Influence of fixation and histological procedure on the morphometric parameters of neuronal cells

The influence of fixation and histological procedure on morphometric parameters of human and rat brains were analyzed. We found negative correlation of brain weight with the fixation time both in human and rat material. Human brains fixed for shorter period of time than one year showed large differences in weight. The group of brains fixed for longer than one year was characterized by much smaller dispersion. Moreover, we found that during histological preparation the shrinkage of brain tissue of older human subjects is statistically significantly smaller than younger ones (below 65 years). In order to correct these artifacts easily we propose three simple formulas.