RT Journal Article SR Electronic T1 Influence of nerve on the formation and survival of acetylcholine receptor and cholinesterase patches on embryonic Xenopus muscle cells in culture JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 633 OP 646 DO 10.1523/JNEUROSCI.02-05-00633.1982 VO 2 IS 5 A1 F Moody-Corbett A1 MW Cohen YR 1982 UL http://www.jneurosci.org/content/2/5/633.abstract AB Embryonic Xenopus muscle cells grown in culture develop discrete patches of high acetylcholine receptor (AChR) density. By following identified muscle cells after staining with fluorescent alpha- bungarotoxin, we have found that many of these AChR patches survive in a fixed position for several days. For AChR patches on the lower surface of the cell (the surface apposed to the culture dish), more than 60% of those which were followed beginning on day 2 survived for a further 4 days. The survival rate was greater when patches were followed from day 3 or later and was almost as high for AChR patches on the upper surface. New AChR patches also formed on all of the muscle cells. When muscle cells were cultured together with spinal cord cells, nerve-muscle contacts developed with a characteristic localization of AChRs along the path of contact. AChR patches did not form elsewhere on these contacted cells. Nerve-contacted muscle cells examined 2 to 3 days after adding spinal cord cells to established (2- to 5-day-old) muscle cultures also exhibited a marked reduction of AChR patches away from the site of contact. This reduction was not due to the nerve having contacted pre-existing AChR patches. Rather, the findings indicate that contact by an appropriate nerve inhibits the formation of AChR patches elsewhere on the contracted muscle cells and reduces the survival of pre-existing AChR patches. Nerve contact also inhibited the formation of cholinesterase (ChE) patches remote from the site of contact and appeared to cause some reduction in the survival of pre- existing ChE patches. Spontaneous twitching was not observed in these experiments, thereby indicating that the remote effects of nerve contact were not mediated by muscle action potentials or contraction. Such remote influences of the nerve may play a role in determining the pattern of innervation on individual muscle cells.