Neuroscience 2005 Abstract
| Presentation Number: | 702.5 |
|---|---|
| Abstract Title: | Chronological changes of photothrombotic ischemia model: MRI and histological analysis. |
| Authors: |
Moon, S.*1
; Kim, H.2
; Shin, Y.1
; Oh, G.1
; Lee, M.3
; Yoon, K.1
1Stroke Research Group, Wonkwang Univ., Iksan-city, Democratic People's Republic of Korea 2South Korea, 344-2, sinryong-dong, 570-180, 3Neurosurgery, 344-2, sinryong-dong, 570-180, |
| Primary Theme and Topics |
Disorders of the Nervous System - Ischemia -- Human studies and animal models |
| Session: |
702. Hypoxia/Ischemia: Animal Models II Slide |
| Presentation Time: | Tuesday, November 15, 2005 2:00 PM-2:15 PM |
| Location: | Washington Convention Center - Room 150B |
| Keywords: | Ischemia, Pathology, MRI |
Ischemic brain injury develops from a complex sequence of pathological events that evolve over time. Authors tried to assess the changes and progress of ischemia in photothrombotic ischemia model using MRI and histological analysis and to provide the information regarding the timing and effect of therapeutic intervention researches.
Photothrombotic ischemia was induced in the motor cortex of Sprague-Dawley male rat using Rose Bengal dye (20mg/kg) and cold light. MRIs including T1-weighted(T1W), T2- weighted (T2W), Diffusion-weighted imaging (DWI), were obtained using 1.5T MRI and 47mm surface coil at 1, 6, 12, 24 hours, 3, 7, 14, 21. 28, 42, and 56 days. After MRI, rats were sacrificed, and the brain sections were stained with H & E, Nissl, Synaptophysin, and Neurofilament. Infarction volume and contrast-noncontrast ratio (CNR) were measured in all images.
Infarction volume was measured the greatest (109mm©ø) on day 1, decreased progressively and reached 8.9mm©ø in 8 weeks. CNR was greatest on 12 hours in DWI and decreased over time. On the contrary, T1W and T2W images showed the constant CNR from the beginning through 8 weeks. Histological analysis showed ischemic changes from 1 hour after lesioning. However, neuronal swelling was more marked in 24 hours. Macrophage infiltration which was shown as marginal hyperdense ring on MRI, began to appear from on day 2 or 3 and persisted up to 4 weeks. Axonal sprouting was marked in the border between 1 and 2 weeks. Infarct area was progressively replaced by gliotic tissues from the periphery, finally leaving the necrotic cyst in the central area.
Photothrombotic ischemia model demonstrated sequential pathological changes over time. MRI alone does not explain the pathological processing of ischemia. Therefore, appropriate selection of timing should be considered depending on the purpose of experiment.
Photothrombotic ischemia was induced in the motor cortex of Sprague-Dawley male rat using Rose Bengal dye (20mg/kg) and cold light. MRIs including T1-weighted(T1W), T2- weighted (T2W), Diffusion-weighted imaging (DWI), were obtained using 1.5T MRI and 47mm surface coil at 1, 6, 12, 24 hours, 3, 7, 14, 21. 28, 42, and 56 days. After MRI, rats were sacrificed, and the brain sections were stained with H & E, Nissl, Synaptophysin, and Neurofilament. Infarction volume and contrast-noncontrast ratio (CNR) were measured in all images.
Infarction volume was measured the greatest (109mm©ø) on day 1, decreased progressively and reached 8.9mm©ø in 8 weeks. CNR was greatest on 12 hours in DWI and decreased over time. On the contrary, T1W and T2W images showed the constant CNR from the beginning through 8 weeks. Histological analysis showed ischemic changes from 1 hour after lesioning. However, neuronal swelling was more marked in 24 hours. Macrophage infiltration which was shown as marginal hyperdense ring on MRI, began to appear from on day 2 or 3 and persisted up to 4 weeks. Axonal sprouting was marked in the border between 1 and 2 weeks. Infarct area was progressively replaced by gliotic tissues from the periphery, finally leaving the necrotic cyst in the central area.
Photothrombotic ischemia model demonstrated sequential pathological changes over time. MRI alone does not explain the pathological processing of ischemia. Therefore, appropriate selection of timing should be considered depending on the purpose of experiment.
Supported by The Ministry of Science & Technology(M2-0415-01-0001) Korea
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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