The peripheral and central changes resulting from cutting or crushing the afferent nerve supply to the whiskers
The peripheral and central changes resulting from cutting or crushing the afferent nerve supply to the whiskers
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由于切断或挤压胡须的传入神经供应而引起的外周和中枢变化
DOI：
10.1098/rspb.1982.0004
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
B. Cragg
中科院分区：
文献类型：
--
作者：
P. Waite;B. Cragg
在新生大鼠，压碎或切断眶下神经，感觉神经供应胡须。可以防止皮质桶的形成。然而，这两个过程之后，三分之一到二分之一的神经纤维再生和胡须的神经再支配。通过对单个须囊神经中的纤维进行计数，已经表明在压碎后29-67%（平均45%）的有髓鞘纤维再生为须，而在切割后为24-56%（平均39%）。再生时程的研究表明，挤压和切割损伤之间存在进一步的差异。对正常、神经损伤和神经切断动物不同年龄段的再生纤维计数以及皮层诱发电位记录表明，与神经切断动物相比，神经损伤动物的恢复时间提前3-4天。在正常和神经压榨动物的诱发电位是第一次检测出生后2-3天，而神经切断后的反应不能记录，直到7天。即使在60天后，挤压和切割路径的反应幅度也仅为正常的三分之一左右，而潜伏期延长（正常5.8±0.25 ms，挤压6.5±0.26 ms，切割7.7±0.67 ms）。通过三叉神经核（第一突触水平）和躯体感觉皮层的微电极记录，研究了神经切断或挤压导致的中枢变化。这些也清楚地表明切割损伤的严重程度更高。因此，在压碎的动物中，三叉神经核的所有水平以及皮质仅显示出微小的变化。晶须占据相同的总面积，所有晶须的响应都存在于其正常部位。然而，神经切断后，三叉神经核和皮层的反应都显示出明显的异常。总的胡须面积减少，伴随着鼻子、脸颊、下颌以及眼睛和耳朵的胡须的反应扩大。此外，只有三分之一至二分之一的胡须作出反应。这些异常的部位局限于三叉神经核，因为所有的胡须都显示周围神经的神经支配。这表明，较长的恢复时间以及神经再支配的准确性降低可能有助于神经切断后的中枢恢复较差。
In neonatal rats, crushing or cutting the infraorbital nerve, the sensory nerve supply to the whiskers. has been found to prevent cortical barrel formation. However, both procedures are followed by regeneration of one-third to one-half of the nerve fibres and reinnervation of the whiskers. By counting fibres in individual whisker follicle nerves, it has been shown that 29–67% (mean 45%) of the myelinated fibres regenerate to the whiskers after a crush compared to 24–56% (mean 39%) after a cut. Further differences between the crush and cut lesions were indicated by studies on the time course of regeneration. Counts of the regenerating fibres at various ages as well as recordings of cortical evoked potentials in normal, nerve-crushed and nerve-cut animals showed that recovery was 3-4 days earlier in the nerve-crushed, compared with the nerve-cut animals. In normal and nerve-crushed animals the evoked potential was first detectable 2-3 days after birth while the response after nerve cut could not be recorded until day 7. Even after 60 days the amplitude of responses on both crushed and cut pathways was only about one-third of normal, while the latency was prolonged (normal 5.8±0.25 ms, crush 6.5±0.26 ms, cut 7.7±0.67 ms). Central changes occurring as a result of nerve cut or crush have been studied by microelectrode recordings from the trigeminal nucleus (the first synaptic level) and the somatosensory cortex. These also indicate clearly the greater severity of the cut lesion. Thus, in crushed animals, all levels of the trigeminal nucleus as well as the cortex show only minor modifications. The whiskers occupy the same total area and responses from all whiskers are present at their normal sites. However, after nerve cut, the responses from both the trigeminal nucleus and cortex show clear abnormalities. The total whisker area is reduced with a concomitant expansion of responses from the nose, check, lower jaw, and whiskers by the eye and ear. In addition, only one-third to one-half of the whiskers give responses. The site of these abnormalities is localized to the trigeminal nucleus since all whiskers show innervation in the peripheral nerve. It is suggested that the longer recovery time as well as the reduced accuracy of reinnervation may contribute to the poorer central recovery after a nerve cut.
DOI：
10.1113/jphysiol.1981.sp013664
发表时间：
1981-04
期刊：
The Journal of Physiology
影响因子：
--
作者：
K. Horch;S. Lisney
通讯作者：
K. Horch;S. Lisney