Nerve cells cell culture

In contrast to the functional information available for the roles of ACh and AChE, the function or functions of RBC and serum ChEs are still matters for speculation. One idea is that they protect the body from natural anti-ChE agents (e.g., phyosos-tigmine) encountered during the evolution of the species another idea is that they have specific but still unknown roles in tissues. For example, there are reports that inhibition of BuChE activity blocks adhesion of neurites from nerve cells in culture and that AChE promotes outgrowth of neurites as if the enzymes had roles in cell adhesion and differentiation. 

Electric field was applied with microelectrodes as illustrated in Figures 3 and 4. In the case of fungi and yeast, a hypha or a cell was fixed at the tip of a glass capillary (2-3 pm dia) with slight suction. In the case of nerve cell, cells were spread in a culture dish and stood still for 1 day. After the adhesion of the cells on the bottom of the culture dish, two microelectrodes were set near particular cell(s) from both sides. The distance between the tips of the microelecrodes was 60 40 Opm... 

Adenosine production in the synapse is not through vesicular release in response to nerve firing, as is the case for classical neurotransmitters. Rather, adenosine acts as a local autacoid, the release of which increases upon stress to an organ or tissue. Most cells in culture and in situ produce and release adenosine extracellularly. This... 

Poly-L-lysine-blended chitosan, collagen-blended chitosan and albumin-blended chitosan were also considered, with collagen control material. Culture of PC12 cells and fetal mouse cerebral cortex cells on these biomaterials was used to evaluate their nerve cell affinity. The composite materials, had significantly improved nerve cell affinity compared to chitosan. Poly-L-lysine-blended chitosan exhibited the best nerve cell affinity and was a better material in promoting neurite outgrowth than collagen [328]. 

Animal cell cultures that are initiated from cells removed directly from the animal are called primary cultures (Figure 2). Primary cultures include both explant cultures (i.e., cultures initiated from small pieces of intact tissue), as well as cultures initiated from preparations of individual or dispersed cells (obtained from intact tissue by mechanical or proteolytic dismption). Nerve fiber explant cultures in blood plasma were among the earliest types of tissue cultures (Harrison, 1907). Cells grow out from such tissue explants and form a single layer of cells completely filling the tissue culture vessel surface. Such cell cultures are called confluent monolayers. Confluent monolayers can then be treated with trypsin, so as to remove the individual cells from the culture vessel surface. The resulting cell suspension is then transferred into other culture containers, so that more viable monolayer... 

Research in this area advanced in the 1970 s as several groups reported the isolation of potent toxins from P. brevis cell cultures (2-7). To date, the structures of at least eight active neurotoxins have been elucidated (PbTx-1 through PbTx-8) (8). Early studies of toxic fractions indicated diverse pathophysiological effects in vivo as well as in a number of nerve and muscle tissue preparations (reviewed in 9-11). The site of action of two major brevetoxins, PbTx-2 and PbTx-3, has been shown to be the voltage-sensitive sodium channel (8,12). These compounds bind to a specific receptor site on the channel complex where they cause persistent activation, increased Na flux, and subsequent depolarization of excitable cells at resting... 

Neuron-glial adhesion in nerve cell cultures is mediated by the pi subunit AMOG (adhesion molecule on glia) in the aipi isozyme of Na,K-ATPase [51]. Antibodies to the pi subunit dissociate cell-cell associations and also increase the rate of active... 

Whereas the relationship of solute permeability with lipophilicity has been studied in a large number of in vivo systems (including intestinal absorption models [54,55], blood-brain [56 58] and blood nerve [59] barrier models, and cell culture models [60 62], to name just a few), numerous in vitro model systems have been developed to overcome the complexity of working with biological membranes [63-66]. Apart from oil-water systems that are discussed here, the distribution of a solute between a water phase and liposomes is... 

Figure 20.1 (a) The cell cycle. For details see text, (b) k linear cell cycle. The process need not be cyclical stem cells may proliferate to produce daughter cells that differentiate and daughter cells that enter the Go phase where they remain for some time, indeed some may remain in Go until death (e.g. nerve cells). A stimulus, however, can cause a cell in go to enter the cycle (broken arrow). The numbers in parentheses indicate the time (in hours) that a human liver cell, in culture, takes to complete each phase. 

Similarly, apolipoprotein E expression increases in neurotoxicity mediated by KA (Table 6.3) (Boschert et al., 1999). Apolipoprotein E is a major lipoprotein in the brain. It is involved in the transport, distribution, and other aspects of cholesterol homeostasis. Apolipoprotein E also plays a dominant role in the mobilization and redistribution of brain lipids in repair, growth, and maintenance of nerve cells (Mahley, 1988). The secretion of apolipoproteins E and D may be differentially regulated in cultured astrocytes. In cell culture systems this depends upon the extracellular lipid milieu (Patel et al., 1995). During neurotoxicity mediated by KA, apolipoprotein E levels increase moderately in astrocytes and apolipoprotein E mRNA increases very strongly in clusters of CA1 and CA3 pyramidal neurons. Based on hybridization in situ and immunohistochemical studies, expression of apolipoprotein E in neurons may be a part of a rescue program to counteract neurodegeneration mediated by KA (Boschert et al., 1999). 

Microwells defined in agarose were used to culture nerve cells. The dendrite growth of the nerve cells was studied in narrow tunnel-shaped channels in agarose. The tunnels were fabricated by photo-thermal etching the agarose [863]. 

In 1907, Ross Granville Harrison introduced tissue culture as a new technique for the study of nerve fibre outgrowth [24], At that time, it was hardly envisioned that cell culture would become the most widespread research tool in life sciences and an important method for preparing antibodies, vaccines and drugs. During the development of tissue culture, parameters such as sterility, temperature, gas mixture, medium composition and substrate features were found to be critical for... 

In cultured cortical neurons, by confocal microscopy, Lee and colleagues [54] demonstrated a receptor-mediated internalization of fluores-cently labeled D-Ala-deltorphin and a retrograde transport of the peptide within nerve cell bodies that might be involved in mediating some of the longterm transcriptional effects of opioids. 

VLCFA accumulation has an adverse effect on membrane structure and function. For example, in cultured adrenocortical cells, the addition of C26 0 to the media results in increased microviscosity of the cell membrane and decreased secretion of cortisol after ACTH stimulation. Although similar studies have not been carried out in nerve cells, the effect of VLCFA on neural cell membranes may also result in the neurological manifestations of patients with X-ALD. 

As long as embryonic stem cells in culture are grown under certain conditions, they can remain undifferentiated (unspecialized). But if cells are allowed to clump together to form embryoid bodies they begin to differentiate spontaneously into specific cell types (muscle cells, nerve cells, etc.). To generate cultures of specific types of differentiated cells, various growth factors are used in the culture media [45],... 

Beck, J., Liten, A., Viswanathan, S., Emery, C., and Builder, S. (1996). Direct capture of Nerve Growth Factor from CHO cell culture by EBA. Presentation, Recovery Biol. Prod., 8th, Tucson, AZ. 

Expression is recombinant and in cell culture, and the cells lack the typical aspect of neurons. The transporter appears to be uruformly distributed over the entire ceU surface but not confined to specialized regions as in the case of nerve terminals. 

There is a long-standing myth that ascorbate is required for the hydroxy-lation of tyrosine to dihydroxyphenylalanine (see Figure 13.4) and the similar reactions of phenylalanine and tryptophan hydroxylases. This belief arose as a result of early studies of a nonenzymic reaction to synthesize the hydroxy-lated amino acids for further study. It became established that ascorbate was required for these hydroxylations, and it is stUl common to include it in the incubation buffer. So far from requiring ascorbate, the addition of relatively low concentrations of ascorbate to preparations of tyrosine hydroxylase that has been activated by cAMP-dependent protein kinase results in irreversible loss of activity, although the unactivated form of the enzyme is unaffected by ascorbate (WUgus and Roskoski, 1988). As discussed in Section 10.4.1, these enzymes are biopterin-dependent, and require dUiydrobiopterin reductase and NADPH for activity. There is, however, evidence that, in some nerve cell lines in culture, tyrosine hydroxylase may be induced by ascorbate (Seitz et al., 1998). 

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