应用于电生理学研究的动眼神经损伤动物模型的建立

目的建立适用于电生理学研究具有良好可行性及可重复性的实验犬动眼神经损伤动物模型，探讨模拟动眼神经生物电活动的生理性电刺激参数。方法10只雌性Beagle犬常规开颅暴露动眼神经海绵窦后段，以不同强度电刺激动眼神经，采集下斜肌肌细胞复合动作电位后，将动眼神经锐性切断，再予直接端-端吻合。结果伞部实验步骤均能被Beagle犬耐受，幕下段动眼神经充分暴露，刺激电极可顺利置入，并获得下斜肌理想的生物电信号。结论实验犬动眼神经损伤动物模型已经建立，并具有良好可重复性，为选择模拟动眼神经生物电活动的适宜刺激参数提供实验依据，以进一步用于日后动眼神经功能修复的电生理学研究。     

动眼神经电刺激对健康Beagle犬下斜肌CMAP的影响研究

目的 研究动眼神经电刺激对Beagle犬下斜肌复合动作电位（CMAP）的影响,为动眼神经损伤后的电刺激治疗提供依据.方法 对10只健康雌性Beagle犬行常规开颅,暴露动眼神经海绵窦后段,以不同强度电刺激动眼神经,采集下斜肌CMAP.结果 随着电刺激强度的递增,下斜肌CMAP峰值逐渐增加.直接刺激动眼神经干的适宜强度为0.9～1.6 V,可使下斜肌CMAP峰值达到500 μV左右.结论 给予动眼神经一定强度的电刺激,可以在眼外肌上诱发出稳定的动作电位.该结果对动眼神经损伤后的功能重建有潜在的应用价值.     

人用DBS系统在脑深部电刺激猴模型构建中的应用

目的探讨人用脑深部电刺激(DBS)系统在构建猴脑深部电刺激模型中的应用。方法 4只偏侧帕金森病(PD)猴模型,按照猴脑立体定向图谱,在右侧丘脑底核(STN)植入脑深部刺激电极(Medtronic 3389),其中刺激组2只猴同期皮下植入Medtronic 7495型连接导线和Soletra TM7426型脉冲发生器,术后一周给予慢性高频电刺激。另2只偏侧PD模型猴仅在右侧STN植入电极,不植入脉冲发生器,作为对照组。连续观察12个月,进行运动障碍评分观察和阿朴吗啡(APO)诱发旋转实验。结果术后影像学观察电极前端均位于STN核范围内;刺激组同期植入脉冲发生器给予慢性高频电刺激,猴偏侧帕金森样症状明显改善,有效高频电刺激可以立即停止APO所诱发的旋转,而对照组在观察期内症状无明显缓解。结论人用DBS系统通过立体定向技术植入猴脑内特定靶点,可以有效的建立DBS动物模型,为DBS在神经系统疾病中的应用研究提供了良好的实验模型。     

猫动眼神经的形态学特征及其横断伤修复模型

目的 为动眼神经损伤后修复与再生研究提供适合的动物模型.方法 家猫32只,选右侧动眼神经为实验对象,经右侧颞下人路显露同侧动眼神经,观测动眼神经的形态学特征及端端吻合、神经桥接和导管套接修复动眼神经的手术方法.结果 体重3kg左右猫的动眼神经脑池段长约5mm,粗约0.8~1.0mm,由9,456±296根有髓神经纤维组成,其颅内段神经缺乏神经外膜和神经束膜层,仅被单层扁平成纤维细胞包裹.颞下人路能较好地显露动眼神经,如显露其海绵窦段则有利于导管及神经移植修复的研究.结论 猫是研究端端吻合、神经桥接及导管套接修复动眼神经的适合动物.     

电针对Beagle犬展神经损伤后小胶质细胞活化状态的影响

目的通过进行Beagle犬展神经损伤模型制作,探讨展神经损伤后小胶质细胞表型变化及电针刺激后小胶质细胞活化状态的改变。方法选用健康雄性成年Beagle犬随机分为三组:假手术组(A)、损伤组(B)和电针处理组(C)。A组仅进行展神经游离,B组、C组均进行展神经损伤模型制作,C组进行展神经刺激电极及外直肌记录电极植入。术后4 w后均取材进行Western Blot检测,分析展神经小胶质细胞M1、M2型标志分子的表达水平,进行统计学分析。结果与损伤组相比,电针组M1型表达分子i NOS及IL-1β表达均降低(P 0. 05);而电针组M2型表达分子Arginase及BDNF表达较损伤组均增加(P 0. 05)。结论展神经损伤后以M1型标志分子为主,电针刺激能够显著升高M2型转化。     

神经桥接与导管套接修复猫动眼神经形态学观察

目的探求导管修复颅内段动眼神经的可行性.方法 20只健康家猫随机分为2组.将右侧动眼神经于脑池段切断后,分组采用自体神经桥接和导管套接的方法修复.术后14周末光镜、电镜观察神经纤维的连续性、再生纤维数目和直径.结果神经修复14周后,神经桥接组67%、导管套接组75%的动物其动眼神经功能均有一定程度的恢复.形态学显示两组均取得较好的神经再生效果,两组间再生纤维直径差异无显著性(P>0.05),但导管套接组再生神经纤维数目较多,差异有显著性(P<0.05).结论导管套接法可作为颅内段动眼神经损伤后的一种修复方法,其疗效近似或稍优于神经桥接法.     

脑深部电刺激猴帕金森病模型的建立

目的通过猴偏侧帕金森病（Parkinson disease,PD）模型丘脑底核（subthalamic nucleus,STN）脑深部电刺激（deep brain stimulation,DBS）系统的植入,对脑深部电刺激动物模型的制备进行了探讨.方法2只猴偏侧PD模型,按照猴脑立体定向图谱,在右侧STN植入脑深部刺激电极,并同期皮下植入脉冲发生器.术后行头颅X线平片和MRI检查,给予慢性高频电刺激,观察运动症状改善.结果2只偏侧猴PD模型成功的同期植入DBS系统,术后的症状观察和阿朴吗啡（apomorphine,APO）诱发旋转实验,证实STN慢性高频电刺激有效地缓解了猴PD样症状.结论通过立体定向技术同期将DBS系统植入动物体内,可以有效的建立DBS动物模型,为DBS在神经疾病的应用研究提供了良好的实验模型.     

电刺激致颈神经椎孔外卡压动物模型的建立及相关刺激参数的选择

[摘要]目的 初步研究不同刺激参数对大鼠肌肉收缩的影响,探讨局部电刺激致椎孔外颈神经卡压的可能性,为今后进一步开展各项研究提供依据。方法 （1）应用各种模式的电刺激对大鼠的颈项部肌群进行刺激,观察局部及全身对各种刺激的反应;同时记录局部肌电变化。(2)研制微型电脉冲神经肌肉刺激器,设定合适的刺激参数,经预处理后植入成年SD大鼠体内。予以每天8小时间隙电刺激。于植入后的2、3、4、5周观察动物形为改变。行电生理检测后,处死动物后取材行各项组织学检测,结果进行统计学分析。结果 (1) 在刺激频率不变的前提下,随脉宽的增加（50-200μs）,肌电幅值显著上升。且肌电幅值的变化与大鼠行为改变成正相关。以下参数：50Hz、200μs、刺激间隔时间1/3s、20V十分适合建立颈部肌痉挛动物模型。(2)经颈部局部刺激后,电生理检测可见失神经电位。光镜检测提示存在神经卡压的病理改变。电镜检测示髓鞘变性,炎性细胞浸润。结论 不同的刺激参数可影响肌肉的收缩状态与强度,局部电刺激的方法可用于建立椎孔外颈神经卡压综合征的动物模型。颈神经后支卡压可能为椎孔外卡压综合征产生的启动因素。 [关键词] 慢性颈肩痛 电刺激 刺激参数 椎孔外颈神经卡压 动物模型     

SD大鼠动眼神经不同部位损伤后对靶器官特异性支配的实验研究

目的研究不同部位损伤对Sprague-Dawley（SD）大鼠动眼神经功能修复的影响及可能机制。方法实验Ⅰ组大鼠（n=24）经幕下、实验Ⅱ组（n=24）大鼠经眶上裂干预动眼神经，术后通过前庭眼反射评估眼外肌在垂直、水平方向的恢复程度。经右侧上直肌注射辣根过氧化酶（HRP），逆行追踪中脑动眼神经核团内神经元分布；48h后行动眼神经组织学、解剖学研究。结果实验Ⅰ组大鼠支配上直肌的神经纤维有45％～51％由对侧中脑运动神经元发出：实验Ⅱ组81％～87％由对侧中脑运动神经元发出，神经元在中脑的分布更接近正常大鼠。实验Ⅱ组大鼠眼外肌功能恢复程度明显优于实验Ⅰ组大鼠。结论动眼神经损伤部位距离眼外肌越近，最终的神经功能恢复水平越好，这可能与再生神经纤维通过损伤部位时的迷行程度相关。     

Framelink手术规划结合微电极电生理监测在DBS治疗帕金森病中的应用

目的探讨Framelink手术计划系统结合微电极电生理监测技术在帕金森病脑深部电刺激术(DBS)中的临床应用。方法回顾性分析7例接受丘脑底核-脑深部电刺激(STN-DBS)治疗的帕金森病人的临床资料。术前应用Framelink手术计划系统行STN靶点定位,术中采用Lead-Point微电极记录细胞外放电进行STN验证和电刺激,观察病人症状改善及不良反应发生情况。比较影像解剖STN与功能STN核团长度。结果 Framelink手术计划系统的应用,使术中STN核清晰可见。共植入电极9根(左侧3根,右侧6根),其中8根(88.9%)微电极一次成功定位。共用MER针道10道,每植入1根电极平均需要1.1针道,针道更换率为11%。术后颅脑CT证实,电极位置满意100%,无颅内血肿发生。影像解剖STN核与功能STN核长度无明显差异(P0.05)。结论 Framelink手术计划系统结合微电极电生理监测技术可提高脑深部电极植入靶点的准确性,减少穿刺次数,降低手术并发症,提高手术疗效。     

功能性电刺激干预损伤动眼神经的肌电图评估

Functional electrical stimulation delivered early after injury to the proximal nerve stump has been proposed as a therapeutic approach for enhancing the speed and specificity of axonal regeneration following nerve injury. In this study, the injured oculomotor nerve was stimulated functionally by an implantable electrode. Electromyographic monitoring of the motor unit potential of the inferior oblique muscle was conducted for 12 weeks in two injury groups, one with and one without electric stimulation. The results revealed that, at 2, 4, 6, 8 weeks after functional electric stimulation of the injured oculomotor nerve, motor unit potentials significantly increased, such that amplitude was longer and spike duration gradually shortened. These findings indicate that the injured oculomotor nerve has the potential for regeneration and repair, but this ability is not sufficient for full functional recovery to occur. Importantly, the current results indicated that recovery and regeneration of the injured oculomotor nerve can be promoted with functional electrical stimulation.     

Establishment of a beagle dog model of oculomotor nerve injury

The oculomotor nerves of beagle dogs received electrical stimulation at 0.3-2.0 V. After recording compound muscle action potentials of the inferior oblique muscle, the oculomotor nerve was quickly cut off and a direct end-to-end anastomosis was then performed. As a result, the stimulating elec-trode was smoothly inserted and placed, and ideal bioelectrical signals of the interior oblique muscle were acquired. After oculomotor nerve injury, compound muscle action potentials of the inferior oblique muscle were significantly decreased in beagle dogs. These findings suggest that an animal model of oculomotor nerve injury was successfully established for electrophysiological studies.     

Electrical stimulation promotes regeneration of injured oculomotor nerves in dogs

Functional recovery atfer oculomotor nerve injury is very poor. Electrical stimulation has been shown to promote regeneration of injured nerves. We hypothesized that electrical stimulation would improve the functional recovery of injured oculomotor nerves. Oculomotor nerve injury models were created by crushing the right oculomotor nerves of adult dogs. Stimulating electrodes were positioned in both proximal and distal locations of the lesion, and non-continuous rectangular, biphasic current pulses (0.7 V, 5 Hz) were administered 1 hour daily for 2 consecutive weeks. Analysis of the results showed that electrophysiological and morphological recovery of the injured oc-ulomotor nerve was enhanced, indicating that electrical stimulation improved neural regeneration. hTus, this therapy has the potential to promote the recovery of oculomotor nerve dysfunction.     

A standardized method to create peripheral nerve injury in dogs using an automatic non-serrated forceps

This study describes a method that not only generates an automatic and standardized crush injury in the skull base, but also provides investigators with the option to choose from a range of varying pressure levels. We designed an automatic, non-serrated forceps that exerts a varying force of 0 to 100 g and lasts for a defined period of 0 to 60 seconds. This device was then used to generate a crush injury to the right oculomotor nerve of dogs with a force of 10 g for 15 seconds, resulting in a deficit in the pupil-light reflex and ptosis. Further testing of our model with Toluidine-blue staining demonstrated that, at 2 weeks post-surgery disordered oculomotor nerve fibers, axonal loss, and a thinner than normal myelin sheath were visible. Electrophysiological examination showed occasional spontaneous potentials. Together, these data verified that the model for oculomotor nerve injury was successful, and that the forceps we designed can be used to establish standard mechanical injury models of peripheral nerves.     

Assessment of rat sciatic nerve function following acute implantation of high density utah slanted electrode array (25 electrodes/mm2) based on neural recordings and evoked muscle activity

Introduction: High density Utah slanted electrode arrays (HD‐USEAs) have been developed recently for intrafascicular access to submillimeter neural structures. Insertion of such high electrode density devices may cause nerve crush injury, counteracting the intended improved selective nerve fiber access. Methods: HD‐USEAs were implanted into sciatic nerves of anesthetized rats. Nerve function was assessed before and after HD‐USEA implantation by measuring changes in evoked muscle and nerve compound action potentials and single unit neuronal recordings. Results: Neural activity was recorded with over half of all implanted electrodes. Average decreases of 38%, 36%, and 13% in nerve, medial gastrocnemius, and tibialis anterior compound action potential amplitudes, respectively, were observed following array implantation. Only 1 of 8 implantations resulted in loss of all signals. Conclusions: These studies demonstrate that HD‐USEAs provide a useful neural interface without causing a nerve crush injury that would otherwise negate their use in acute preparations (<12 h). Muscle Nerve 50 : 417–424, 2014     

Primary aberrant third nerve regeneration

The clinical and neuroradiological features in 4 patients with the syndrome of aberrant regeneration of the third nerve are presented. In contrast to what is commonly seen, the syndrome was not preceded by third nerve palsy. A petrous apex-cavernous sinus meningioma was the underlying lesion in all 4 patients. Surgical and pathological confirmation of the diagnosis was obtained in 3. Regardless of whether the other ocular motor nerves are spared (as in our patients) or involved (as in other cases reported in the literature), primary aberrant regeneration of the oculomotor nerve appears to be characteristic of a cavernous sinus meningioma.     

A case of Tolosa-Hunt syndrome starting from abducens nerve palsy alone]

A 59-year-old man was admitted to our hospital because of right abducens nerve palsy without orbital pain. One month later right orbital pain appeared and two months later the pain changed to an aching severe pain and the right oculomotor, trochlear and trigeminal nerves were also involved. The administration of corticosteroid dramatically reduced these symptoms. The diagnosis was Tolosa-Hunt syndrome (THS) based on these findings. THS starting with abducens nerve palsy alone is rare, representing only 5.1% of 118 patients. In our patient, the newly developed dynamic MRI was able to reveal the right cavernous sinus lesion. The diagnostic usefulness of dynamic MRI for cavernous sinus lesions has been demonstrated for such cases.     

Trigeminal afferent fibers in the trunk of the oculomotor nerve of lambs.

In lambs, chronic section of the oculomotor nerve at the base of the skull just proximally to the cavernous sinus induced degeneration of some fibers in the central stump, although the peripheral stump contained some normal fibers. On the other hand, chronic section of the ophthalmic branch just distally to the semilunar ganglion was followed by degeneration of a certain number of medium and large caliber fibers in the ipsilateral oculomotor nerve. The presence of trigeminal afferent fibers in the trunk of an oculomotor nerve is supported by electrophysiologic experiments. Single-shock electrical stimulation of the frontal and nasociliary nerves and of the conjunctiva of the superior and inferior eyelids elicited short-latency evoked potentials, not only in the semilunar ganglion but also in the ipsilateral oculomotor nerve at the base of the skull. Such responses did not appear in those animals in which the ipsilateral ophthalmic and maxillary branches of the trigeminal nerve had been chronically cut. Thus, we can affirm that afferent trigeminal impulses enter the brain stem also through the third nerve. The perikarya of such a pathway are localized in the semilunar ganglion; the peripheral processes attain the conjunctiva of the superior and inferior eyelids through the ophthalmic and maxillary branches, and the central processes enter the oculomotor nerve by anastomoses between IIIrd and Vth cranial nerves after a short passage in the two trigeminal branches. The trigeminal nature of these fibers is also shown by the fact that electrical stimulation of the central stump of the IIIrd nerve can influence the dorsal neck muscles in the same way as other trigeminal afferents.     

Reduced efficacy of nitrergic neurotransmission exacerbates erectile dysfunction after penile nerve injury despite axonal regeneration

Penile (cavernous) nerves are readily damaged during radical prostatectomy, invariably causing impotence. Erectile function can return, however this may take months or years and capacity often remains poor. Many studies have attempted to improve penile nerve regeneration but have not explored mechanisms underlying the delay in functional recovery. This is assumed to be due to slow growth of axons, although penile tissues also change following loss of erectile activity. We have asked whether delayed recovery of the nitrergic nerve-evoked erectile response is due to pre-synaptic (slow axonal growth) or post-synaptic (changes in tissue responsiveness) mechanisms. These components were dissected in vitro following penile nerve injury in adult rats. Following crush of both penile nerves, excellent regeneration of nitrergic axons occurred after 10-12 weeks but neurogenic relaxation of cavernosum muscle was still relatively poor. This was at least partly due to attenuated tissue responsiveness to nitric oxide (using sodium nitroprusside as a donor) from 3 weeks after injury. Western blotting also revealed a modest reduction of soluble guanylyl cyclase. A second model of penile nerve injury, unilateral cut, completely denervated one side but retained potential for penile erection. Some anatomical and functional recovery occurred after 9-11 weeks (probably due to sprouting from contralateral uninjured axons), but nitroprusside-evoked relaxations were unaltered from at least 3 weeks onward. These data suggest that erectile dysfunction following extensive nerve injury may be exacerbated by postsynaptic changes in nitric oxide signaling, even when nerve regeneration occurs. This may be prevented by continued activation of penile tissues to retain normal perfusion.