Experimental study on spreading cortical depression in cat model using functional MRI
HUANG Jin-bai1, REN Bo-xu1, CHEN Chang-yi1, LEI Hong-wei1, XU Hai-bo2, KONG Xiang-quan2
1. Department of Medical Imaging, Medical College of Yangtze University, Jingzhou Hubei 434000, China; 2. Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
Abstract：To study the brain functional activation of cat model with spreading cortical depression(SCD) induced by KCl stimulation using blood oxygenation level dependent functional magnetic resonance imaging(BOLD-fMRI). Methods: Six adult female cats were anesthetized with ketamine(25mg/kg, i.m.) and chlorpromazine(10mg/kg, i.m.). Craniotomies were performed in both frontal sinuses, which were then filled with agar(2% in sterile saline) to reduce image susceptibility effects between brain and adjacent tissue. A second craniotomy with durectomy 5mm lateral to the midline and 5mm posterior to the bregma exposed the surface of the suprasylvian gyri for KCl/agar and sterile saline/agar application respectively. Images were acquired using a 1.5T super-conducting magnet(Siemens Vision 1.5T). The functional imaging of brain cortex by BOLD technique was obtained in resting phase, KCl stimulated phase and sterile saline stimulated phase respectively. Results: The activated regions included the local areas which contacted KCl of the suprasylvian gyrus and adjacent areas of the marginal gyrus, and spread to posterior part of the marginal gyrus, but there were no activated regions on the opposite hemisphere. The signal of fMRI increased significantly in the local activated areas immediately after the application of KCl and sustained thereafter, showed on time-signal intensity curve. In contrast, the application of sterile saline did not cause the signal of fMRI increase. Conclusion: BOLD-fMRI is reliable in detecting the changes of cerebral blood flow(CBF) associated with SCD and is valuable for evaluating SCD.
2008, Vol. 19 
