Wannier T, Kakei S, Shinoda Y
Department of Physiology, School of Medicine, Tokyo Medical and Dental University, Japan.
Exp Brain Res. 1992;90(2):241-52. doi: 10.1007/BF00227235.
The characteristics of cerebellar input to the parietal cortex through the ventroanterior-ventrolateral (VA-VL) complex of the thalamus were investigated in the adult cat by using combined electrophysiological and anatomical methods. Two distinct parietal regions were activated by stimulation of the cerebellar nuclei (CN). In the first region located in the depth of the bank of the ansate sulcus, stimulation of the CN induced early surface positive-deep negative potentials and late surface negative-deep positive potentials. In this cortical area, potentials of similar shape and time course were evoked at a shorter latency by stimulation of the ventrolateral part of the VA-VL complex where large negative field potentials were evoked by stimulation of the CN. After injection of the anterograde tracer Phaseolus vulgaris leucoagglutinin (PHA-L) in this part of the VA-VL complex, axon terminals of thalamocortical (TC) fibers were found in layers I, III and IV in the depth of the bank of the ansate sulcus and layers I and III in the motor cortex. In the second region located in the suprasylvian gyrus, late surface negative-deep positive potentials were evoked by stimulation of the CN and similar potentials were evoked at a shorter latency from the dorsomedial part of the VA-VL complex where large cerebellar-evoked potentials could be recorded. PHA-L injection in this thalamic region stained TC fibers and their terminals in layer I of the suprasylvian gyrus, and in layers I and III of the motor cortex. The laminar distribution of TC axon terminals in two different regions of the parietal cortex could account for the depth profiles of the cerebellar- and the thalamic-evoked potentials in each region. These results show that cerebellar information is conveyed to two separate areas in the parietal cortex by two different TC pathways.
运用电生理与解剖学相结合的方法，在成年猫中研究了小脑经丘脑腹前核-腹外侧核（VA-VL复合体）向顶叶皮质输入的特征。刺激小脑核（CN）可激活两个不同的顶叶区域。在第一个区域，位于袢沟岸的深部，刺激CN诱发早期表面正波-深部负波电位和晚期表面负波-深部正波电位。在这个皮质区域，刺激VA-VL复合体的腹外侧部分可在更短的潜伏期诱发形状和时程相似的电位，而刺激CN在该区域可诱发大的负向场电位。在VA-VL复合体的这一部分注射顺行示踪剂菜豆凝集素（PHA-L）后，在袢沟岸深部的I、III和IV层以及运动皮质的I和III层发现了丘脑皮质（TC）纤维的轴突终末。在位于上薛氏回的第二个区域，刺激CN诱发晚期表面负波-深部正波电位，从VA-VL复合体的背内侧部分在更短的潜伏期可诱发类似电位，在该区域可记录到较大的小脑诱发电位。在这个丘脑区域注射PHA-L可使上薛氏回I层以及运动皮质I和III层的TC纤维及其终末染色。TC轴突终末在顶叶皮质两个不同区域的分层分布可以解释每个区域小脑和丘脑诱发电位的深度分布情况。这些结果表明，小脑信息通过两条不同的TC通路传递到顶叶皮质的两个不同区域。
