Houben M P, Lankhorst A J, van Dalen J J, Veldman H, Joosten E A, Hamers F P, Gispen W H, Schrama L H
Department of Medical Pharmacology, Rudolf Magnus Institute for Neurosciences, University Medical Center, University of Utrecht, Utrecht, The Netherlands.
J Neurosci Res. 2000 Mar 15;59(6):750-9. doi: 10.1002/(SICI)1097-4547(20000315)59:6<750::AID-JNR7>3.0.CO;2-B.
RC3 (neurogranin; BICKS) is a neuron-specific calmodulin-binding protein kinase C substrate. Thus far, immunohistochemical studies on the localization of RC3 revealed its presence in all neuronal phenotypes, which were restricted to specific areas in the neostriatum, the neocortex, and the hippocampus. RC3 was mostly found in cell bodies and dendrites, with some infrequent presence in axonal profiles, i.e. in the internal capsule. Until now, RC3 expression was reported to be absent in the adult rat spinal cord. RC3 might, however, act as an intermediate of protein kinase C-mediated signaling pathways during synaptic development and plasticity. We hypothesized a role for this 78-amino-acid protein in dendritic plasticity occurring after spinal cord injury. To our surprise, an immunohistological analysis of the uninjured adult rat spinal cord revealed the presence of RC3-positive cell bodies and dendrites in specific regions in the gray matter. Interestingly, axon-containing structures, such as the dorsal and ventral corticospinal tract, were also found to be RC3-positive. This axonal labeling was confirmed by preembedding electron microscopy. In conclusion, we demonstrate here that RC3 is present in the adult rat spinal cord in pre- and postsynaptic structures.
RC3（神经颗粒素；BICKS）是一种神经元特异性钙调蛋白结合蛋白激酶C底物。迄今为止，关于RC3定位的免疫组织化学研究表明，它存在于所有神经元表型中，这些表型局限于新纹状体、新皮质和海马体的特定区域。RC3主要存在于细胞体和树突中，在轴突轮廓中偶尔出现，即在大脑内囊中。到目前为止，据报道成年大鼠脊髓中不存在RC3表达。然而，RC3可能在突触发育和可塑性过程中作为蛋白激酶C介导的信号通路的中间体。我们推测这种78个氨基酸的蛋白质在脊髓损伤后发生的树突可塑性中起作用。令我们惊讶的是，对未受伤的成年大鼠脊髓进行的免疫组织学分析显示，灰质的特定区域存在RC3阳性细胞体和树突。有趣的是，含有轴突的结构，如背侧和腹侧皮质脊髓束，也被发现为RC3阳性。这种轴突标记通过包埋前电子显微镜得到证实。总之，我们在此证明RC3存在于成年大鼠脊髓的突触前和突触后结构中。
