elongation curves diverged increasingly, just to a difference of 37% between the samples of the two perpendicular directions for 35% of elongation, respectively.