Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269-3156, USA.
J Comp Neurol. 2010 Sep 1;518(17):3439-63. doi: 10.1002/cne.22390.
It has been proposed that gamma-protocadherins (Pcdh-gammas) are involved in the establishment of specific patterns of neuronal connectivity. Contrary to the other Pcdh-gammas, which are expressed in the embryo, Pcdh-gammaC5 is expressed postnatally in the brain, coinciding with the peak of synaptogenesis. We have developed an antibody specific for Pcdh-gammaC5 to study the expression and localization of Pcdh-gammaC5 in brain. Pcdh-gammaC5 is highly expressed in the olfactory bulb, corpus striatum, dentate gyrus, CA1 region of the hippocampus, layers I and II of the cerebral cortex, and molecular layer of the cerebellum. Pcdh-gammaC5 is expressed in both neurons and astrocytes. In hippocampal neuronal cultures, and in the absence of astrocytes, a significant percentage of synapses, more GABAergic than glutamatergic, have associated Pcdh-gammaC5 clusters. Some GABAergic axons show Pcdh-gammaC5 in the majority of their synapses. Nevertheless, many Pcdh-gammaC5 clusters are not associated with synapses. In the brain, significant numbers of Pcdh-gammaC5 clusters are located at contact points between neurons and astrocytes. Electron microscopic immunocytochemistry of the rat brain shows that 1) Pcdh-gammaC5 is present in some GABAergic and glutamatergic synapses both pre- and postsynaptically; 2) Pcdh-gammaC5 is also extrasynaptically localized in membranes and in cytoplasmic organelles of neurons and astrocytes; and 3) Pcdh-gammaC5 is also localized in perisynaptic astrocyte processes. The results support the notions that 1) Pcdh-gammaC5 plays a role in synaptic specificity and/or synaptic maturation and 2) Pcdh-gammaC5 is involved in neuron-neuron synaptic interactions and in neuron-astrocyte interactions, including perisynaptic neuron-astrocyte interactions.
已经有人提出，γ-原钙黏蛋白（Pcdh-gammas）参与了特定神经元连接模式的建立。与其他在胚胎中表达的 Pcdh-gammas 不同，Pcdh-gammaC5 在大脑中出生后表达，与突触发生的高峰期相吻合。我们开发了一种针对 Pcdh-gammaC5 的抗体，用于研究 Pcdh-gammaC5 在大脑中的表达和定位。Pcdh-gammaC5 在嗅球、纹状体、齿状回、海马 CA1 区、大脑皮层 I 和 II 层以及小脑分子层高度表达。Pcdh-gammaC5 表达于神经元和星形胶质细胞中。在海马神经元培养物中，在没有星形胶质细胞的情况下，相当比例的突触，更多的 GABA 能而不是谷氨酸能，与 Pcdh-gammaC5 簇相关联。一些 GABA 能轴突在其大多数突触中显示 Pcdh-gammaC5。然而，许多 Pcdh-gammaC5 簇与突触无关。在大脑中，大量的 Pcdh-gammaC5 簇位于神经元和星形胶质细胞的接触点。大鼠脑的电镜免疫细胞化学显示：1）Pcdh-gammaC5 存在于一些 GABA 能和谷氨酸能突触的前突触和后突触中；2）Pcdh-gammaC5 也在神经元和星形胶质细胞的膜和细胞质细胞器中存在于突触外；3）Pcdh-gammaC5 也定位于突触旁星形胶质细胞突起中。这些结果支持以下观点：1）Pcdh-gammaC5 在突触特异性和/或突触成熟中发挥作用；2）Pcdh-gammaC5 参与神经元-神经元突触相互作用以及神经元-星形胶质细胞相互作用，包括突触旁神经元-星形胶质细胞相互作用。
