Different volume changes of cerebral cortex and white matter during histological preparation

In quantitative neuroanatomy and neuropathology, large neuronal systems are frequently analyzed on the basis of small tissue blocks thus assuming that the volume changes of the various compartments of the tissue block can be corrected by an overall factor. 228 blocks of cerebral cortex and white matter of the frontal lobe, thalamus, and striatum were prepared from 13 human brains and embedded in paraffin. The mean shrinkage in the paraffin sections was found to be 51% for the cerebral cortex and 42% for the white matter. Therefore, an overall correction factor tissue blocks both with cerebral cortex and white matter results in an underestimation of cerebral cortex and an overestimation of white matter.