Kharazia V N, Weinberg R J
Department of Cell Biology and Anatomy, University of North Carolina, Chapel Hill 27599, USA.
Neurosci Lett. 1997 Nov 28;238(1-2):41-4. doi: 10.1016/s0304-3940(97)00846-x.
We performed an electron microscopic study in layers II-III of S-1 in rats, using postembedding immunogold histochemistry to compare the synaptic distribution of N-methyl D-aspartate (NMDA) receptors (assessed with an antibody for the NMDAR1 subunit) with that of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors (assessed with an antibody for the GluR2/3 subunit). Labeling for each receptor was concentrated at active zones of asymmetric synapses. Analysis of the tangential position of gold particles along the postsynaptic active zone revealed that NMDA receptors were at highest concentration in the middle of the synaptic apposition, whereas AMPA receptors were concentrated in an annulus away from its center. These data support the view that the two types of receptors are anchored by distinct subsynaptic assemblies, and raise the possibility of independent synaptic microdomains.
我们利用包埋后免疫金组织化学技术，对大鼠S-1区II-III层进行了电子显微镜研究，以比较N-甲基-D-天冬氨酸（NMDA）受体（用针对NMDAR1亚基的抗体评估）与α-氨基-3-羟基-5-甲基异恶唑-4-丙酸（AMPA）受体（用针对GluR2/3亚基的抗体评估）的突触分布。每种受体的标记都集中在不对称突触的活性区。对沿突触后活性区金颗粒切线位置的分析表明，NMDA受体在突触并置的中间浓度最高，而AMPA受体则集中在远离其中心的环形区域。这些数据支持了两种类型的受体由不同的突触下组件锚定的观点，并提出了独立突触微域的可能性。
