Peschanski M, Isacson O
Unité de Recherches de Neurophysiologie Pharmacologique, U 161 INSERM, Paris, France.
J Comp Neurol. 1988 Aug 15;274(3):449-63. doi: 10.1002/cne.902740311.
One month after an in situ injection of kainic acid into the ventrobasal thalamic complex (VB), the lesioned area is totally depleted of neurons. The present study has been undertaken to determine the cytoarchitecture and connectivity of the nucleus constructed by fetal thalamic neurons implanted into the excitotoxically lesioned area. Adult rats received an injection of kainic acid inducing a total neuronal depletion of the right lateral thalamus (including both the nucleus reticularis thalami and the lateral portion of the ventrobasal complex). One month later, homotypic neurons were taken from the dorsal thalamic primordium of rat embryos (gestational age 15-16 days), dissociated, and injected into the lesioned area as a cell suspension. After 2-4-month survival, the cytoarchitecture of the neonucleus formed by the grafted neurons within the previously neuron-depleted area was analyzed. Additionally, connectivity was analyzed in seven rats in which dorsal column nuclei and/or cortical projections to the area were labeled anterogradely with either 3H-leucine or wheat-germ agglutinin conjugated to HRP, and the animals were perfused and processed following various histological procedures (Nissl staining, autoradiographic processing, and histochemistry for visualization of peroxidase). Fetal neurons grew, differentiated, and progressively occupied the previously neuron-depleted area of the adult host CNS. They organized themselves into a neonucleus with particular cytoarchitectural features including 1) the existence of two concentric zones--a central zone containing neurons and glial cells and a marginal zone only filled with a band of glial cells, 2) an increase in cellular density compared to the intact thalamus, 3) the grouping of neurons in spherical clusters, and 4) apparent polymorphism of neuronal somata. Lemniscal and corticothalamic afferents originating from the host were observed in the neonucleus when the fetal neurons had been implanted correctly into the lesioned area but not when they had been misplaced into either normal thalamic tissue or the internal capsule. The afferents labeled from either the dorsal column nuclei or the somatosensory cortex were, however, less dense in the neonucleus than in the normal thalamus. These results are discussed with regard to the normal cytoarchitecture and connectivity of the ventrobasal complex of the rat thalamus.
在将海藻酸原位注射到腹侧基底丘脑复合体（VB）一个月后，损伤区域的神经元完全缺失。本研究旨在确定由植入兴奋性毒性损伤区域的胎儿丘脑神经元构建的核团的细胞结构和连接性。成年大鼠接受海藻酸注射，导致右侧丘脑外侧（包括丘脑网状核和腹侧基底复合体外侧部分）的神经元完全缺失。一个月后，从大鼠胚胎（妊娠15 - 16天）的背侧丘脑原基中取出同型神经元，解离后作为细胞悬液注射到损伤区域。在存活2 - 4个月后，分析先前神经元缺失区域内移植神经元形成的新核团的细胞结构。此外，对7只大鼠进行了连接性分析，在这些大鼠中，用3H - 亮氨酸或与辣根过氧化物酶（HRP）偶联的小麦胚芽凝集素对背柱核和/或投射到该区域的皮质进行顺行标记，然后按照各种组织学程序（尼氏染色、放射自显影处理以及用于过氧化物酶可视化的组织化学）对动物进行灌注和处理。胎儿神经元生长、分化并逐渐占据成年宿主中枢神经系统先前神经元缺失的区域。它们组织形成一个具有特定细胞结构特征的新核团，包括：1）存在两个同心区域——一个中央区域包含神经元和神经胶质细胞，一个边缘区域仅充满一层神经胶质细胞带；2）与完整丘脑相比细胞密度增加；3）神经元聚集成球形簇；4）神经元胞体明显多形性。当胎儿神经元正确植入损伤区域时，在新核团中观察到源自宿主的薄束和皮质丘脑传入纤维，但当它们错置于正常丘脑组织或内囊时则未观察到。然而，从背柱核或体感皮质标记的传入纤维在新核团中的密度低于正常丘脑。针对大鼠丘脑腹侧基底复合体的正常细胞结构和连接性对这些结果进行了讨论。
