Reinnervated muscle fiber type-grouping-inevitable?

Reinnervated muscle fiber type-grouping-inevitable?

Muscle fiber-type grouping (‘clumping’) in cross-sections of patient muscle biopsies and the electrophysiological recordings of enlarged motor unit action potentials (MUAPs) are almost universally interpreted as peripheral nerve damage with subsequent reinnervation of denervated muscle fibers [1, 2]. Other electromyographic potentials, including nascent potentials, are indicators of early muscl...

Regeneration of reinnervated rat soleus muscle is accompanied by fiber transition toward a faster phenotype.

The functional recovery of skeletal muscles after peripheral nerve transection and microsurgical repair is generally incomplete. Several reinnervation abnormalities have been described even after nerve reconstruction surgery. Less is known, however, about the regenerative capacity of reinnervated muscles. Previously, we detected remarkable morphological and motor endplate alterations after indu...

Congenital muscle fiber-type disproportion

Congenital muscle fiber-type disproportion is a condition that can be defined only in the muscle biopsy by 2 obligatory criteria of “disproportion”: (1) a massive type I myofiber predominance of 80% or more, and (2) myofibers of type I are uniformly smaller than normal for age by 2 standard deviations or more, but are not necessarily angular or rounded as in myofiber atrophy. Internal sarcolemm...

A quantitative assessment of muscle spindle formation in reinnervated and non-reinnervated grafts of the rat extensor digitorum longus muscle.

Free grafting of the rat extensor digitorum longus muscle disrupts the neurovascular supply and results in degeneration and subsequent regeneration of both muscle and nerve. Reinnervation of one group of grafts was prevented by severing and ligating the sciatic nerve. Thirty days after surgery, the number of muscle spindles in each graft was determined by examination of serial sections at the l...

Human skeletal muscle fibre type grouping and collateral re-innervation.