Skouras Emmanouil, Pavlov Stoyan, Bendella Habib, Angelov Doychin N
Department of Trauma, Hand, Reconstructive Surgery, Universität zu Köln, Köln, Germany.
Adv Anat Embryol Cell Biol. 2013;213:1-105, vii. doi: 10.1007/978-3-642-33311-8_1.
Recovery of mimic function after facial nerve transection is poor: the successful regrowth of axotomized motoneurons to their targets is compromised by (1) poor axonal navigation and excessive collateral branching, (2) abnormal exchange of nerve impulses between adjacent regrowing axons, and (3) insufficient synaptic input to facial motoneurons. As a result, axotomized motoneurons get hyperexcitable and unable to discharge. Since improvement of growth cone navigation and reduction of the ephaptic cross talk between axons turn out be very difficult, we concentrated our efforts on the third detrimental component and proposed that an intensification of the trigeminal input to axotomized electrophysiologically silent facial motoneurons might improve specificity of reinnervation. To test our hypothesis we compared behavioral, electrophysiological, and morphological parameters after single reconstructive surgery on the facial nerve (or its buccal branch) with those obtained after identical facial nerve surgery but combined with direct or indirect stimulation of the ipsilateral infraorbital (ION) nerve. We found that in all cases, trigeminal stimulation was beneficial for the outcome by improving the quality of target reinnervation and recovery of vibrissa! motor performance.
轴突切断的运动神经元向其靶标成功再生受到以下因素的影响：（1）轴突导航不佳和过度的侧支分支；（2）相邻再生轴突之间神经冲动的异常交换；（3）对面部运动神经元的突触输入不足。结果，轴突切断的运动神经元变得过度兴奋且无法放电。由于改善生长锥导航和减少轴突之间的电突触串扰非常困难，我们将精力集中在第三个有害因素上，并提出增强对轴突切断的电生理沉默的面部运动神经元的三叉神经输入可能会提高再支配的特异性。为了验证我们的假设，我们将面神经（或其颊支）单次重建手术后的行为、电生理和形态学参数与相同面神经手术后但联合直接或间接刺激同侧眶下神经（ION）后获得的参数进行了比较。我们发现，在所有情况下，三叉神经刺激通过改善靶标再支配的质量和触须运动性能的恢复，对结果都有益处。
