Structural analysis of a ligatured rat sciatic nerve in the ex vivo state using synchrotron small-angle X-ray scattering (SAXS) |
Bong Il Kim, Ho In Na, Sung Hye Byun, Tae Joo Shin, Taeha Ryu, Jin Yong Jung |
1Department of Anesthesiology and Pain Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea. bikim@cu.ac.kr 2Department of Anesthesiology and Pain Medicine, Kyungpook National University Hospital, Daegu, Korea. 3Pohang Accelerator Laboratory, Pohang, Korea. |
Received: 10 April 2015 • Revised: 22 June 2015 • Accepted: 17 July 2015 |
Abstract |
BACKGROUND To understand the fundamentals of neural tissue injury, experiments on the nano-structured nerve system of animals are essential. This study was designed to reveal the nanostructure changes of an isolated ligatured rat sciatic nerve using the synchrotron small-angle X-ray scattering (SAXS) technique. METHODS Male Sprague-Dawley rats (weighing approximately 250 grams) were used in this study. The SAXS patterns of 1 week after ligatured nerves (N = 5) and the normal sciatic nerves (N = 5) for the control were acquired after extracted approximately 15 mm before the experiment. Experiments were conducted at the 4C1 beam line at the Pohang Accelerator Laboratory in Korea. The exposure time was 60 sec, and 8 to 12 images per sample were acquired in 0.5 mm intervals, including the regions above, around and below the ligatured position. RESULTS The periodic peaks of the myelin sheath and the interfibrillar space of collagen completely disappeared at the ligatured position. Farther from the ligatured point, weak and quite different SAXS patterns were observed for the myelin sheath and interfibrillar space. However, the collagen fiber peaks appeared at all positions, although they were weaker near the ligatured position. CONCLUSIONS The ligature treatment totally destroyed the myelin sheath and interfibrillar space of collagen. In addition, retrograde degeneration developed 2 mm above the ligatured site. The myelin sheath and interfibrillar space of collagen were damaged 6 mm below the ligatured site. However, the collagen fiber structure was not significantly affected by the ligature, indicating a much different structural organization. |
Key Words:
Myelin sheath, Nanostructure, Sciatic nerve ligation, Small angle X-ray scattering |
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