Gundersen R W, Barrett J N
Science. 1979 Nov 30;206(4422):1079-80. doi: 10.1126/science.493992.
Micropipettes containing 2 to 50 biological units of beta growth factor (NGF) were placed near growing axons of chick dorsal-root ganglion neurons in tissue culture. The axons turned and grew toward the NGF source within 21 minutes. This turning response to elevated concentrations of NGF appears to represent chemotactic guidance rather than a general enhancement of growth rate.
将含有2至50个生物单位β生长因子（神经生长因子，NGF）的微量移液器放置在组织培养中鸡背根神经节神经元生长轴突附近。轴突在21分钟内转向并朝着NGF源生长。这种对升高浓度的NGF的转向反应似乎代表趋化性引导，而不是生长速率的普遍提高。
