Anesth Pain Med.  2016 Apr;11(2):149-154. 10.17085/apm.2016.11.2.149.

The effect of nerve preservation methods on rat sciatic nerve structures studied with Synchrotron small-angle X-ray scattering (SAXS)

• Byun SH
• Lee SM
• Han SM
• Ryu T
• Jung JY
• Kim BI

• KMID: 2358476
• DOI: http://doi.org/10.17085/apm.2016.11.2.149

Abstract

BACKGROUND
Synchrotron small-angle X-ray scattering (SAXS) is a very useful technique for experimental study of the nano-structure of the nervous system of animals. The study was designed to evaluate nerve preservation methods for the measurement of SAXS patterns.
METHODS
Normal sciatic nerves extracted from male Sprague- Dawley rats were preserved in saline (N = 2), formalin (N = 2) or liquid nitrogen (N = 2) for 1 day, followed by measurement of SAXS patterns. SAXS patterns of normal sciatic nerves (N = 3) extracted just before the initiation of the experiment were used as controls. The study was carried out using the 4C1 beamline at Pohang Accelerator Laboratory in Korea. Incoming X-rays were monochromatized at 11 keV using a double multilayer (WB4C) monochromator with beam size of approximately 0.5 (V) × 0.8 (H) mm2. The exposure time was set at 60 sec, and 8 to 12 images per sample were acquired at a 0.5 mm interval.
RESULTS
The periodic peaks of interfibrillar space between collagen fibrils were undetectable. The periodic peaks of the myelin sheath and collagen fibers were weakly detected or undetected in the nerves preserved in normal saline or formalin. The periodic peaks and intensity of the myelin sheath, collagen fibers, and interfibrillar space between collagens in the nerves preserved in liquid nitrogen were comparable to those of nerves in the ex vivo state.
CONCLUSIONS
The study results indicated that preservation of nerves in liquid nitrogen is adequate for measurements with SAXS. However, saline and formalin preservation techniques were inadequate for SAXS measurement.

Keyword

Sciatic nerve preservation; Small angle X-ray scattering

MeSH Terms

Animals
Collagen
Formaldehyde
Gyeongsangbuk-do
Humans
Korea
Male
Methods*
Myelin Sheath
Nervous System
Nitrogen
Rats*
Sciatic Nerve*
Synchrotrons*
Collagen
Formaldehyde
Nitrogen

Figure

• 

  Fig. 1 One dimensional SAXS plot of nerve in ex vivo state (normal) and nerve preserved for one day in formalin, normal saline and liquid nitrogen (LN2) measured by using of SAXS at horizontal direction. Myelin sheath was measured as 18 nm periodicity peak patterns (M1st, M2nd, M3rd,) in ex vivo state (A). Interfibrillar distance was between collagen fibrils measured 66 nm periodicity peak patterns (F1st, F2nd) which is wide and weak in ex vivo state (A). Periodic peaks, F1st and F2nd, of nerve preserved in formalin and saline were not measured (B, C). The Measured periodic peaks and intensity, M1, M2 and M3, of nerve preserved in formalin and saline were weak and/or not detected. Periodic peaks and intensity, F1st, F2nd and M1, M2, M3, of nerve preserved in liquid nitrogen, were comparable to those of nerve in ex vivo state (D).

• 

  Fig. 2 One dimensional SAXS plot of nerve in ex vivo state (normal) and nerve preserved for one day in formalin, saline and liquid nitrogen (LN2) measured by using of SAXS at vertical direction. Collagen fiber was measured as 67 nm periodicity peak pattern (C1st–C9th) in ex vivo state (A). Periodic peaks, C1st–C9th, of the nerve preserved in formalin and saline were not measured and/or weak intensity (B, C). Periodic peaks and intensity, C1st–C9th, of the nerve preserved in liquid nitrogen were comparable to those of nerve in ex vivo state (D).

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