[Postmortem changes in the ultrastructure, cytoplasmic proteins and nuclear chromatin of rabbit nerve cells]

Changes in the set of water soluble cytoplasmic and chromatin proteins have been studied in the rabbit neocortex, cerebral trunk, liver and muscles by means of electrophoresis in polyacryl gel with sodium dodecisulfate, 12 and 24 h after the animals are decapitated, when the material is kept in cold and at room temperature. Ultrastructure of pyramidal neurons in layer V of the rabbit sensomotor cortex has also been studied immediately after death and after 24 hours' preservation of the material at 4 degrees C and at room temperature. It has been stated that the ultrastructural changes in the nucleus and in the set of chromatin proteins in the cerebral cells are rather small even 24 h after death. Cytoplasmic structure and spectrum of the cytoplasmic proteins undergo much greater changes. Chromatin proteins of the cerebral cell nuclei, especially those of the neocortex, much better withstand the postmortem proteolysis than the cells in the liver and muscles, and cytoplasmic proteins of the cerebral cells are less stable than in other tissues. A possibility to perform analogous investigations in section material of the human brain and possible mechanisms of adaptive character on unequal stability of proteins in various tissue cells are discussed.