The use of monosodium glutamate in identifying neuronai populations in mice infected with scrapie

The excitatory amino-acid, monosodium glutamate, which causes degeneration in the retinal ganglion cells in neonatal mice, was used to investigate the transport of scrapie within optic nerve axons. In treated mice, there was prolongation of the incubation period following intraocular infection with the ME7 strain of scrapie, and a decrease in the severity of retinopathy after intracerebral infection with the 79A strain. These data confirm that scrapie infection spreads along neural pathways, and demonstrate the potential use of selective neurotoxins to study pathogenesis.