Nakamura Y, Kitao Y, Moriizumi T, Kudo M
J Comp Neurol. 1987 Apr 22;258(4):611-21. doi: 10.1002/cne.902580410.
Rubral neurons sending axons to the cerebellar anterior interpositus nucleus (AIN) in the cat were identified light microscopically by labeling them with horseradish peroxidase (HRP). The synaptic organization of these rubral neurons and of their afferents from the cerebral motor cortex and the AIN was also analyzed electron microscopically by combined anterograde degeneration and retrograde HRP-labeling techniques. In the light microscopic study, either HRP or a mixture of HRP and kainic acid was injected into the AIN. Both of the injections resulted in retrograde labeling of rubrocerebellar projection neurons in the red nucleus on the contralateral side. The labeled neurons were distributed throughout the rostrocaudal extent of the red nucleus: some lay in clusters. Most labeled neurons were small to medium-sized, although some were large. The injection of HRP into the AIN also resulted in anterograde labeling of cerebellorubral projection fibers terminating in a wider area of the red nucleus on the contralateral side of the injection, whereas the injection of a mixture of HRP and kainic acid showed no anterograde labeling of fibers or terminals. In one set of electron microscopic observations, HRP injections into the AIN were combined with ablation of the motor cortex. Degenerating axon terminals were occasionally found to synapse with both dendrites and neuronal somata labeled with HRP retrogradely. In another set of electron microscopic observations, a mixture of HRP and kainic acid was injected into the AIN in order to label rubrocerebellar projection neurons retrogradely and to bring about degeneration in the cerebellorubral projection fibers anterogradely. Abundant degenerating axon terminals were observed to make axosomatic synaptic contacts with rubral neurons labeled with HRP retrogradely and also with unlabeled rubral neurons. These results indicate that cerebrorubrocerebellar and rubrocerebellorubral monosynaptic circuitries exist which constitute one of the cerebrocerebellar linkages, as well as those linkages via the inferior olivary complex and the pontine nuclei.
通过用辣根过氧化物酶（HRP）标记，在光学显微镜下鉴定了向猫小脑前间位核（AIN）发送轴突的红核神经元。还通过联合顺行性变性和逆行HRP标记技术，在电子显微镜下分析了这些红核神经元及其来自大脑运动皮层和AIN的传入神经的突触组织。在光学显微镜研究中，将HRP或HRP与 kainic 酸的混合物注入AIN。两种注射均导致对侧红核中红核小脑投射神经元的逆行标记。标记的神经元分布在红核的整个前后范围内：一些聚集成簇。大多数标记的神经元是中小型的，尽管有些是大型的。将HRP注入AIN还导致小脑红核投射纤维在注射对侧的红核更广泛区域内终末的顺行标记，而注射HRP和kainic酸的混合物则未显示纤维或终末的顺行标记。在一组电子显微镜观察中，将HRP注入AIN与运动皮层的切除相结合。偶尔发现退化的轴突终末与逆行标记有HRP的树突和神经元胞体都形成突触。在另一组电子显微镜观察中，将HRP和kainic酸的混合物注入AIN，以便逆行标记红核小脑投射神经元并使小脑红核投射纤维顺行性退变。观察到大量退化的轴突终末与逆行标记有HRP的红核神经元以及未标记的红核神经元形成轴体突触接触。这些结果表明，存在大脑 - 红核 - 小脑和红核 - 小脑 - 红核单突触回路，它们构成了大脑小脑联系之一，以及通过下橄榄复合体和脑桥核的那些联系。
