Temporal evolution of 3-nitropropionic acid-induced neurodegeneration in the rat brain by T-2-weighted, diffusion-weighted, and perfusion magnetic resonance imaging

An appropriate detecting technique is necessary for the early detection of neurodegenerative diseases. 3-Nitropropionic acid-intoxicated rats serve as the animal model for one neurodegenerative disease, Huntington's disease. Non-invasive diffusion- and T-2-weighted magnetic resonance imaging were ap plied to study temporal evolution and spatial distribution of brain lesions which were produced by intravenous injection of 3-nitropropionic acid in r ats. Lesions in the striatum, hippocampus, and corpus callosum but not in t he cortex were observed 3 and 4.5 h after 3-nitropropionic acid injection ( 30 mg/kg) on the diffusion- and T2-weighted images, respectively (n = 6). T he results demonstrated that the diffusion-weighted imaging is not only sup erior to T-2-weighted imaging in detecting onset of 3-nitropropionic acid-i nduced excitotoxic brain damage but also differentiates lesion and non-lesi on areas with better spatial resolution than T2-weighted imaging. Additiona lly, to correlate structural alterations with pathophysiological conditions , dynamic susceptibility contrast magnetic resonance imaging was performed before and 4 h after 3-nitropropionic acid administration (n = 8). The rela tive cerebral blood volume was significantly elevated in the striatum (P < 0.001) but not in the cortex after 3-nitropropionic acid administration. Th e changes in regional relative cerebral blood volume were well correlated t o the changes in signal intensities in the corresponding areas on the diffu sion- and T2-weighted images. The combined structural and functional information in this study may provid e new insights and therapeutic strategies in treating neurodegenerative dis eases. (C) 1999 IBRO. Published by Elsevier Science Ltd.