Nelson B J, Mugnaini E
Laboratory of Neuromorphology, University of Connecticut, Storrs 06268.
Anat Embryol (Berl). 1988;179(2):109-27. doi: 10.1007/BF00304693.
Boutons presumed to use gamma-aminobutyric acid as neurotransmitter (GABAergic boutons) were detected by glutamate decarboxylase (GAD) immunocytochemistry in all regions of the rat inferior olive. The remarkably high concentration of these boutons allowed a clear visualization of olivary subnuclei boundaries. Regional variations in GAD immunostaining intensity were observed within the nuclear complex and were graded both visually and photometrically. The regional staining variations, for the most part, followed subnuclei boundaries and olivary zonal compartments that have been delineated by the topography of climbing fibre projections. Some subnuclei were grouped by similar staining intensities. The beta nucleus and a medial region in the ventral fold of the dorsal accessory olive were most intensely immunostained, followed by the subnucleus c of the medial accessory olive. Lower staining intensities were observed in the dorsomedial cell column, the dorsal fold of the dorsal accessory olive and the dorsal cap. The lowest intensities were observed in the subnuclei a and b of the medial accessory olive, the ventrolateral outgrowth, the rostral lamella of the medial accessory olive, the principal olive, and the lateral part of the ventral fold of the dorsal accessory olive. The factors contributing to the variations in immunostaining intensity (bouton size and frequency of occurrence) were investigated. The largest boutons were observed in the beta nucleus. Intermediate sized boutons were observed in the dorsomedial cell column, dorsal cap and the dorsal fold of the dorsal accessory olive. The smallest boutons were present in the remaining regions of the inferior olive, including the principal olive, the rostral lamella of the medial accessory olive, and the ventral fold of the dorsal accessory olive. The medial region of the dorsal accessory olive ventral fold contained a higher density of GABAergic boutons than other regions. GABAergic bouton size and innervation density therefore largely accounted for the variations in GAD immunostaining intensity. This study provides a map of the rat inferior olive based on the distribution of GABAergic nerve terminals, and may serve as a basis for characterizing different GABAergic afferent systems in the inferior olive.
通过谷氨酸脱羧酶（GAD）免疫细胞化学方法，在大鼠下橄榄核的所有区域均检测到了推测以γ-氨基丁酸作为神经递质的终扣（GABA能终扣）。这些终扣的显著高浓度使得橄榄核亚核边界清晰可见。在核复合体内部观察到了GAD免疫染色强度的区域差异，并通过视觉和光度测量进行了分级。区域染色差异在很大程度上遵循了由攀缘纤维投射地形图所划定的亚核边界和橄榄带区室。一些亚核按相似的染色强度分组。β核以及背侧副橄榄核腹侧褶的内侧区域免疫染色最强，其次是内侧副橄榄核的亚核c。在背内侧细胞柱、背侧副橄榄核的背侧褶和背帽中观察到较低的染色强度。在内侧副橄榄核的亚核a和b、腹外侧突出部、内侧副橄榄核的嘴侧薄片、主橄榄核以及背侧副橄榄核腹侧褶的外侧部分观察到最低的强度。对导致免疫染色强度变化的因素（终扣大小和出现频率）进行了研究。在β核中观察到最大的终扣。中等大小的终扣见于背内侧细胞柱、背帽和背侧副橄榄核背侧褶。最小的终扣存在于下橄榄核的其余区域，包括主橄榄核、内侧副橄榄核的嘴侧薄片以及背侧副橄榄核腹侧褶。背侧副橄榄核腹侧褶的内侧区域比其他区域含有更高密度的GABA能终扣。因此，GABA能终扣大小和神经支配密度在很大程度上解释了GAD免疫染色强度的差异。本研究基于GABA能神经末梢的分布提供了大鼠下橄榄核的图谱，并可为表征下橄榄核中不同的GABA能传入系统奠定基础。
