부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.nbd.2005.06.013 Byline: P.F. Fabene (a), R. Weiczner (b), P. Marzola (c), E. Nicolato (a), L. Calderan (a), A. Andrioli (a), E. Farkas (b), Z. Sule (b), A. Mihaly (b), A. Sbarbati (a) Keywords: Convulsions; Epilepsy; Edema; Cerebral cortex; Temporal lobe; Parietal cortex; Hippocampus; Medial thalamus; Histology; Electron microscopy Abstract: Structural and functional MRI was used in conjunction with computerized electron microscopy morphometry to study changes 2 h, 24 h and 3 days after 4-aminopyridine-induced seizures lasting 2 h in rats. T2 (relaxation time) values showed changes throughout the cerebral cortex, hippocampus, amygdala and medial thalamus, with a different temporal progression, showing a complete recovery only after 3 days. Two hours after seizures, the apparent diffusion coefficient was decreased throughout the brain compared to control animals, and a further decrease was evident 24 h after seizures. This was followed by a complete recovery at 3 days post-seizures. Functional MRI was performed using regional cerebral blood volume (rCBV) maps. The rCBV was increased shortly after convulsions (2 h) in all structures investigated, with a significant return to baseline values in the parietal cortex and hippocampus, but not in the medial thalamic nuclei, 24 h after seizure onset. No rCBV alterations were detected 3 days after seizures. Electron microscopy of tissue samples of parietal neocortex and hippocampus revealed prominent astrocytic swelling 2 h post-convulsions which decreased thereafter gradually. In conclusion, this experiment reports for the first time structural and functional brain alterations, lasting several hours, in 4-aminopyridine-treated rats after seizure onset. MRI approach combined with histological and ultrastructural analysis provided a clarification of the mechanisms involved in the brain acute response to ictal activity. Author Affiliation: (a) Section of Anatomy and Histology, Department of Morphological and Biomedical Sciences, Faculty of Medicine, Strada Le Grazie 8, 37134 Verona, Italy (b) Department of Anatomy, Faculty of Medicine, Albert Szent-Gyorgyi Health Science Center, University of Szeged, Hungary (c) Center of Experimental Magnetic Resonance Imaging, University of Verona, Verona, Italy Article History: Received 28 April 2005; Revised 11 June 2005; Accepted 16 June 2005