Steady-state distribution of lithium during cultivation of dissociated brain cells

Summary The formation of a steady-state intracellular lithium level was studied in the course of cultivation of dissociated nerve cell cultures obtained from chick embryonic brains. When lithium was given at a concentration of 2 mM, in the nutrient medium, at day 5, a steady state intracellular lithium content was achieved after about 30 min of incubation and it did not change significantly during the time of cultivation up to the 13th day in vitro.Acknowledgment. We thank Dr Latzkovits for useful advice and helping in methodology.     

A comparative study of the differentiation of dissociated nerve cells under different culture conditions

Summary In vitro differentiation of chick embryo brain cells was compared under several culture conditions. Morphological observations and acetylcholinesterase histochemical staining revealed that the development was similar in all conditions tested if cells have been derived from 7 days embryos. Considering the cultures from 11 days embryos, the cell dissociation by trypsin and the plastic surface proved to be the most favourable conditions in contrast to mechanical dissection and collagen surface.M. Sensenbrenner is Maitre de Recherche au CNRS.     

A new substrate for cultures of dissociated primary rat brain

Different substrates were used to coat plastic petri dishes for the cultivation of dissociated fetal rat brain cells. Only on surfaces which were coated with a mixture of serum and non-reconstituted collagen, did the majority of the inoculated cells attach singly or as aggregates within 24 h. The attachment of the cells was followed by the outgrowth of cellular processes either from single cells or from aggregates in the same time period. This did not occur on collagen or serum treated or on regular plastic dishes. Under the latter conditions a similar outgrowth was observed only after 3–5 days.     

A comparative study of the differentiation of dissociated nerve cells under different culture conditions.

In vitro differentiation of chick embryo brain cells was compared under several culture conditions. Morphological observations and acetylcholinesterase histochemical staining revealed that the development was similar in all conditions tested if cells have been derived from 7 days embryos. Considering the cultures from 11 days embryos, the cell dissociation by trypsin and the plastic surface proved to be the most favourable conditions in contrast to mechanical dissection and collagen surface.     

Histochemical study of dissociated nerve cells from embryonic chick cerebral hemispheres in flask cultures

Zusammenfassung Die Differenzierung von dissoziierten Grosshirnneuronen in Plastikflaschenkulturen wurde mit histochemischen Methoden, Nisslfärbung, Silberimprägnation der Nervenfasern und Acetylcholinesteraseaktivität untersucht.

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with the technical assistance ofM. F. Knoetgen

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Chargée de Recherche au C.N.R.S.     

Evidence for the presence of viable endothelial cells in cultures derived from dissociated rat brain

Summary The morphology and histochemistry of dissociated newborn rat brain was studied in tissue culture. Direct microscopy of developing cells, electron microscopy and the alkaline phosphatase activity were used to identify the capillary endothelial cells.Acknowledgments. We thank Dr J. Gripenberg for technical assistance. This research was supported by Finnish Cultural Foundation and carried out during the tenure of a fellowship provided for F. J. from the Finnish-Hungarian Cultural Exchange Program.     

A simple approach to the toad's (Bufo melanostictus) nerve muscle preparation.

A simple and modified dorsal approach method has been made in the toad's (Bufo melanostictus) sciatic gastrocnemius nerve-muscle preparation. This method incurs less blood loss, time consumption, nerve damage and visceral spoil compared to conventional ventral approach method.     

The effect of concanavalin-A on the reaggregation of cells dissociated from Xenopus laevis early embryos

Summary The effects of concanavalin-A on the reaggregation and sorting of cells from Xenopus laevis early embroys have been studied. The results suggest that at high concentrations, concanavalin-A can prevent reaggregation.     

Two different aggregation principles in reaggregation process of dissociated sponge cells (Geodia cydonium)

Zusammenfassung Chemisch dissoziierte Zellen des KieselschwammesGeodia cydonium reaggregieren aufgrund zweier verschiedenr Reaggregationsprinzipien. Der Aggnegationsfaktor, auf den die Primäraggregation zurückgeht, ist membrangebunden und wird durch Proteasen nicht inaktiviert. Der sekundäre Aggregationsfaktor wurde 500fach angereichert. Das Molekulargewicht dieses Aggregationsfaktors beträgt etwa 20000 Daltons; er ist mit einem ringförmigen Makromolekül (2×10⁹ Daltons) assoziiert.

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Acknowledgments. We wish to thank Mrs.V. Pondeljak, Mrs.U. Müller-Berger, Mr. R. Beyer andMr. M. Srecec for their excellent technical assistance. We gratefully acknowledge the advice of dipl. Chem.J. Obermeier for the carbodiimide coupling method. This work is supported by Fonds der Chemischen Industrie and by the Landesversicherungsantalt Rheinland-Pfalz, Speyer/Rh.     

Regeneration of cartilaginous matrix from the dissociated chondrocytesin vitro

Zusammenfassung Aus 8 Tage alten Hühnerembryonen wurden durch Verdauung der intrazellulären Matrix des differenzierten Knorpelgewebes dissoziierte Chondrozyten gewonnen. Diese Chondrozyten schlossen sich wieder zu Kolonien lose gepackter sphärischer Zellen zusammen. Durch Regeneration der interzellulären Matrix bildete sich in den Organkulturen solcher Reaggregate die ursprüngliche Knorpel-Architektur wieder aus.

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(on leave of absence from the Zoological Institute, Faculty of Science, University of Kyoto, Japan), December 12, 1958.