DOES LEAD DAMAGE MOTOR-NEURONS

It has been suggested that lead (Pb) may damage motor neurons selectiv ely after retrograde axonal transport from the neuromuscular junction. This has reinforced suspicions that rb could be a cause of some spora dic motor neuron diseases, However, the long-term effect of Pb on spin al motor neurons is not known. To investigate this, we injected mice i n the right hindlimb with 0.1 ml of 2.5% Pb nitrate. Nine months later we measured the sizes and counted the numbers of motor neuron cell. b odies in the anterior horns of the L4; spinal cord, There was no signi ficant difference in sizes or numbers of motor neuron cell bodies betw een the left and right sides of the spinal cord in either group or bet ween groups. These data do not therefore support the hypothesis that P b transported from muscle damages spinal motor neurons. (C) Harcourt B race & Co. Ltd 1998.