The rat neuroblastoma B104 cell line, which originated in the central nervous system, was able to proliferate in the absence of serum in synthetic medium supplemented with insulin, transferrin, progesterone, selenium, and putrescine. When added individually, each supplement had little or no effect; however, in combination there was a marked synergistic effect on cell number. The cells attained the same saturation density in this medium as in medium with 10% fetal calf serum added. More extensive process formation was observed in the supplemented medium, and other differentiated properties were retained as well. Synthetic media generally require serum supplementation to support the proliferation or survival of cultured cells. The inclusion of serum, however, may significantly affect experimental reproducibility, because batch variations occur as a result of differences in donor age, sex, nutrition, and physiological state even in pooled serum samples. In addition, the complex undefined nature of serum is a complication when assessing the effect(s) of regulatory agents, such as hormones or neurotransmitters, on differentiated properties of nervous system cells in culture. This is particularly important for long-term studies, because if serum is deleted a substantial reduction of cell numbers, and in many cases complete cell death, may occur within hours or a few days.In order to circumvent these problems, several cell lines have been adapted to proliferate in serum-free media (1-4). How The B104 rat neuroblastoma, a cell line of central nervous system origin, exhibits many of the properties characteristic of differentiated neurons, such as generation of action potentials, synthesis of neurotransmitters, and presence of neurotransmitter receptors and the neuron-specific 14-3-2 protein (9, 10). Furthermore, B104 cells, like C1300 neuroblastoma cells (11, 12), respond to removal of serum by rapidly extending neurites, a phenomenon that has been correlated with the preceding neuronal properties (9).In this communication we report that B104 cells can proliferate in a serum-free synthetic medium supplemented with insulin, transferrin, progesterone, selenium, and putrescine (N2 medium). More extensive process formation is seen in N2 than in serum-supplemented medium, and other differentiated properties have been retained as well. METHODS AND MATERIALSCell Culture. The rat neuroblastoma B104 cell line was obtained from D. Schubert of the Salk Institute, La Jolla, CA. Stock cultures were maintained in a 1:1 mixture of Ham's F12 medium and the Dulbecco-Vogt modification of Eagle's medium (DME) supplemented with 5% (vol/vol) horse serum; 2.5% (vol/vol) fetal calf serum; 1.2 g of NaHCO3 per liter; 15 mM Hepes buffer; and 40 mg of penicillin, 8 mg of ampicillin, and 90 mg of streptomycin per liter. Triple-distilled water was used to prepare media. Stock cultures were grown in flasks (Falcon Plastics 3013, 25-cm2 surface area) in 4 ml of medium in a humidified atmosphere of 5% C02/95% air at 370C and subcultured every ...

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Growth requirements in vitro of oligodendrocyte cell lines and neonatal rat brain oligodendrocytes Branch, Galveston, TX 77550-2772 Communicated by Gordon H. Sato, November 15, 1985 ABSTRACT I have defined the basic requirements for the proliferation of cell lines expressing oligodendrocyte properties and for the survival of galactocerebroside-positive oligodendrocytes derived from neonatal rat brains. Conventional serum-containing medium can be replaced by 01 medium, a chemically defined medium supplemented with insulin, transferrin, sodium selenite, and biotin. Thyroid hormone is not required. When cells are plated directly into 01 medium, the substratum has to be modified by precoating with polylysine and adding fibronectin to the medium prior to the cells. Both cell lines and brain cells can be subcultured numerous times in 01 medium without initial culture in serum-containing medium. Brain cultures can be maintained in 01 medium for several months and contain a significantly higher percentage of mature oligodendrocytes, a lower number of astrocytes, and no fibroblasts as compared to cells maintained in serum-containing medium.

Human fetal neural stem cells (hNSCs) can be expanded in vitro by mitogens or growth factors, such as basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and/or leukemia inhibitory factor (LIF). Their effects on proliferation rate and differentiation pattern of hNSCs, however, have not been fully characterized. In this study, we cultured hNSCs in seven regimens, including bFGF, EGF, and LIF, either alone or in combinations. Cells were maintained as neurospheres in treatment media for various periods, up to six passages. A combination of bFGF, EGF, and LIF expanded hNSCs more efficiently than any other treatment as determined by counting total cell numbers using a trypan blue exclusion assay, a WST-1 cell viability assay, and a bromodeoxyuridine incorporation flow cytometric analysis. Differentiation patterns of hNSCs expanded under different conditions were also analyzed. We reported previously that hNSCs primed in vitro with a combination of bFGF, heparin, and laminin (FHL) induced neuronal differentiation toward a cholinergic phenotype. In this study, we show that the FHL priming increases neuronal differentiation while decreasing astroglial generation in all treatment groups as determined by immunostaining. However, cells proliferated under different growth factor conditions do vary in their phenotypic differentiation patterns. Particularly, significant generation of cholinergic cells was observed only in hNSCs expanded with EGF/bFGF or EGF/bFGF/LIF, but not with other treatment regimens, even when they are exposed to the same priming procedure. Our results indicate that hNSCs are highly plastic, with their proliferation and differentiation potential dependent on different growth factor treatments.

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We report that cell survival after neurite transection in a mammalian neuronal model (cultured B104 cells) critically depends on somal [Ca2+]i, a novel result that reconciles separate long-standing observations that somal survival decreases with more-proximal axonal transections and that increased somal Ca2+ is cytotoxic. Using fluorescence microscopy, we demonstrate that extracellular Ca2+ at the site of plasmalemmal transection is necessary to form a plasmalemmal barrier, and that other divalent ions (Ba2+, Mg2+) do not play a major role. We also show that extracellular Ca2+, rather than injury per se, initiates the formation of a plasmalemmal barrier and that a transient increase in somal [Ca2+]i significantly decreases the percentage of cells that survive neurite transection. Furthermore, we show that the increased somal [Ca2+]i and decreased cell survival following proximal transections are not due to less frequent or slower plasmalemmal sealing or Ca2+ entry through plasmalemmal Na+ and Ca2+ channels. Rather, the increased somal [Ca2+]i and lethality of proximal neurite injuries may be due to the decreased path length/increased diameter for Ca2+ entering the transection site to reach the soma. A ryanodine block of Ca2+ release from internal stores before transection has no effect on cell survival; however, a ryanodine- or thapsigargin-induced buildup of somal [Ca2+]i before transection markedly reduces cell survival, suggesting a minor involvement of Ca2+-induced release from internal stores. Finally, we show that cell survival following proximal injuries can be enhanced by increasing intracellular Ca2+ buffering capacity with BAPTA to prevent the increase in somal [Ca2+]i.

A previously described serum-free, defined medium (G2 medium) containing transferrin, selenium, hydrocortisone, biotin, fibroblast growth factor (FGF) and fibronectin developed for the growth of human and rat derived glioma cells was investigated for its ability to support proliferation of astrocytes in primary cultures of neonatal rat cerebrum. These cells were able to grow in G2 medium. Enhanced proliferation and repeated subcultivation were obtained after adding insulin and/or epidermal growth factor (EGF) to the G2 medium at concentrations of 5 μg/ml and 10 ng/ml, respectively. In these modified media (called G4 and G5 medium) astrocytes showed a higher degree of morphological differentiation as compared to serum supplemented medium. Cell type specificity was determined by immunocytochemical staining of glial fibrillary acidic (GFA) protein, which could already be demonstrated 5 days after plating cells. G4 and G5 represent the first serum-free defined media in which astrocytes proliferate and differentiate without preceding or intermediate contact to serum supplemented medium. Modification of the culture substratum by adding hyaluronic acid and chondroitin sulfate A to G4 medium (G2 medium + insulin) enhanced proliferation of astroglial cells by a factor of about 1.5. In the presence of epidermal growth factor no response to the altered culture dish surface was observed and the addition of fibronectin, otherwise a stringent plating requirement, was no longer necessary.