Hill A A, Edwards D H, Murphey R K
Department of Biology, Morrill Science Center (South), University of Massachusetts at Amherst, 01003-35825, USA.
J Comput Neurosci. 1994 Aug;1(3):239-54. doi: 10.1007/BF00961736.
The way in which the dimensions of neurons change during postembryonic development has important effects on their electrotonic structures. Theoretically, only one mode of growth can conserve the electrotonic structures of growing neurons without employing changes in membrane electrical properties. If the dendritic diameters of a neuron increase as the square of the increase in dendritic lengths, then the neuron's electrotonic structure is conserved. We call this special mode of allometric growth "isoelectrotonic growth." In this study we compared the developmental changes in morphology of two identified invertebrate neurons with theoretical growth curves. We found that a cricket neuron, MGI, grows isoelectrotonically and thereby preserves its electrotonic properties. In contrast, the crayfish neuron, LG, grows in nearly isometric manner resulting in an increase in its electrotonic length.
神经元在胚胎后期发育过程中尺寸变化的方式对其电紧张结构具有重要影响。从理论上讲，只有一种生长模式能够在不改变膜电特性的情况下保持生长中神经元的电紧张结构。如果神经元的树突直径随着树突长度增加的平方而增加，那么该神经元的电紧张结构就得以保持。我们将这种特殊的异速生长模式称为“等电紧张生长”。在本研究中，我们将两个已识别的无脊椎动物神经元的形态发育变化与理论生长曲线进行了比较。我们发现，蟋蟀神经元MGI以等电紧张方式生长，从而保持其电紧张特性。相比之下，小龙虾神经元LG以近乎等距的方式生长，导致其电紧张长度增加。
