Basal ganglia degeneration, myelin alterations, and enzyme inhibition induced in mice by the plant toxin 3-nitropropanoic acid.

The plant toxin, 3-nitropropanoic acid, produced topographically and morphologically distinctive lesions in mice after daily intraperitoneal injections. In the lateral caudate-putamen there were bilateral and symmetrical lesions consisting of marked swelling and pyknosis of individual cells and processes in otherwise unaffected tissue. The appearance of transitional forms and the usual post-synaptic location of the swollen processes indicated that affected cells were neurons. A few mice exhibited a more diffuse spongy change in the lateral caudate-putamen that caused major architectural changes. In the globus pallidus, entopeduncular nucleus, and anterior substantia nigra pars reticulata there was fine spongy change of the neuropil that spared cell bodies, and was primarily due to swelling of dendrites. A third lesion pattern in myelinated tracts of the midbrain, medulla, and spinal cord consisted of adaxonal, intramyelinic cleft formation. Succinate dehydrogenase activities assayed in frozen brain sections and in isolated mitochondria were markedly reduced in intoxicated mice.