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

Abstract

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 applied to study temporal evolution and spatial distribution of brain lesions which were produced by intravenous injection of 3-nitropropionic acid in rats. Lesions in the striatum, hippocampus, and corpus callosum but not in the cortex were observed 3 and 4.5 h after 3-nitropropionic acid injection (30 mg/kg) on the diffusion- and T 2-weighted images, respectively ( n=6). The results demonstrated that the diffusion-weighted imaging is not only superior to T 2-weighted imaging in detecting onset of 3-nitropropionic acid-induced excitotoxic brain damage but also differentiates lesion and non-lesion areas with better spatial resolution than T 2-weighted imaging. Additionally, 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 relative cerebral blood volume was significantly elevated in the striatum ( P<0.001) but not in the cortex after 3-nitropropionic acid administration. The changes in regional relative cerebral blood volume were well correlated to the changes in signal intensities in the corresponding areas on the diffusion- and T 2-weighted images. The combined structural and functional information in this study may provide new insights and therapeutic strategies in treating neurodegenerative diseases.