title: Decrease in acetylcholine receptor number correlated with increased naturally occurring trochlear motor neuron death during development.
abstract: It has been observed that daily application of neostigmine onto the chorioallantoic membrane drastically reduced the total number of acetylcholine receptors in the superior oblique muscle of duck embryos. Here the effects of neostigmine on the magnitude of naturally occurring death of trochlear motor neurons during embryonic development were investigated. There was an enhanced loss of neurons in the neostigmine-treated embryos. Neostigmine neither affected the initial production of normal numbers of motor neurons nor had any direct toxic effect on their ultrastructure. The decrease in muscle activity did not always correlate with increased motor neuron survival. There may be a relationship between acetylcholine receptor distribution and naturally occurring neuronal death.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D004372:Ducks / Q000196:embryology*; D004625:Embryo, Nonmammalian / Q000502:physiology; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D009388:Neostigmine / Q000494:pharmacology; D011950:Receptors, Cholinergic / Q000032:analysis*; D014321:Trochlear Nerve / Q000166:cytology / Q000196:embryology* / Q000648:ultrastructure
chemical_list: D011950:Receptors, Cholinergic; D009388:Neostigmine