Neurofibrils are intermediate filaments arranged in bundles that run through the cell body and the processes of nerve cells . Already detectable in the early embryonic period, they are a shape-specific feature of nerve cells, which, in contrast , has not been confirmed in the case of the stem forms of nerve cells, the neuroblasts , and those of the glial cells , the glioblasts .
Staining and histology
Nerve cells can be represented in the preparation by staining their neurofibrils with a staining method practiced and described for the first time by Camillo Golgi around 1870 with the help of silver salts, but this only works in certain cases and in about every hundredth cell - and not in vivo . The in vivo thread-like protein molecules of the neurofibrils, on the other hand, can only be detected with an electron microscope.
Physiology and Pathophysiology
The functional significance of the tangles after a time they long as the substrate of the intracellular conduction were considered, now unknown again. For Alzheimer's disease, however, a characteristic change in its neurofibrils, which attach to so-called plaques (Alzheimer's fibril degeneration), has been proven. These are cytoplasmic lesions in the area of the perikaryon in the large and medium-cell pyramidal cells of the neocortex and paleocortex . In the electron arises a tangle of helically twisted protoplasm represents filaments having a diameter of 10 nm have. With these threads, a “biochemical relationship” to the normal intraneuronal neurotubules can be inferred due to their mutual readiness to react with certain antibodies .
- ↑ Norbert Ulfig: Short textbook histology. Georg Thieme Verlag, Stuttgart, ISBN 3-13-135572-7 , p. 63.
- ↑ Alfred Benninghoff , Kurt Goerttler .: Textbook of human anatomy. Volume 3: Nervous System, Skin and Sensory Organs. 7th edition. Urban & Schwarzenberg, Munich 1964, p. 76 f.
- ↑ Manfred Spitzer : Spirit on the Net. Models for learning, thinking and acting. Spektrum Akademischer Verlag, Heidelberg 1996, ISBN 3-8274-0109-7 , p. 3.
- ↑ Max Watzka : Short textbook of the histology and microscopic anatomy of humans. 3. Edition. FK Schattauer, Stuttgart 1964, pp. 65 and 69.
- ^ Michael Allard, Jean Louis Signoret, Dirk Stalleiken: Alzheimer dementia. Springer-Verlag, Berlin 1988, ISBN 3-540-18285-3 , p. 17 f.