Growth of diseased human muscle in combined cultures with normal mouse embryonic spinal cord.

Normal and diseased human muscle cells have been grown in combined cultures with 12-14 day embryonic mouse spinal cord explants. Nerve endings on myotubes were found by light and scanning electron microscopy, and motor end-plates were identified by a histochemical reaction for acetylcholinesterase. Contracting myotubes, never observed in cultures of human muscle alone, were found in a culture from normal muscle. Histochemical studies demonstrated the presence of strongly and weakly reacting myotubes for both ATPase pH 9.4 and NADH-TR, but could not be related to the development of fibre types. No differences in morphology or histochemical reactions were found between normal and diseased muscle cells in these combined cultures.