Connor J A
Proc Natl Acad Sci U S A. 1986 Aug;83(16):6179-83. doi: 10.1073/pnas.83.16.6179.
Intracellular free calcium levels have been measured in cultured central nervous system (CNS) cells by using the fluorescent indicator fura-2 and digital imaging techniques. Cells were plated from rat embryo diencephalon (embryonic day 17 or 18), with nearly all of the cells surviving dissociation having undergone final mitosis within the previous 24 hr. The initially spherical cells were observed within the first 24 hr in culture when they were extending processes but had not established a network of fibers that would prevent the identification of the origin of a given fiber. Cells that were rapidly extending showed high Ca2+ levels in the regions of growth. Where processes had just emerged from the soma or where growth was proceeding from more than one pole, Ca2+ levels were uniform and estimated levels of 500 nM were commonly seen. In active growth cones distant from the soma, Ca2+ levels exceeded 200 nM, whereas the soma levels were in the 60-80 nM range. Nonextended and extended cells that had stalled had uniform Ca2+ levels in the range of 30-70 nM. The results show that high Ca2+ levels are at least a correlate of extension in CNS cells and that under some conditions the region of high calcium can be localized to a small part of the cell.
利用荧光指示剂fura-2和数字成像技术，对培养的中枢神经系统（CNS）细胞内的游离钙水平进行了测量。细胞取自大鼠胚胎间脑（胚胎第17或18天），几乎所有在解离后存活的细胞都在之前的24小时内完成了最后一次有丝分裂。最初呈球形的细胞在培养的最初24小时内被观察到，此时它们正在伸出突起，但尚未形成会妨碍确定某一特定纤维起源的纤维网络。快速伸出突起的细胞在生长区域显示出高钙水平。在突起刚从胞体伸出的部位或从多个极点进行生长的部位，钙水平是均匀的，通常可见估计为500 nM的水平。在远离胞体的活跃生长锥中，钙水平超过200 nM，而胞体水平在60 - 80 nM范围内。未伸出突起和伸出突起但停止生长的细胞，其钙水平均匀，在30 - 70 nM范围内。结果表明，高钙水平至少与中枢神经系统细胞的伸出有关，并且在某些情况下，高钙区域可以定位到细胞的一小部分。
