Acrylamide effects on the macaque visual system. II. Retinogeniculate morphology.

: Oral acrylamide dosing for 6-10 weeks produced axonal swellings with neurofilament accumulation in the distal optic tract and lateral geniculate nucleus of macaques. No swellings were seen in the retina or optic nerve. Monkeys that were killed 6-8 months after similar dosing showed a marked neuronal degeneration in the visual pathways that was more pronounced after two than after a single period of exposure. This degeneration was characterized by the following: loss of ganglion cells in central retina with relative sparing of other retinal neurons; disproportionate degeneration of temporal to central optic nerve and the dorsal optic tract; and neuronal atrophy in parvocellular layers of the lateral geniculate nucleus, with relative sparing of magnocellular layers. The pattern of neuronal loss suggests that one type of retinal ganglion cell or its axon may be especially vulnerable to damage by acrylamide. The selective neuronal damage produced by acrylamide may help explain the nature of the visual dysfunction associated with this intoxication.