Talk about a mixed blessing. A pair of new studies shows that immune cells known as macrophages can do an injured neuron good, or can impart further harm.
NEURON BULLIES This image from a new study published September 17 in the Journal of Neuroscience shows an axon from a spinal cord neuron struggling to grow. Large, round cells called macrophages latch on to the axon and drive it backward. This is how macrophages probably hinder neuron regeneration in the brain and spinal cord, also known as the central nervous system. Horn, K.P. et al. 2008. Journal of Neuroscience 28(Sept. 17): 9330-9341
As the real estate axiom about location predicts, the outcome partly depends on where the neuron is injured. A neuron that controls motion or feeling starts out in the brain, runs down the spinal cord and eventually connects with muscles, skin or other organs.
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