突触可塑性与面神经损伤后中枢神经功能重组

面神经是周围神经系统最易受损的神经之一.周围神经损伤后,受伤轴突再生或者邻近未受损轴突发出侧支支配相应靶器官以代偿部分功能.但由于受到空间限制,侧支支配有很大局限性.而且有学者发现神经再生支配靶器官与功能恢复虽然关系密切,但并不是完全一致,损伤神经相应的靶器官只要有20%～30%神经纤维再支配,即可实现大部分功能的恢复.     

面神经损伤后星形胶质细胞塑形活动的实验研究

目的 研究面神经损伤修复过程中面神经核内胶质塑形活动的变化。方法 大鼠面神经断伤吻合后1、7、21、60天时,观察面部运动情况,同时用神经逆行示踪结合免疫荧光组织化学的双重标记技术以及透射电镜技术,观察外周损伤后面神经核内胶质原纤维酸性蛋白（glial fibrillary acidic protein,GFAP）表达以及星形胶质细胞超微结构的塑形变化。结果 面神经再生修复后面部运动功能逐渐恢复,但难以完全恢复正常,且常伴有联带后遗症。荧光金逆行示踪标记出面神经核内面运动神经元有严格的躯体定位分布特征。正常状态下面神经核内GFAP表达强度极弱,术后7天时患侧表达强度显著增强,至再生修复晚期减弱,但仍高于健侧水平。超微结构观察显示,术后50天时塑形活化的星形胶质细胞形成板层状突起包裹隔绝面运动神经元。结论 本研究观察了外周损伤后面运动神经元周围星形胶质细胞塑形活动的一些规律性变化,其晚期塑形活动很可能与联带等后遗症的产生机制关系密切。     

面神经损伤后糖皮质激素受体α在面神经核及外周淋巴组织的表达

目的探讨面神经损伤后,糖皮质激素受体α(GRα)在面神经核团及外周淋巴组织的表达和变化规律。方法建立新西兰兔面神经损伤模型,分别于损伤后24?h、48?h、72?h、 7?d、14?d取出面神经核团和颈部淋巴结,采用免疫组化SP法,观察糖皮质激素受体的表达情况。结果糖皮质激素受体α在面神经核团及外周淋巴细胞中均有表达;糖皮质激素受体α表达增高在面神经核中出现在损伤48?h后,颈部淋巴结出现在损伤72?h后。结论糖皮质激素受体α表达在面神经核团及外周淋巴细胞胞核及胞质中,在面神经受到损伤后其表达量增高,而且神经损伤较单纯外伤可以引起较长时间的局部炎症反应。     

豚鼠面神经损伤后面神经核中降钙素基因相关肽的变化

目的:探讨降钙素基因相关肽(CGRP)在面神经损伤再生过程中的作用.方法:采用免疫组化及图像分析技术,观察豚鼠面神经核中的CGRP在面神经损伤后含量和分布的变化.结果:CGRP分布于正常豚鼠面神经核各亚核.面神经损伤后1 d,损伤侧面神经核运动神经元中CGRP阳性反应增强,图像分析CGRP灰度值与对照侧比较,差异非常显著(P＜0.01);损伤后7 d达最高峰(P＜0.001),其后渐降.在损伤后14～35 d,发现显著的束状CGRP阳性纤维从面神经核腹侧向外周延伸.结论:面神经损伤后,面神经核中的CGRP含量和分布出现显著变化,提示CGRP在面神经修复再生过程中起着调控作用.     

大鼠面神经压榨对面神经元CNTF表达的影响

目的 观察将大鼠面神经压榨后面部行为学变化,探索简易稳定的面神经压榨建模方法;检测压榨侧面神经运动神经元中睫状神经营养因子(CNTF)的表达变化。方法 选取健康大鼠30只,解剖右侧面神经主干,蚊式血管钳单齿钳夹,持续1min,设左侧为对照。术后1 、7、14 、21、35d,观察大鼠面部行为学改变;HE染色观察面神经运动神经元的病理形态学变化并进行细胞计数;免疫组化观察面神经元CNTF蛋白的表达并进行光密度分析。结果 面神经压榨损伤后即刻出现同侧面神经瘫痪,术后7～14d达高峰,而后逐渐恢复,35d大鼠面部对称,面瘫完全恢复。HE染色发现术后7、14、21d损伤侧面神经运动神经元数目较对照组减少 (P＜0.01),细胞结构形态紊乱,细胞内空泡增多,核仁偏移。免疫组化发现术后7、14、21d面神经运动神经元CNTF蛋白表达量明显增多(P＜0.01)。结论 神经压榨是建立可逆性面神经麻痹动物模型简易稳定的方法。面神经压榨损伤后,面神经运动神经元内CNTF蛋白的表达增多。     

面神经损伤后穴位电针刺激对面神经核中几种神经营养因子mRNA表达的影响

目的：观察穴位电针刺激对面神经再生过程中神经核组织神经营养因子（NTFs，包括神经生长因子NGF、脑源性神经营养因子BDNF、神经营养因子3NT－3）表达的影响。方法：日本大耳白兔面神经压榨伤后，电针刺激翳风、颧Liao、地仓、颊车、四白、阳白、合谷穴，每天30分钟，2周为一疗程。分别于一、二、三疗程治疗后，应用原位杂交技术检测面神经核组织中上述三种神经营养因子mRNA表达水平的变化。结果：两组动物的面神经核组织中NGF、BDNF、NT－3mRNA表达高峰均在神经损伤后第6周；第二、第三疗程结束后，针刺组NGF、BDNF及NT－3mRNA的杂交信号均明显强于对照组。结论：在面神经再生过程中，穴位电针刺激能明显增强面神经核组织中NGF、BDNF及NT－3的表达，进而促进面神经再生。     

豚鼠面神经损伤后面神经核中降钙素基因相关肽的变化

目的:探讨降钙素基因相关肽(CGRP)在面神经损伤再生过程中的作用.方法:采用免疫组化及图像分析技术,观察豚鼠面神经核中的CGRP在面神经损伤后含量和分布的变化.结果:CGRP分布于正常豚鼠面神经核各亚核.面神经损伤后1 d,损伤侧面神经核运动神经元中CGRP阳性反应增强,图像分析CGRP灰度值与对照侧比较,差异非常显著(P＜0.01);损伤后7 d达最高峰(P＜0.001),其后渐降.在损伤后14～35 d,发现显著的束状CGRP阳性纤维从面神经核腹侧向外周延伸.结论:面神经损伤后,面神经核中的CGRP含量和分布出现显著变化,提示CGRP在面神经修复再生过程中起着调控作用.     

Unilateral facial nerve paralysis after electrocution injury

We present a case of acute, unilateral facial nerve paralysis in a patient who had received a low voltage electrical current. This is an extremely rare cause of this neurological condition. The patient regained complete neurological function approximately three months after the incident. Unilateral facial nerve paralysis most commonly occurs due to infection or blunt or penetrating trauma; it has not been previously reported as a result of low voltage electrical injury.     

Rabbit facial nerve regeneration in autologous nerve grafts after antecedent injury

OBJECTIVE: The effect of incomplete antecedent injuries on subsequent facial nerve regeneration within cable graft repairs is not known. The purpose of this study is to compare facial nerve regeneration after an immediate and delayed neural cable graft repair. METHOD: Rabbit facial nerve regeneration after complete transectional injuries of the buccal division was compared in two experimental models. In one, a 10-mm segment of the nerve was transected, rotated 180 degrees, and immediately repaired as a cable graft (N=8). In the second, a preliminary nerve crush was allowed to recover over a 4-week period and a 10-mm segment of nerve centered on the crush site was then transected, rotated 180 degrees, and delay repaired as a cable graft (N = 7). Data are presented as total numbers of regenerating myelinated axons that traverse the surgical repair to innervate the cable graft and distal nerve stumps, as well as the percentage of regenerating neurites compared with preoperative pooled and individual controls. Subpopulations of regenerating neurons are delineated to quantify the pattern of neural innervation. RESULTS: Five weeks after cable graft repair both groups had similar myelinated outgrowth from the proximal nerve stump across the proximal anastomosis to innervate the cable graft (3995 +/- 1209 vs. 3284 +/- 651; P = .89). However, the delayed repair group had more intrafascicular regeneration within cable grafts (2261 +/- 931 vs. 1660 +/- 1169; P = .02) and distal nerve stump (1532 +/- 281 vs. 445 +/- 120; P = .004) than the immediate repair group. The immediate repair group had greater extrafascicular nerve regeneration in the cable graft (2335 +/- 1954 vs. 437 +/- 236; P = .001) and more myelin and axonal debris in pre-existing neural fascicles of the cable graft (P = .02) and distal nerve stump (463 +/- 187 vs. 103 +/- 87; P = .02). CONCLUSIONS: Antecedent priming lesions do not enhance axonal survival as determined by regenerating myelinated axonal counts. However, antecedent injuries enhance the efficiency of neural innervation of the affected mimetic musculature by increasing the number of myelinated intrafascicular neural regenerants in the cable graft and distal nerve stump. This is accomplished by two factors: increased perineural fibrosis and decreased intrafascicular myelin and axonal debris.     

颞骨骨折性面瘫手术减压时机的实验研究

目的制作颞骨骨折性面瘫的动物模型,初步探讨大鼠面瘫的自然发展过程,了解不同手术减压时机面瘫的治疗效果及减压后面瘫的恢复变化过程。方法选用Wistar大鼠32只,制作颞骨骨折性面瘫动物模型。将完全面瘫的大鼠随机分成4组:对照组即不减压组,2周减压组,4周减压组,8周减压组。分别于以上不同的时间行面神经减压术,并于不同时间测定面神经刺激阈值,以观察面神经的恢复情况。结果对完全面瘫的大鼠于面瘫后1周行面神经阈值检查,对最大电流刺激(3mA)无反应。4组大鼠面神经刺激阈值的恢复速度相比,2周、4周减压组比不减压组及8周减压组快;2周减压组面神经的恢复速度比4周减压组快。结论通过血管钳钳夹大鼠的面神经骨管,可以造成颞骨骨折性面瘫的大鼠模型。面神经减压术在面神经受损后4周内进行,可缩短其面神经阈值的恢复时间;且减压时间越早,面神经的恢复速度越快。     

实验性面神经损伤后的神经再生速度

目的研究实验性面神经损伤后的再生速度。方法在立体定位下,面神经核团内注射标记蛋白前体结合闪烁计数技术研究豚鼠面神经损伤后的神经再生速度。结果用快、慢轴浆转运测出的外周面神经平均再生速度分别为2.84±0.12mm/d与3.16±0.08mm/d,再生延隔时间分别为2.67±0.11d与1.40±0.07d。结论研究得到豚鼠外周面神经损伤后的神经再生速度。     

Rehabilitation of the face following traumatic injury to the facial nerve

Etiology, diagnosis, and surgical management of facial paralysis due to traumatic injury of the VIIth cranial nerve are discussed. Sixty patients are reviewed who underwent some type of surgical procedure for the repair of the facial nerve. These cases are categorized according to etiology, which includes temporal bone fractures, iatrogenic injuries, and penetrating wounds of the head and neck. The results of a poll of eight leading otologists on their approaches to several aspects of the surgical management of these injuries are presented in the Discussion section. The diagnostic and prognostic studies associated with facial paralysis, as well as the more common surgical procedures available for repair of the facial nerve, are briefly reviewed.     

Expression of aquaporin 2 following facial nerve crush in rats

Conclusion: We demonstrated an early increase in aquaporin 2 (AQP2) expression in a motor nerve (extratemporal facial nerve, FN) following acute peripheral compression (crush), concomitant to effective development of motor dysfunction (facial palsy). The early increase in AQP2 expression that occurred concomitantly with the appearance of a deficit in a peripheral motor nerve suggests that this protein is involved in the physiological events associated with post-injury edema, similar to the already demonstrated behavior of AQP4 in the central nervous system (CNS). Objective: The aim of this study was to assess the expression of AQP2 in the FN of rats up to 7 days after crush. Methods: The extratemporal trunk of the right FN of rats was subjected to mechanical crush, and the expression of AQP2 in the affected (right) and non-affected (left) FN was measured by means of western blotting at days 1, 3, and 7 after injury. Behavioral analysis of the development of facial palsy was also performed over the same time period. Results: Increased expression of AQP2 was shown in the affected FN compared with its corresponding control at day 1 after compression, simultaneously with the appearance of facial palsy.     

Differences in glial,synaptic and motoneuron responses in the facial nucleus of the rat brainstem following facial nerve resection and nerve suture reanastomosis

Transection and reanastomosis of the facial nerve with microsurgical sutures in rats (facial-facial anastomosis) results in the complete regeneration of the facial nucleus, whereas resection of a 10 mm length of the peripheral facial nerve leads to degeneration and loss of neurons in the nucleus. Nerve sutures or resections were performed in 84 female Wistar rats, and the time course and differences between regenerative and degenerative reactions in the facial nuclei were compared after survival times of 4–112 days. The volume of the facial nucleus, number of facial motoneurons and motoneuron density were estimated stereologically by the physical dissector method. Synaptic plasticity, activation of astroglia and microglia were studied cytochemically with anti-synaptophysin, anti-glial fibrillary acidic protein and the isolectin Griffonia simplicifolia I-B₄ (GSA I-B₄). After facial-facial anastomosis the volume of the facial nucleus and its number of motoneurons remained constant, whereas resection of the facial nerve caused shrinkage of the facial nucleus and loss of one-third of facial motoneurons within 112 days post-operation. Synaptic stripping, activation of microglia and astroglia occurred in the same sequence and were reversible after both operations, but these reactions were more severe and prolonged after resection, i.e. without suture of the facial nerve. It appears to be most important clinically that differences between de- and regeneration become clear within 7 days post-axotomy. Our results strongly support reconstruction of the facial nerve as early as possible after a nerve lesion.     

Organization of the facial nerve nucleus in the cat

The location of efferent neurons in the brain stem of newborn kittens supplying the facial muscles was studied by means of horseradish perox-idase (HRP) used as a tracer of retrograde protein transport. Three to 15 microliters containing 0.3 to 1.5 mg of HRP was injected into the orbicu-laris oris and orbicularis oculi muscles of six kittens and in the seventh kitten, the ventral ramus of the facial nerve was transected and HRP was instilled on the cut end of the nerve. After a survival time of 24 hours, the animals were anesthetized, perfused by intracardic perfusion technique, and then they were fixed and the brain stems sectioned. Stains for peroxidase demonstrated the labelled neurons in the lateral division of facial nuclei in the ipsilateral side. The orbicularis oculi muscles were represented in the rostral pole of the lateral division of the facial nucleus dorsally while the orbicularis oris muscles were represented in the caudal pole of the lateral division of the facial nucleus ventrally. No labelled neurons were found in the nuclei of the Vth or any other brain stem nuclei. According to my knowledge, this method of localizing the neurons supplying the facial muscles has not been reported previously