Quinn M R, Cagan R H
J Neurochem. 1980 Sep;35(3):583-90. doi: 10.1111/j.1471-4159.1980.tb03694.x.
The olfactory bulbs in the CNS contain reciprocal dendrodendritic synapses between the granule cells and the secondary dendrites of mitral cells. Based on pharmacologic and electrophysiologic evidence, these synapses are believed to utilize GABA as an inhibitory neurotransmitter. A dendrodendritic synaptosomal fraction has been isolated from rat olfactory bulbs. The upper portion (PB) of the crude nuclear pellet contains 30-40% of the GAD (glutamate decarboxylase) activity of the olfactory bulb homogenate. When PB is purified on a discontinuous sucrose density gradient, 78-85% of the GAD activity is localized to the region containing the dendrodendritic synaptosomes, which were identified by transmission electron microscopy. The presence of a substantial proportion of GAD, the enzyme that catalyzes synthesis of GABA, in the DDS provides neurochemical support for the hypothesis that GABA functions at the reciprocal dendrodendritic synapses in the olfactory bulb.
中枢神经系统中的嗅球在颗粒细胞和二尖瓣细胞的二级树突之间含有相互的树突-树突突触。基于药理学和电生理学证据，这些突触被认为利用GABA作为抑制性神经递质。已从大鼠嗅球中分离出一种树突-树突突触体组分。粗核沉淀物的上部（PB）含有嗅球匀浆中30-40%的谷氨酸脱羧酶（GAD）活性。当PB在不连续蔗糖密度梯度上纯化时，78-85%的GAD活性定位于含有树突-树突突触体的区域，这些突触体通过透射电子显微镜鉴定。在树突-树突突触体中存在大量催化GABA合成的GAD，为GABA在嗅球中相互的树突-树突突触处发挥作用这一假说提供了神经化学支持。
