Accelerated loss of motor neurons in the brachial lateral motor column in muscular dystrophic chicks

Stewart, Patricia A.; Hayakawa, B.N.; Rathbone, Michel P.

doi:10.1016/0165-3806(84)90312-2

Cited by 4 publications

(1 citation statement)

References 24 publications

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“…However, the extent of motor neuron death can be decreased or increased by removal or enlargement, respectively, of peripheral target tissue (Shorey, 1909;Hamburger, 1934;Hamburger, 1958;Hollyday and Hamburger, 1976). Survival is also impaired by mutations predominantly affecting muscle (Lanser and Fallon, 1984;Stewart et aL, 1984). It has thus been proposed that embryonie motor neurons require muscle-derived trophic factors for survival (for reviews see Berg, 1982;Hamburger and Oppenheim, 1982).…”

Section: Introductionmentioning

confidence: 99%

Muscle-derived factors that support survival and promote fiber outgrowth from embryonic chick spinal motor neurons in culture

Dohrmann

Edgar

Sendtner

et al. 1986

Developmental Biology

156

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The purpose of the experiments reported is to provide an unambiguous demonstration that embryonie skeletal muscle contains factors that act directly on embryonie spinal motor neurons both to support their survival and to stimulate the outgrowth of neurites. Cells of lumbar and brachial ventral spinal cords from 6-day-old chick embryos were separated by centrifugation in a two-step metrizamide gradient, and a motor neuron enriched fraction was obtained. Motor neurons were identified by retrogradely labeling with rhodamine isothiocyanate, and were enriched fourfold in the motor neuron fraction relative to unfractionated cells. In culture, the isolated motor neurons died within 3-4 days unless they were supplemented with embryonie chick skeletal muscle extract. Two functionally distinct entities separable by ammonium sulfate precipitation were responsible for the effects of muscle extracts on motor neurons. The 0-25% ammonium sulfate precipitate contained molecules that alone bad no effect on neuronal survival but when bound to polyornithine-coated culture substrata, stimulated neurite outgrowth and potentiated the survival activity present in muscle. Mostofthis activity was due to a laminin-like molecule being immunoprecipitated with antisera against laminin, and immunoblotting demonstrated the presence of both the A and B chains of laminin. A long-term survival activity resided in the 25-70% ammonium sulfate fraction, and its apparent total and specific activities were strongly dependent on the culture substrate. In contrast to the motor neurons, the cells from the other metrizamide fraction (including neuronal cells) could be kept in culture for a prolonged time without addition of exogenous factor(s).

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