Viennot F, Foucaud B, Gombos G
Centre de Neurochimie du CNRS, Strasbourg, France.
Neurochem Res. 1992 Jul;17(7):683-6. doi: 10.1007/BF00968005.
In the internal granular layer of the cerebellar cortex the polysynaptic complexes called glomeruli consist mainly of homogeneous populations of glutamatergic and GABAergic synapses, both located on granule cell dendrites. A subcellular fraction enriched in glomeruli was prepared from rat cerebellum, and the distribution of GABAA and of benzodiazepine binding sites between membranes derived from this fraction (fraction G) and from a total cerebellar homogenate (fraction T) was studied. The benzodiazepine and GABA binding sites were measured by the binding of agonists [3H]flunitrazepam and [3H]muscimol, respectively. The results indicate that both binding sites are present, but only slightly enriched, in the glomerular synapses. We found a muscimol/flunitrazepam binding site ratio of two, which is consistent with the enrichment of muscimol binding sites in the granular layer shown by both autoradiographic with radioactive glutamatergic ligands and in situ hybridization experiments respectively.
在小脑皮质的内颗粒层中，被称为小球的多突触复合体主要由位于颗粒细胞树突上的谷氨酸能和γ-氨基丁酸能突触的同质群体组成。从小鼠小脑中制备了富含小球的亚细胞组分，并研究了γ-氨基丁酸A（GABAA）和苯二氮䓬结合位点在该组分（组分G）和全小脑匀浆（组分T）衍生的膜之间的分布。苯二氮䓬和γ-氨基丁酸结合位点分别通过激动剂[³H]氟硝西泮和[³H]蝇蕈醇的结合来测定。结果表明，两种结合位点均存在于小球突触中，但仅略有富集。我们发现蝇蕈醇/氟硝西泮结合位点的比例为2，这与分别用放射性谷氨酸能配体进行放射自显影和原位杂交实验所显示的颗粒层中蝇蕈醇结合位点的富集情况一致。
