Bragin A G, Bohne A, Vinogradova O S
Institute of Biophysics, U.S.S.R. Academy of Sciences, Moscow.
Neuroscience. 1988 Jun;25(3):751-8. doi: 10.1016/0306-4522(88)90034-6.
The degree of participation of grafted neurons in sensory analysis was investigated in embryonal rat somatosensory neocortex transplanted into the cavity at the place of the barrel field in the neocortex (SI) of adult rats. The neurons were investigated extracellularly 3 to 6 months after grafting. In the majority of grafts the neurons had normal levels and patterns of spontaneous activity. Many of them (65%) responded to displacement of the whiskers with latencies insignificantly different (18 +/- 0.8 ms) from those for reactions in the intact barrel field (16 +/- 0.5 ms). The receptive fields of the grafted neurons were very large. None of the neurons responded to stimulation of a single vibrissa, as in intact cortex. As a rule, the same neuron responded to isolated deflections of several (up to 10-20) vibrissae. Many of them were responsive to stimulation of the small anterior vibrissae and tactile stimulation of nose, limbs and body surface. Nevertheless, there was some spatial gradient in the effectiveness of stimulation of the body surface at various distances from the vibrissal pad; among effective vibrissae, usually several adjacent ones (2-4) produced larger responses with shorter latencies than the other ones. All units responded to painful stimuli irrespective of their location. The data show that the grafted neurons receive and may transmit sensory signals. The grafts which were proved histologically to be isolated from the host's brain did not respond to sensory stimulation and were characterized by the presence of aperiodic hypersynchronous bursts in their background activity. Electrophysiological criteria may be used for intravital diagnosis on the degree of the graft morphofunctional integration.
在成年大鼠新皮质（SI）桶状区位置的腔隙中移植胚胎大鼠体感新皮质，研究移植神经元参与感觉分析的程度。移植后3至6个月对神经元进行细胞外研究。在大多数移植组织中，神经元具有正常水平和自发活动模式。其中许多神经元（65%）对触须位移的反应潜伏期与完整桶状区的反应潜伏期无显著差异（18±0.8毫秒），而完整桶状区的反应潜伏期为16±0.5毫秒。移植神经元的感受野非常大。与完整皮质不同，没有一个神经元对单个触须的刺激产生反应。通常，同一个神经元对几根（多达10 - 20根）触须的单独偏转产生反应。其中许多神经元对小的前触须刺激以及鼻子、四肢和体表的触觉刺激有反应。然而，在距触须垫不同距离处刺激体表的有效性存在一定的空间梯度；在有效的触须中，通常有几根相邻的触须（2 - 4根）比其他触须产生更大的反应且潜伏期更短。所有单位对疼痛刺激均有反应，无论其位置如何。数据表明移植神经元接收并可能传递感觉信号。经组织学证实与宿主脑分离的移植组织对感觉刺激无反应，其背景活动的特征是存在非周期性超同步爆发。电生理标准可用于活体诊断移植形态功能整合的程度。
