Reversible dissociation of a bovine cardiac factor that supports survival of avian ciliary ganglionic neurones

Schwann cells support and facilitate axonal growth during development and successful regeneration in the peripheral nerve. In the regenerating rat sciatic nerve, Schwann cells provide a trophic milieu for primary sensory, sympathetic, and motoneurons. We have characterized a neurotrophic activity produced by adult rat sciatic nerve Schwann cells and a spontaneously immortal Schwann cell clone (iSC). This activity elicits neurite outgrowth from chick embryo explants of both CNS and PNS. The iSC activity has been concentrated by cation-exchange chromatography and compared to known neurotrophins in bioassay. Pooled bound fractions elicit neurite outgrowth from sympathetic, ciliary and motoneurons. In collagen matrix cocultures of iSC and E4 ventral horn (before motor axon extension to muscle targets), the iSC activity can direct the initial axonal extension from motoneurons. The data presented suggest that Schwann cell-produced activity may mediate motoneuron axonal extension before contact with their peripheral source of neurotrophin.

Section: Materials and Methods Bioassaymentioning

confidence: 99%

Characterization of a Schwann cell neurite‐promoting activity that directs motoneuron axon outgrowth

Bolin

Shooter

1994

“…Ciliary ganglia were removed from embryonic day 8 chicken embryos and dissociated as previously described (Bonyhady et al, 1982(Bonyhady et al, , 1985. Briefly, ganglia were incubated in Ca2+/Mg2 + -free Hanks' solution containing trypsin (0.8 mg/ml) for 20 min at 37"C, then washed 3 times with DMEM/10% horse serum, and finally resuspended in DMEM/lO% horse serum.…”

Section: Dissociation and Culture Of Chick Ciliary Neuronsmentioning

confidence: 99%

Co‐activation of insulin‐like growth factor‐I receptors and protein kinase C results in parasympathetic neuronal survival

Crouch

Hendry

1991

We have studied the interaction between several growth factors to promote parasympathetic neuronal survival. Neither insulin nor insulin-like growth factor-I (IGF-I) had any effect on the survival of embryonic day 8 chick ciliary neurons in culture. Similarly, the protein kinase C activator phorbol dibutyrate (PdBu) had only a minor survival-promoting activity. In combination with PdBu, however, IGF-I or insulin, at concentrations sufficient to act through the IGF-I receptor, were highly synergistic. In a similar fashion, acidic fibroblast growth factor (aFGF)-induced neuronal survival was greatly enhanced by PdBu, as well as by insulin or IGF-I. When added alone, aFGF-induced cell survival required the presence of 1% serum. However, addition of aFGF, IGF-I, or insulin with PdBu under serum-free conditions replaced the serum requirement. That is, these agonist combinations could apparently induce the second messenger requirement for ciliary neuronal survival. Therefore, IGF-I must now be included in the list of candidate molecules responsible for directing parasympathetic nerve formation. The synergy between agonists observed in these experiments highlights the possibility that combinations of growth factors, rather than sole molecules, may dictate parasympathetic nervous system development in vivo.

“…Neurotrophic activity was assayed with neurones dissociated from ciliary ganglia of 8-day-old chick embryos as previously described (Bonyhady et al, 1982). Fourfold dilutions of samples to be assayed were set up in 96-well plates, and approximately 2,200 dissociated neurones were added to each well.…”

Section: Bioassay Of Ciliary Neurotrophic Activitymentioning

confidence: 99%

Monoclonal antibody that inhibits biological activity of a mammalian ciliary neurotrophic factor

Watters

Belford

Hill

et al. 1989

Four monoclonal antibodies to a purified ciliary neurotrophic factor have been produced by a combination of in vivo and in vitro immunization of mouse lymphocytes. Three of the antibodies--3D12, an 1gA subtype, and 5G9 and 2B11, both IgM subtypes--bound to the single band on immunoblots of the purified factor. Of the four clones only one, 3D12, produced antibodies able to inhibit the biological activity of the neurotrophic factor in promoting the survival of ciliary neurones in dissociated culture.