3-NITROPROPIONIC ACID PRODUCES INDIRECT EXCITOTOXIC DAMAGE TO RAT STRIATUM

The mechanism of striatal damage induced by 3-nitropropionic acid (3-N PA) was studied in rats by neuropathological and neurochemical methods . Neuronal shrinkage with astrogliosis was observed in striatum after local injection of 0.5-5 mu mol 3-NPA. Decortications involving dorsal and lateral aspects of frontal cortex or both frontal and parietal co rtices significantly decreased the severity of striatal injuries induc ed by 3-NPA. This result suggests that corticostriatal projections pla y an important role in the development of striatal damage. No signific ant increase of glutamate and aspartate in striatal dialysates was obs erved, which indicated that 3-NPA may affect the postsynaptical sites and make the striatal neurons more vulnerable to endogenous levels of glutamate. Both of these findings suggested that 3-NPA produces indire ct excitotoxic lesion to striatum. An increase of dopamine found in st riatal dialysates may also be related to the occurrence of striatal da mage.