Division of Brain Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan.
J Chem Neuroanat. 2010 Oct;40(2):112-22. doi: 10.1016/j.jchemneu.2010.05.001. Epub 2010 May 10.
The extracellular matrix (ECM) plays important roles in the development and plasticity of the central nervous system, and it has been shown that it regulates reorganization of the neuronal network. We have found that expression of OCC1, testican-1, testican-2, testican-3, SPARC and SC1 mRNAs, which encode members of the OCC1-related family of ECM proteins, exhibits distinct activity-dependent expression patterns in the adult macaque visual cortex. This finding suggests that OCC1-related proteins play crucial roles in the visual processing pathway. In the present study, we examined mRNA expression patterns of OCC1-related genes in the dorsal lateral geniculate nucleus (dLGN) of macaques. The mRNAs of testican-1 and testican-2 were strongly expressed in both excitatory projection neurons and GABAergic interneurons in the dLGN. Expression of testican-3 mRNA, which is predominantly observed in GABAergic interneurons in the cortex, was restricted to excitatory projection neurons in the dLGN. SPARC mRNA was strongly, and exclusively, expressed in glial cells in the dLGN. Interestingly, neuronal SC1 mRNA expression was abundantly observed in intercalated, koniocellular layers of the dLGN, while it was preferentially observed in blob regions of the primary visual area that receives color coding K-pathway projection from dLGN koniocellular layers, suggesting a pathway preference of expression. Finally, monocular inactivation experiments demonstrated that expression of testican-1, testican-2 and testican-3 mRNAs in the dLGN is dependent on sensory activity. Given their differential expression patterns and activity dependence, products of OCC1-related genes may modulate visual processing and plasticity at the level of the dLGN and the visual cortex.
细胞外基质（ECM）在中枢神经系统的发育和可塑性中发挥重要作用，并且已经表明它调节神经元网络的重组。我们发现，OCC1、testican-1、testican-2、testican-3、SPARC 和 SC1 mRNA 的表达，这些基因编码 ECM 蛋白的 OCC1 相关家族成员，在成年猕猴视觉皮层中表现出明显的依赖于活动的表达模式。这一发现表明 OCC1 相关蛋白在视觉处理途径中发挥着关键作用。在本研究中，我们检查了 OCC1 相关基因在猕猴背外侧膝状体核（dLGN）中的 mRNA 表达模式。testican-1 和 testican-2 的 mRNA 在 dLGN 中的兴奋性投射神经元和 GABA 能中间神经元中均强烈表达。testican-3 mRNA 的表达，主要在皮层中的 GABA 能中间神经元中观察到，局限于 dLGN 中的兴奋性投射神经元。SPARC mRNA 在 dLGN 中的神经胶质细胞中强烈而独特地表达。有趣的是，神经元 SC1 mRNA 的表达在 dLGN 的中间层和 koniocellular 层中大量观察到，而在接收来自 dLGN koniocellular 层的颜色编码 K 途径投射的初级视觉区域的blob 区域中优先观察到，这表明表达具有通路偏好性。最后，单眼失活实验表明，dLGN 中 testican-1、testican-2 和 testican-3 mRNA 的表达依赖于感觉活动。鉴于它们的差异表达模式和活动依赖性，OCC1 相关基因的产物可能在膝状体核和视觉皮层水平上调节视觉处理和可塑性。
