Polleux F, Morrow T, Ghosh A
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185, USA.
Nature. 2000 Apr 6;404(6778):567-73. doi: 10.1038/35007001.
The apical dendrites of pyramidal neurons integrate inputs from various cortical layers and are central to information processing. Here we show that the growth of apical dendrites towards the pial surface is regulated by a diffusible chemoattractant present at high levels near the marginal zone. A major component of this signal is semaphorin 3A (Sema3A), which was previously characterized as a chemorepellant for cortical axons. Soluble guanylate cyclase is asymmetrically localized to the developing apical dendrite, and is required for the chemoattractive effect of Sema3A. Thus the asymmetric localization of soluble guanylate cyclase confers distinct Sema3A responses to axons and dendrites. These observations reveal a mechanism by which a single chemotropic signal can pattern both axons and dendrites during development.
锥体神经元的顶端树突整合来自不同皮质层的输入，是信息处理的核心。我们在此表明，顶端树突向软脑膜表面的生长受边缘区附近高水平存在的一种可扩散化学引诱剂调节。该信号的一个主要成分是信号素3A（Sema3A），它先前被表征为皮质轴突的化学排斥剂。可溶性鸟苷酸环化酶不对称地定位于发育中的顶端树突，并且是Sema3A化学吸引作用所必需的。因此，可溶性鸟苷酸环化酶的不对称定位赋予轴突和树突对Sema3A的不同反应。这些观察结果揭示了一种机制，通过该机制，单一的化学趋向性信号可以在发育过程中对轴突和树突进行模式化。
