Postmortem MR imaging has revealed widespread deep White Matter pathology localized primarily in the frontal lobes. Histopathological staining will elucidate the nature of the abnormal WM signal revealed by MRI sequences; however, for the time being (in Phase 1), our main concern is histotechnical.
In other words, we expect that the tissue slices will be very fragile in the areas of the lesions. This is due to demyelination which appears to be quite extensive. The brain has been embedded in 10% gelatin and the block was subsequently cross-linked in 4% Formaldehyde solution. Gelatin embedding is intended to provide support and adhesion for those tissue portions that would detach in thin cross sections of tissue. Gelatin does not penetrate the tissue block; therefore, internal White Matter lesions will be a problem to contend with when the sections are being mounted on glass.