Synaptogenesis and myelinogenesis in dissociated cerebral cells from rat embryo on polylysine coated surfaces

Abstract

The appearance of myelinated axons and establishment of synaptic contracts in dissociated cells from rat embryo cerebral hemispheres grown on polylysine precoated surfaces were studied by light and electron microscopy. Typical myelin lamellae ensheathing axons were observed as early as the eighth day. Immature synaptic profiles exhibiting slight membrane thickening and few synaptic vesicles were observed after seven days. At 3 weeks, mature synapses containing many synaptic vesicles and the typical irregular membrane thickening could be seen. It is suggested that the presence of polylysine may provide a support which enhances the attachment and subsequent establishment of contacts between neuronal and glial cells, resulting in the early onset of myelin formation.

Immunofluorescent Patterns of Dissociated Rat Embryo Cerebral Cells during Development in Surface Culture: Distinctive Reactions with Neurite and Perikaryon Cell Membranes

“…This conclusion is also supported by their ultrastructural characteristics [Yavin and Yavin, 1977] and their ability to extend neuritic processes. For mation of the latter appears to be accom panied by a progressive acquisition of new antigenic determinants ( fig.…”

“…On the other hand the im munofluorescent-heterotypic aggregate (fig. 4, upper left corner), which is composed of a layer of cells characterized by their ruffled membrane [Yavin and Yavin, 1977], is exten sively labeled. Figure 4 also shows that in contrast to the ring fluorescence of the neu ronal cell body (arrow), its extended axon containing numerous varicosities is totally unlabeled by anti-embryo brain serum.…”

“…Dissociated embryonic brain cells grown in suspension culture [DeLong and Sidman, 1970;Moscona, 1974] or on a solid support [for references see Mandel et al, 1976] resemble in many re spects the cellular segregation and organiza tion into distinct arrays which represents the hallmark of brain histogenesis. Aggregation under culture conditions appears to be an essential step for the establishment of inter cellular cooperativity and may be largely re sponsible for the ability of cells to express their functional properties [Seeds, 1971;God frey et al, 1975], In a previous study we have shown that the aggregation process in surface brain cell cultures predates the appearance of axonal and dendritic extensions as well as the establishment of synaptic contacts and forma tion of myelin [Yavin and Yavin, 1977]. While a great deal of experimental evidence has been accumulated on the histotypic organiza tion of cells in suspension cultures [Garber and Moscona, 1972a,b], little information is presently available as to the cell types com prising the cerebral aggregate as it evolves under surface culture conditions [Benda et a!., 1975].…”

Low Doses of <i>L</i>-Monosodium Glutamate Promote Neuronal Growth and Differentiation in vitro

“…This could indicate an increased synthesis of ex portable proteins, correlating with the in creased number of synaptic vesicles and of synapses. A finding we have interpreted as a sign of neuronal maturation and advanced development in vitro [9,39,40].…”

Oligodendroglia development in cell culture as monitored with a monoclonal antibody

“…The susoension was in&x&d for 12 rnin at 3?C, dispersed by gent& &petting in basal Eagle's medium (BEM) with 10% fetal calf serum (FCS), and passed through a 200 gm Nylon screen. Surface cultures were prepared from the dissociated cells by pipetting them onto 18 mm glass wverslips previously coated with poly-(D-lysine) (Yavin and Yavin, 1977). The cultures were maintained at 37°C in a 5% C02:95% air incubator.…”