Cell Survival Characteristics and Choline Acetyltransferase Activity in Motor Neurone‐Enriched Cultures from Chick Embryo Spinal Cord

The effect of muscle extract on cell survival and choline acetyltransferase (ChAT) activity in cultures of enriched cholinergic neurones from 7-day chick embryo spinal cord was examined. When neurones were grown on hydrated collagen gels, considerable cell survival and ChAT activity were obtained even in the absence of tissue extract. These parameters were stimulated twofold in the presence of skeletal muscle extract but not liver or skin extracts. The cholinergic neurotrophic activity was found to be heat- and trypsin-sensitive, nondialysable, and to act in the virtual absence of glial cells. These data are consistent with a retrogradely acting motor neurone trophic activity.