Prof. Dr. Karl Meller

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The Junctional complex of choroid epithelial cells was studied during in vivo formation, disaggregation after trypsin treatment, and in vitro reaggregation. The in vivo formation begins with the occurrence of amorphous patches of particles followed by the formation of small particulate rows and polygonal-ordered particle assemblies. Further arrangement of(More)
Cytoskeletal alterations in the cytoplasm of chromatolytic neurons of the dorsal root ganglia were studied in chickens after transection of the sciatic nerves. These studies were carried out using cryofixation with a nitrogencooled propane jet. By this method, the morphological complexity of the cytoskeleton in normal perikarya and cell processes can be(More)
The ultrastructure of the optic and trigeminal nerves of the rat, cryofixed by use of a liquid nitrogenpropane jet, was examined, paying special attention to the myelin sheath and the cytoskeleton of the axoplasm. The cytoskeleton of the axoplasm is formed by a meshwork of neurofilaments and microtubules connected both to each other and also to the cell(More)
Dorsal root ganglia of chick embryos were cultured for one to four weeks on Maximow-slides. Puromycin was added to cultures for a pulse of 30′ in a dose of 100 μ/ml medium. Particular interest was given to the ultrastructural features of the glia-neuron relations. Puromycin caused a shrinkage of the glial processes and consequently the continous glial(More)
Isolated synaptic terminals were rapid-frozen with a liquidpropane jet, deep-etched, and rotary-shadowed replicas produced. The replicas show a three-dimensional view of the cytoplasmic components. Intraterminal mitochondria display a rough inner membrane with numerous stalked globular particles. Microfilaments connect the diverse organelles of the nerve(More)
Alterations in the cytoskeleton were studied in the axoplasm of neurites at the tips of proximal stumps of transected chicken sciatic nerves. The studies were carried out using cryofixation with a nitrogen-cooled propane jet. The most immediate effect is the almost complete disassembly of axoplasmic microtubules. This consequently causes the axonal(More)
Fixed retinae of chick embryos and chicks of the first week after hatching were fractured and examined with the scanning electron microscope. The matrix cells of the retina proliferate up to the beginning of the second week. The migrating cells are oriented in cell cords. This columnar organization prevails up to the development of the plexiform layers(More)
Cerebella of 3- to 6-week-old chickens were cryofixed in a nitrogen-cooled propane jet, deep-etched and rotary-shadowed. The use of a brief perfusion of 0.32 M sucrose improved the quality of the cryofixation and allowed the study of the deeper layers of the cerebellar cortex. It is reported that the cytoskeleton of the Purkinje cells (PC) shows distinct(More)
Dorsal root spinal ganglia of chick embryos were trypsinized and the cellular components isolated. Suspensions of these cells reaggregate. During this process satellite glial cells and neurons established intimate contacts. The reconstructed glial envelopes around the neurons are morphologically similar to the ones formed in the intact animal during(More)
Retinae of chick embryos and chicks one to six weeks after hatching were examined in ultrathin sections and in freeze-etch specimens. The development of the synaptic contacts between receptor cells and bipolar cells starts at the end of the second week of incubation with the enclosure of the dendritic prolongations, invaginating receptor terminals(More)