Ouyang Y, Martone M E, Deerinck T J, Airey J A, Sutko J L, Ellisman M H
Department of Neurosciences, University of California at San Diego, School of Medicine, La Jolla 92093-0608, USA.
Brain Res. 1997 Nov 14;775(1-2):52-62. doi: 10.1016/s0006-8993(97)00840-8.
The distribution of ryanodine receptor (RyR) isoforms was examined using isoform-specific monoclonal antibodies in the developing chicken brain, from E18 through adulthood, using light and electron microscopic immunocytochemistry. Monoclonal antibody 110F is specific for the alpha-skeletal muscle form of RyR, while monoclonal antibody 110E recognizes both the beta-skeletal muscle and cardiac isoforms, but does not distinguish between the two. Significant differences in the distribution of the alpha- and beta/cardiac forms were observed. Labeling for the alpha-form was restricted to cerebellar Purkinje neurons while the beta/cardiac form was observed in neurons throughout the brain. A major finding was the presence of labeling for the beta/cardiac in presynaptic terminals of the parallel fibers in the molecular layer and the mossy fiber terminals in the granular layer glomeruli in late development and during adulthood. Labeling for the beta/cardiac, but not the alpha-form, underwent a major redistribution in the cerebellum during the course of development. At 1 day of age, beta/cardiac labeling was present mainly in Purkinje neurons. From 1 day to 4 weeks, immunolabeling for the beta/cardiac form gradually disappeared from Purkinje neurons, but increased in granule cells. Within the molecular layer, the labeling pattern changed from being primarily within Purkinje dendrites to a more diffuse pattern. Electron microscopic examination of the cerebellar molecular layer of 2-week-old chicks revealed that beta/cardiac-labeling was mainly present in the axons and presynaptic processes of the parallel fibers. No developmental changes were observed in other brain regions. This study represents the first demonstration of ryanodine receptor immunoreactivity in presynaptic boutons and suggests that the ryanodine receptor may modulate neurotransmitter release through local regulation of intracellular calcium in the parallel fiber synapse.
利用亚型特异性单克隆抗体，通过光镜和电镜免疫细胞化学技术，研究了从胚胎第18天到成年期发育中的鸡脑内兰尼碱受体（RyR）亚型的分布情况。单克隆抗体110F对RyR的α-骨骼肌型具有特异性，而单克隆抗体110E可识别β-骨骼肌型和心脏型两种亚型，但无法区分二者。观察到α型和β/心脏型分布存在显著差异。α型的标记仅限于小脑浦肯野神经元，而β/心脏型在整个大脑的神经元中均有观察到。一个主要发现是，在发育后期和成年期，分子层平行纤维的突触前终末以及颗粒层肾小球内的苔藓纤维终末中存在β/心脏型的标记。在发育过程中，小脑内β/心脏型（而非α型）的标记发生了主要的重新分布。在出生后1天，β/心脏型标记主要存在于浦肯野神经元中。从1天到4周，浦肯野神经元中β/心脏型的免疫标记逐渐消失，但在颗粒细胞中增加。在分子层内，标记模式从主要在浦肯野树突内变为更弥散的模式。对2周龄雏鸡小脑分子层的电镜检查显示，β/心脏型标记主要存在于平行纤维的轴突和突触前过程中。在其他脑区未观察到发育变化。本研究首次证明了兰尼碱受体在突触前终扣中的免疫反应性，并表明兰尼碱受体可能通过对平行纤维突触内细胞内钙的局部调节来调节神经递质释放。
