Mrzljak L, Levey A I, Rakic P
Section of Neurobiology, Yale University School of Medicine, New Haven, CT 06511, USA.
Proc Natl Acad Sci U S A. 1996 Jul 9;93(14):7337-40. doi: 10.1073/pnas.93.14.7337.
Visual information in primates is relayed from the dorsal lateral geniculate nucleus to the cerebral cortex by three parallel neuronal channels designated the parvocellular, magnocellular, and interlaminar pathways. Here we report that m2 muscarinic acetylcholine receptor in the macaque monkey visual cortex is selectively associated with synaptic circuits subserving the function of only one of these channels. The m2 receptor protein is enriched both in layer IV axons originating from parvocellular layers of the dorsal lateral geniculate nucleus and in cytochrome oxidase poor interblob compartments in layers II and III, which are linked with the parvocellular pathway. In these compartments, m2 receptors appear to be heteroreceptors, i.e., they are associated predominantly with asymmetric, noncholinergic synapses, suggesting a selective role in the modulation of excitatory neurotransmission through the parvocellular visual channel.
在灵长类动物中，视觉信息通过三条平行的神经元通道从背外侧膝状核传递至大脑皮层，这三条通道分别称为小细胞通路、大细胞通路和层间通路。我们在此报告，猕猴视觉皮层中的M2毒蕈碱型乙酰胆碱受体仅选择性地与服务于这些通道之一功能的突触回路相关联。M2受体蛋白在源自背外侧膝状核小细胞层的IV层轴突以及II层和III层中细胞色素氧化酶含量较低的斑间区均有富集，这些区域与小细胞通路相连。在这些区域中，M2受体似乎是异受体，即它们主要与不对称的、非胆碱能突触相关联，这表明其在通过小细胞视觉通道调节兴奋性神经传递中具有选择性作用。
