MODIFIED SIHLER TECHNIQUE FOR STUDYING THE DISTRIBUTION OF INTRAMUSCULAR NERVE BRANCHES IN MAMMALIAN SKELETAL-MUSCLE

Background: A largely forgotten technique initially designed by Sihler for staining nerve tissue has not been fully explored for staining in tramuscular nerve branches in skeletal muscles. Methods: Fresh, long h eads of triceps from locally bred New Zealand white rabbits were used for this study, Immediately after their removal, the muscles with thei r motor nerve branches from the radial nerve were fixed in 10% unneutr alized formalin, followed by maceration and depigmentation in 3% aqueo us potassium hydroxide, decalcification in Sihler's solution I, micro- dissection, staining in Sihler's solution II, destaining in Sihler's s olution I, neutralization in 0.05% Lithium carbonate, and clearance in increasing concentrations of glycerin. Results: A clear three-dimensi onal orientation of the distribution of the intramuscular nerve branch es within the muscle belly was visualized, It was found in all specime ns that the long head of triceps in the rabbit was constantly innervat ed by three main intramuscular nerve branches and each of them supplie d different amounts of muscle fibers with some variation. Conclusion: The Sihler's neural staining technique can be applied to the study of the distribution of intramuscular nerve branches in limb skeletal musc les. Extension of the technique may be utilised in the identification of neuromuscular compartments in skeletal muscles, Such information ma y be usefully applied in free muscle transfer of segments of skeletal muscle. (C) 1997 Wiley-Liss, Inc.