Journal of Neuroscience, Vol 2, 1299-1306, Copyright © 1982 by Society for Neuroscience
Blockade of retrograde axonal transport delays the onset of metabolic and morphologic changes induced by axotomy
PA Singer, S Mehler and HL Fernandez
Axotomy-induced increase in 2-deoxyglucose (2-DG) uptake by motor nuclei
and neuronal chromatolytic changes were studied after subepineural
injection of colchicine into the motor nerve. Hypoglossal nuclei of either
cats or rats were axotomized bilaterally, while one of the nerves was
injected with colchicine or saline proximal to the site of nerve
transection and the other was left intact or injected with saline.
Colchicine abolished or decreased the uptake of 2-DG by axotomized nuclei
and delayed the onset of chromatolysis. The decrease in 2-DG uptake was
observed in rat hypoglossal nuclei between 24 and 48 hr but not 5 days
after drug treatment. In turn, a delay in the onset of chromatolysis was
observed in cat hypoglossal nuclei at 14 days but not 30 days after
treatment. Saline did not prevent chromatolysis nor the increased uptake of
2-DG. Colchicine injected intraneurally in intact preparations did not
result in chromatolysis or in increased 2- DG uptake. Following colchicine
injection, the drug remained localized near the site of injection and
blocked retrograde axonal transport of horseradish peroxidase in the
hypoglossal nerve. These findings suggest that the onset of chromatolysis
and of the increase in 2-DG uptake after axotomy are partly dependent upon
retrograde axonal transport.