Chapter 5: Methods and protocols in peripheral nerve regeneration experimental research: part II-morphological...

Area of Science:

• Neuroscience
• Microscopy Techniques
• Histology

Background:

• Morphological analysis of peripheral nerve fibers is crucial for understanding neural structure and function.
• Standardized and detailed protocols are needed for reliable light, confocal, and electron microscopy studies.
• Stereological analysis provides quantitative data on nerve fiber morphology.

Purpose of the Study:

• To critically review and detail established procedures for peripheral nerve fiber morphological analysis.
• To emphasize the utility of osmium tetroxide post-fixation across different embedding methods.
• To provide practical guidance on imaging approaches and stereological analysis techniques.

Main Methods:

• Detailed protocols for light, confocal, and electron microscopy of peripheral nerve fibers.
• Emphasis on osmium tetroxide post-fixation as a universal enhancement step.
• Explanation of design-based sampling and the disector for morpho-quantitative stereological analysis.

Main Results:

• Osmium tetroxide post-fixation enhances morphological preservation irrespective of embedding medium.
• Different embedding procedures (paraffin vs. resin) can impact the size distribution of myelinated nerve fibers.
• Practical considerations for various imaging techniques are addressed.

Conclusions:

• Standardized, detailed protocols are essential for accurate peripheral nerve fiber analysis.
• Osmium tetroxide post-fixation is a valuable technique for improving morphological detail.
• Embedding methods can influence quantitative stereological outcomes, necessitating careful selection.