Calcium signals induced by FGF-2 in parasympathetic neurons: role of second messenger pathways.

Basic Fibroblast Growth Factor, or FGF-2, has been shown to promote neuronal survival and neurite outgrowth in dissociated neurons from the embryonic chick ciliary ganglion; in these effects the three main signal transduction pathways downstream the activated FGFR receptor, i.e. the MAPK, the PI3-K and the PLCγ ones, are differentially involved.

Neuregulin1/ErbB4-induced migration in ST14A striatal progenitors: calcium-dependent mechanisms and modulation by NMDA receptor activation.

Background: A number of studies have separately shown that the neuregulin1 (NRG1)/ErbB4 system and NMDA-type glutamate receptors (NMDARs) are involved in several aspects of neuronal migration. In addition, intracellular calcium fluctuations play central roles in neuronal motility. Stable expression of the tyrosine kinase receptor ErbB4 promotes migratory activity in the neural progenitor cell line ST14A upon NRG1 stimulation.

Interaction of spherical silica nanoparticles with neuronal cells: size-dependent toxicity and perturbation of calcium homeostasis.

The effects of Stöber silica nanoparticles on neuronal survival, proliferation, and on the underlying perturbations in calcium homeostasis are investigated on the well-differentiated neuronal cell line GT1-7. The responses to nanoparticles 50 and 200 nm in diameter are compared. The 50-nm silica affects neuronal survival/proliferation in a dose-dependent way, by stimulating apoptotic processes.

Specificity of the second messenger pathways involved in basic fibroblast growth factor-induced survival and neurite growth in chick ciliary ganglion neurons.

Basic fibroblast growth factor (bFGF) exerts multiple neurotrophic actions on cultured neurons from the ciliary ganglion of chick embryo, among them promotion of neuronal survival and of neurite outgrowth. To understand the specificity of the signal transduction cascades involved in the control of these processes, we used pharmacological inhibitors of the three main effectors known to act downstream of the bFGF receptor (FGFR): phospholipase Cgamma (PLCgamma), mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase (PI3-K). Neuronal survival was assessed at 24 and 48 hr; neurite growth was analyzed both on dissociated neurons and on explants of whole ganglia.

Temporal dynamics of neurite outgrowth promoted by basic fibroblast growth factor in chick ciliary ganglia.

Basic fibroblast growth factor (bFGF) is a potent and multifunctional neurotrophic factor that can influence neuronal survival and differentiation. It has been shown to modulate growth and orientation of neuritic processes both in intact organs and in neuronal cultures, with a wide spectrum of effects on different preparations. Here we report that it promotes neurite growth in developing parasympathetic neurons from the chick ciliary ganglion.

GDNF and bFGF are differentially involved in glial cell differentiation and neurite bundle formation in cultures from chick embryonic ciliary ganglia.

We have shown that the neurotrophic factors glial cell line-derived neurotrophic factor (GDNF) and basic fibroblast growth factor (bFGF) exert different effects on glial cells in cultures from chick embryo ciliary ganglia. bFGF acts as a mitogen on glial cells, and induces their aggregation to neuronal bodies; after 48 h of culture no glial cells could be observed along neurites. GDNF has no proliferative role; in contrast, it promotes the expression of the differentiative marker O4 and the association of glial cell bodies to neurites to form robust bundles.

A K(+) channel activated by cholinergic muscarinic receptors in chick ciliary ganglion neurons at early developmental stage.

Embryonic chick ciliary ganglion (CG) neurons obtained from E7-E8 ganglia maintained in serum-free medium were stimulated with 50 microM muscarine. A fast hyperpolarization of the membrane potential was observed in 25% of the cells tested, that in some cases was associated with a slower depolarization. Accordingly, in voltage clamp experiments, either an outward current or a biphasic current response could be observed.

In vitro analysis of neuron-glial cell interactions during cellular migration.

We used time-lapse microscopy to study the in vitro migration of neuronal cells from developing chick ciliary ganglion. These cells, when dissociated and cultured in a chemically defined medium, are able to migrate and to associate into clusters. We focused our attention on the study of the distribution of neuronal velocity components.