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Selected Publication:
Tafrali,D.
Post-mortem changes and autolysis in frontal lobe cells of Sus scrofa
Humanmedizin; [Diplomarbeit] Medical University of Graz;2019. pp. 64
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- Authors Med Uni Graz:
- Advisor:
- Leitinger Gerd
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- Abstract:
- Introduction Publications on post-mortem changes and autolysis in mammalian frontal lobe cells are scarce, especially when it comes to its early mechanisms. This thesis therefore contributes to the fundamental understanding of post mortal neuronal (and glial) cell death through autolysis. Material and methods We used one specimen of the eurasian domestic pig as our study animal. After the pig was killed, we prepared tissue samples from its frontal lobe in a post-mortem interval (PMI) of 0, 3, 6 and 12 h. At every point in time, we fixed the tissue with a mixture of glutaraldehyde and formaldehyde. Afterwards it was fixed again with osmium tetroxide to finally be embedded in TAAB embedding resin. Subsequently the sample was thin sectioned and contrasted with platinum blue and lead citrate. To analyse the samples, we used transmission electron microscopy. Aims The aim was to carry out the criteria for post-mortem autolysis as well as to use these criteria to investigate to which degree post-mortem autolysis in frontal lobe cells of the Eurasian domestic pig occurs. Results Ultrastructural alterations of 51 frontal lobe neurons, astrocytes and oligodendrocytes were investigated. After 12 h the diameter of neuronal cells tended to decrease (neurons: 12,61 μm to 11,25 μm; pyramid cells: 23,15 μm to 14,24 μm) while glial cells rather gained in diameter (astrocytes: 8,9 μm to 12,4 μm; oligodendrocytes: 9,73 μm to 10,41 μm). Chromatin condensation occurred in all frontal lobe cells beginning at 3 h. Complete ribosome detachment from the rER was not found in nearly any investigated cell (1:51 overall). Vacuolization of the cytoplasm was first seen at 3 h. The occurrence of lysosomes was high throughout the PMIs in all cells (84.6 % at 0 h to 100 % at 12 h). Discussion This descriptive work confirms several autolytic ultrastructural changes in neural and glial cells described in other study animals. Chromatin condensation, neurons shrinking, glial cells swelling, intracytoplasmic vacuolization and the occurrence of lysosomes are valid indicators for autolysis. The occurrence of rER without any ribosomes and structural disintegration of all mitochondria are comparatively unreliable markers for autolysis.