Rearrangement of neuronal responses in the trigeminal system of the rat following peripheral nerve section.
Rearrangement of neuronal responses in the trigeminal system of the rat following peripheral nerve section.
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周围神经切片后大鼠三叉神经系统神经元反应的重新排列。
DOI：
10.1113/jphysiol.1984.sp015301
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
P. Waite
中科院分区：
文献类型：
--
作者：
P. Waite
在新生大鼠（0天）或成年大鼠（60天）中切断眶下神经，阻止外周再生。60天后，无论是解剖或电生理技术研究周围神经，三叉神经核和体感皮层。在解剖切片的动物中，在60天时，在病变近端的周围神经中存活的有髓纤维的数量为11%，而成人神经切片后存活率为100%。脊髓损伤动物中存活神经纤维的减少与所有三叉神经核（主核、口核、极间核和尾核）的横截面积显著减少18 - 29%相关。切片为成年动物的面积无显著变化。新生儿损伤的动物也显示出在所有三叉神经核的横截面中可见的细胞数量减少约20%。新生动物切片显示出显着的可塑性在所有核的三叉神经复合体以及在皮质。去传入神经细胞对新的外周感受野作出反应，从而修改了这些细胞的躯体组织。这种细胞在全文中被称为“再活化”细胞。然而，在动物切片成人没有证据的可塑性可以检测到三叉神经核。只有非常有限的再激活是明显的皮质，所以大多数的deafferented细胞在这两个网站仍然没有反应。对第0天神经切片动物主核的23个再活化细胞和25个正常细胞进行了详细比较。虽然刺激阈值相似，但被激活的细胞通常表现出更大、更复杂的感受野、更长的潜伏期和更低的跟随频率。因此，重新激活的细胞表现出比正常细胞更多的收敛和更差的突触安全性。然而，刺激对侧丘脑产生了类似的反应，从两组细胞，这表明并不是所有的输入重新激活的细胞被修改。在第0天损伤的动物尾侧核中细胞再活化的时间过程被跟踪超过30天。未检测到长达24小时的急性效应。然而，躯体位置重组已开始的第7天，迅速进行之间的第7和第14天，并完成了第21天。
The infraorbital nerve was cut in either neonatal (on day 0) or adult (day 60) rats and the peripheral regeneration prevented. After 60 days either anatomical or electrophysiological techniques were used to study the peripheral nerve, trigeminal nucleus and somatosensory cortex. In neonatally sectioned animals the number of myelinated fibres surviving, at 60 days, in the peripheral nerve proximal to the lesion was 11% compared with 100% survival after adult nerve section. This reduction in surviving nerve fibres in neonatally lesioned animals was associated with a significant reduction in cross‐sectional area of all trigeminal nuclei (principalis, oralis, interpolaris and caudalis) of 18‐29%. No significant change in area was present in animals sectioned as adults. Neonatally lesioned animals also showed a reduction of approximately 20% in the number of cells visible in cross‐sections of all trigeminal nuclei. Animals sectioned as neonates showed marked plasticity at all nuclei in the trigeminal complex as well as in the cortex. Deafferented cells responded to new peripheral receptive fields so that the somatotopic organization of these cells was modified. Such cells are referred to throughout as 'reactivated' cells. However, in animals sectioned as adults no evidence of plasticity could be detected in the trigeminal nuclei. Only very limited reactivation was apparent in the cortex, so that the majority of deafferented cells remained unresponsive at both sites. A detailed comparison was made of twenty‐three reactivated cells and twenty‐five normal cells from nucleus principalis of animals with nerve section on day 0. The reactivated cells commonly showed larger, more complex receptive fields, longer latencies and lower following frequencies, although stimulus thresholds were similar. Thus reactivated cells showed more convergence and poorer synaptic security than normal cells. However, stimulation of the contralateral thalamus produced similar responses from both groups of cells, suggesting that not all inputs to reactivated cells were modified. The time course of the reactivation of cells in nucleus caudalis from animals lesioned on day 0 was followed over 30 days. No acute effect, for up to 24 h, was detected. However, somatotopic reorganization had started by day 7, proceeded rapidly between days 7 and 14, and was completed by day 21.