Blockade of rapid axonal transport. Effect of intraocular pressure elevation in primate optic nerve
H. A. Quigley, J. Guy and D. R. Anderson
After acute intraocular pressure (IOP) elevation, an induced disturbance of
rapid axonal transport at the optic nerve head began within three hours at
the IOP levels tested. The accumulation of radioactive label at the scleral
lamina cribrosa increased with time of IOP elevation. There was a 60%
decrease in the amount of transported material in the optic nerve, tract,
and lateral geniculate body (LGN). Detailed analysis suggests that this
decrease is not due to a simple slowdown of transport, but results from a
total block of rapid transport in some axons, with no impairment in other
axons. This total blockade of rapid transport by elevated IOP in involved
axons differs from the apparent slowdown of transport in experimental
papilledema, and the difference may explain the response of ganglion cells
to the two conditions.
