Rosina A, Provini L
J Comp Neurol. 1987 Feb 15;256(3):317-28. doi: 10.1002/cne.902560302.
The aim of this study was to define the overall distribution pattern of the axon collaterals of single inferior olive (IO) neurons in relation to the multiple somatotopic maps defined by the climbing fiber (CF) input through the cerebellar cortex. In a previous study (Rosina and Provini: Brain Res. 289:45-63, '83), it was shown that the IO neurons supply interlobar collaterals to pairs of somatotopically related areas in the intermediate part of the anterior lobe (PIAL), in the paramedian lobule (PML), in crus II, and in the simple lobule, within strips C1 to D2. The residual branches then could either distribute within single folia or to adjacent folia within each somatotopically defined cerebellar area or both. We studied whether or not the IO axons branch over neighboring folia of the face-forelimb (FL) areas of PIAL and PML and how this interfolial branching relates to the interlobar collateralization by using the multiple fluorescent retrograde tracing technique. The main results of the study were as follows: the axons from neurons in IO subdivisions that are related to strips C1-C3 give off two interfolial branches in the FL area of PIAL and practically no interfolial collaterals are given in the FL area of PML; and the neurons that give off interfolial collaterals also give interlobar branches. From these data we have inferred the general branching pattern of the IO neurons that convey FL information to PIAL and PML. Each neuron gives off two interlobar collaterals: the branch directed to PIAL splits again into two interfolial collaterals, while each of these three collaterals should give off about three branches within each target folium to account for the ten collaterals estimated to be present in the cat. The distribution pattern of IO axon collaterals proposed here suggests that the same CF-relayed information may interact, at the Purkinje cell level, with different sets of mossy fiber inputs. The effect of this interaction would be to modulate the motor commands forwarded to specific muscle groups in relation to the different conditions under which a given movement is executed.
本研究的目的是确定单个下橄榄核（IO）神经元轴突侧支的整体分布模式，及其与通过小脑皮质的攀爬纤维（CF）输入所定义的多个躯体定位图的关系。在先前的一项研究中（Rosina和Provini：《脑研究》289：45 - 63，'83），研究表明IO神经元在前叶中间部分（PIAL）、旁正中小叶（PML）、小脑 crus II和简单小叶中，在C1至D2条带内，向成对的躯体定位相关区域提供叶间侧支。其余分支则可分布在单个小叶内，或分布在每个躯体定位定义的小脑区域内的相邻小叶中，或两者皆有。我们使用多重荧光逆行追踪技术研究了IO轴突是否在PIAL和PML的面 - 前肢（FL）区域的相邻小叶上分支，以及这种小叶间分支与叶间侧支形成的关系。该研究的主要结果如下：与C1 - C3条带相关的IO亚区神经元的轴突在PIAL的FL区域发出两个小叶间分支，而在PML的FL区域几乎不发出小叶间侧支；发出小叶间侧支的神经元也发出叶间分支。从这些数据中，我们推断出了将FL信息传递到PIAL和PML的IO神经元的一般分支模式。每个神经元发出两个叶间侧支：指向PIAL的分支再次分裂为两个小叶间侧支，而这三个侧支中的每一个在每个目标小叶内大约应发出三个分支，以解释估计猫体内存在的十条侧支。这里提出的IO轴突侧支的分布模式表明，相同的CF中继信息可能在浦肯野细胞水平上与不同组的苔藓纤维输入相互作用。这种相互作用的效果将是根据执行给定运动的不同条件，调节转发给特定肌肉群的运动指令。
