De Zeeuw C I, Ruigrok T J
Department of Anatomy, Erasmus University of Rotterdam, The Netherlands.
Brain Res. 1994 Aug 8;653(1-2):345-50. doi: 10.1016/0006-8993(94)90411-1.
The direct projection from the cerebellar nuclei to the inferior olive is GABAergic. In the present study, we investigated the projection from the cerebellar nuclei to the mesodiencephalic junction which is known to provide an excitatory projection to the inferior olive. The mesodiencephalic junction was studied in cat following anterograde transport of wheatgerm agglutinated horseradish peroxidase from the cerebellar nuclei in combination with: (1) retrograde transport of gold-lectin conjugate from the inferior olive; and (2) postembedding GABA-immunocytochemistry. Light microscopic analysis revealed that overlap of the anterograde and retrograde labeling was especially prominent in the nucleus of Darkschewitsch. Electron microscopic examination of this area showed: (1) that many cerebellar terminals made synaptic contacts with neurons that project to the inferior olive; (2) that virtually all cerebellar terminals were non-GABAergic and displayed an excitatory morphology; and (3) olivary projecting neurons were non-GABAergic. It is concluded that the indirect cerebellar projection to the inferior olive via the nucleus of Darkschewitsch is disynaptic and excitatory.
从小脑核到下橄榄核的直接投射是γ-氨基丁酸能的。在本研究中，我们研究了从小脑核到中脑间脑交界处的投射，已知该交界处向下橄榄核提供兴奋性投射。在猫身上，通过从小脑核进行小麦胚芽凝集辣根过氧化物酶的顺行运输，并结合以下方法对中脑间脑交界处进行了研究：（1）从下橄榄核进行金凝集素共轭物的逆行运输；（2）包埋后γ-氨基丁酸免疫细胞化学。光学显微镜分析显示，顺行和逆行标记的重叠在达克谢维奇核中尤为突出。对该区域的电子显微镜检查显示：（1）许多小脑终末与投射到下橄榄核的神经元形成突触联系；（2）几乎所有小脑终末都是非γ-氨基丁酸能的，并表现出兴奋性形态；（3）橄榄核投射神经元是非γ-氨基丁酸能的。得出的结论是，通过达克谢维奇核到下橄榄核的间接小脑投射是双突触且兴奋性的。
