Fluoro-Ruby as a reliable marker for regenerating fiber tracts.

Area of Science:

• Neuroscience
• Regenerative Medicine
• Histology

Background:

• Assessing neural regeneration efficacy requires robust axon visualization techniques.
• Labeling ascending sensory fibers in the dorsal funiculus is challenging compared to descending tracts.
• Existing methods like biotin dextran amine (BDA) are effective for descending tracts but not ideal for ascending fibers.

Purpose of the Study:

• To evaluate Fluoro-Ruby (FR) as a reliable tracer for labeling ascending sensory fibers in the rat spinal cord.
• To demonstrate FR's utility in visualizing axonal regeneration after spinal cord injury and cell transplantation.

Main Methods:

• Application of Fluoro-Ruby (FR), a dextran tetramethylrhodamine tracer, to the transected dorsal funiculus in rats.
• Intra-funicular transplantation of olfactory ensheathing cells post-transection.
• Visualization of labeled ascending fibers using FR's fluorescent properties, resistant to photobleaching.

Main Results:

• FR efficiently labeled ascending fibers in the dorsal columns of the rat spinal cord.
• Regenerating ascending fibers crossing the injury site were successfully visualized and identified.
• FR uptake by damaged fibers facilitated the detection of regeneration.

Conclusions:

• Fluoro-Ruby (FR) is a reliable fluorescent marker for studying ascending regenerated fibers in spinal cord axonal regeneration.
• FR offers advantages including photobleaching resistance and no need for additional tissue processing.
• FR is suitable for both in vivo and in vitro applications in neural regeneration research.