Trophic effects of skeletal muscle extracts on spinal cord cultures.

A soluble extract of newborn rat muscle was added to cultures of dissociated embryonic spinal cord cells in order to determine the effect on their morphology. The processes per cell ratio, and the length of neurites were all enhanced by the presence of extract in ventral cord cell cultures, but not in dorsal cord cell cultures. It is possible that muscle-derived neurotrophic factors regulate the in vivo phenomenon of neuronal cell death. Interference with neuron-muscle trophic communication, either directly or indirectly, might lead to excessive loss of motor neurons. This mechanism may be important in the pathogenesis of amyotrophic lateral schlerosis.