Activity blockade at the neuromuscular junction: effects on spinal cord choline acetyltransferase during and after the period of naturally occurring cell death.

Treatment of developing chick embryos with curare during the period of naturally occurring cell death is known to ameliorate the motoneuron loss which occurs at this time. Such treatment was found likewise to lead to an increase in levels of lumbar spinal cord choline acetyltransferase (ChAT), indicating that the levels of this enzyme may act as a marker for motoneuron number. Treatment after the cell death period also increased lumbar ChAT activity, suggesting that the neurotrophic effects resulting from curare treatment may also include the stimulation of motoneuron cholinergic differentiation.