Effective reinnervation of the quadriceps femoris by spinal ventral root cross-anastomosis in rats

Abstract

PURPOSE:To study the effective recovery of the quadriceps femoris by spinal ventral root cross-anastomosis in rats. METHODS: End-to-end anastomosis was performed between the left L 1 and L 3 ventral roots using autogenous nerve graft ,and the right L 1 and L 3 roots were left intact. In control animals, the left L 3 ventral root was cut and shortened, and anastomosis was not performed. Six months postoperatively, the movement of low extremities was detected by electrophysiological examination, hindlimb locomotion and basso, beattie and bresnahan (BBB) scoring at one, three, seven, 14, 21 and 28 days after SCI. Fluorescence retrograde tracing with TRUE BLUE (TB) and HE staining were performed to observe the nerve regeneration. RESULTS: Six months after surgery, the anastomotic nerve was smooth and not atrophic. The amplitudes of action potential were 7.63±1.86 mV and 6.0±1.92 mV respectively before and after the spinal cord hemisection. The contraction of left quadriceps femoris was induced by a single stimulation of the anastomotic nerve. The locomotion of left hindlimb was partially restored after spinal cord hemisection while creeping and climbing. In addition, there was significant difference in the BBB score at one, three and seven days after SCI. TB retrograde tracing and neurophysiologic observation indicated efficient reinnervation of the quadriceps femoris. CONCLUSION: The cross-anastomosis between spinal ventral root can partially reconstruct the function of quadriceps femoris following SCI and may have clinical implication for the treatment of human SCI. Key words: Reinnervation. Quadriceps Muscle. Spinal Nerve Roots. Rats. RESUMO OBJETIVO:Investigar a recuperação efetiva do músculo quadríceps femoral pela anastomose cruzada via raiz espinhal ventral em ratos. MÉTODOS: Anastomose término-terminal foi realizada entre as raízes ventrais L 1 e L 3 à esquerda usando enxerto autógeno de nervo e, à direita, as raízes L 1 e L 3 foram mantidas intactas. Nos animais controles, à esquerda, a raiz ventral de L 3 foi cortada e encurtada sem realização de anastomose. Após seis meses, o movimento das extremidades posteriores foi estudado por exame eletrofisiológico, e pelo escore de basso, beattie e bresnahan (BBB) com um, três, sete, 14, 21 e 28 dias após SCI. Fluorescência retrograde feita com TRUE BLUE (TB) e coloração com HE foram realizadas para observar a regeneração do nervo. RESULTADOS: Seis meses após a cirurgia, a anastomose do nervo estava lisa e sem atrofia. As amplitudes dos potenciais de ação foram 7,63±1,86 mV e 6,0±1,92 mV respectivamente antes e após a hemisecção da medula espinhal. A contração do músculo quadríceps femoral foi induzida por um único estímulo do nervo anastomosado. A locomoção do membro posterior esquerdo foi parcialmente restaurada após hemisecção da medula espinhal ao rastejar e escalar. Ademais, houve diferença significante no escore BBB nos dias um, três e sete após SCI. O traçado da TB retrógrada e a observação neurofisiológica indicaram reinervação eficiente do quadríc...

Functional and Neuromuscular Changes after Anterior Cruciate Ligament Rupture in Rats

“…The last part of the surgical procedure was devoted to expose the L3 dorsal root including quadriceps afferent fibers (31) to evoke and record the motor reflex and the afferent firing rate, respectively. For that, a laminectomy was performed from L1 to L4 to expose dorsal and ventral roots.…”