Growth cone responses to growth and chemotropic factors.
Growth cone responses to growth and chemotropic factors.
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生长锥对生长和趋化因子的反应。
DOI：
10.1111/j.1460-9568.2008.06327.x
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Pfenninger,KarlH
中科院分区：
文献类型：
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作者：
Sanford,StaciD;Gatlin,JesseC;Hokfelt,Tomas;Pfenninger,KarlH
在神经系统发育期间，轴突在影响生长速度和方向的许多引导线索的影响下到达其目标区域。这份报告解决了一个悬而未决的问题，即增长速度和转向反应（吸引力，排斥力）是否以及在多大程度上是相互依赖的。我们暴露个别生长锥的胎鼠背根神经节神经元在文化不对称的梯度7个不同的因素，并记录其生长速度和旋转角度。生长锥表现出不同的模式的转折和增长的反应。例如，肝细胞生长因子（HGF），胰岛素样生长因子-1（IGF-1）和凝血酶都促进生长，但HGF是一种强大的引诱剂，凝血酶是一种有效的驱避剂，IGF-1不会引起转向。甘丙肽和神经肽Y也影响生长和/或转向差异。最后，培养基中的神经生长因子不仅抑制对HGF的转向反应，而且还将HGF和IGF-1的生长促进转化为抑制。总体而言，我们的研究表明：（i）转动和前进是独立调节的，除了强烈的吸引或排斥反应通常伴随着生长促进;（ii）不对称的生长因子应用本身并不引起吸引;（iii）这两个参数的调节可能通过单一受体发生;（iv）组合生长因子的作用可能不是相加的，而是抑制性的。
During nervous system development axons reach their target areas under the influence of numerous guidance cues that affect rate and direction of growth. This report addresses the unsettled question of whether and to what extent growth velocity and turning responses (attraction, repulsion) are interdependent. We exposed individual growth cones of fetal rat dorsal root ganglion neurons in culture asymmetrically to gradients of seven different factors and recorded their growth rates and turning angles. Growth cones exhibited divergent patterns of turning and growth responses. For example, hepatocyte growth factor (HGF), insulin‐like growth factor‐1 (IGF‐1) and thrombin all promoted growth, but HGF was a powerful attractant, thrombin a potent repellent and IGF‐1 did not elicit turning. Galanin and neuropeptide Y also affected growth and/or turning differentially. Finally, nerve growth factor in the culture medium not only inhibited the turning responses to HGF, but also converted growth promotion of HGF and IGF‐1 into inhibition. Overall, our studies indicate that: (i) turning and advance are regulated independently, except that strong attractive or repulsive responses generally are accompanied by growth promotion; (ii) asymmetric growth factor applicationper sedoes not elicit attraction; (iii) regulation of the two parameters may occur through a single receptor; and (iv) the effects of combined growth factors may not be additive and can be inhibitory.