Dotti C G, Banker G A
Department of Anatomy, Cell Biology, and Neurobiology, Albany Medical College, New York 12208.
Nature. 1987;330(6145):254-6. doi: 10.1038/330254a0.
Despite the great diversity of shapes exhibited by different classes of nerve cells, nearly all neurons share one feature in that they have a single axon and several dendrites. The two types of processes differ in their morphology, in their rate of growth, in the macromolecular composition of their cytoskeletons and surface membranes, and in their synaptic polarity. When hippocampal neurons are dissociated from the embryonic brain and cultured, they reproducibly establish this basic form with a single axon and several dendrites, despite the absence of any spatially organized environmental cues, and without the need for cell to cell contact. We have cut the axons of young hippocampal neurons within a day of their development: in some cases the initial axon regenerated, but more frequently one of the other processes, which if undisturbed would have become a dendrite, instead became the axon. Frequently the stump of the original axon persisted following the transection and subsequently became a dendrite. Evidently the neuronal processes that first develop in culture have the capacity to form either axons or dendrites. The acquisition of axonal characteristics by one neuronal process apparently inhibits the others from becoming axons, so they subsequently become dendrites.
尽管不同类型的神经细胞呈现出多种多样的形状，但几乎所有神经元都有一个共同特征，即它们有一条单一的轴突和多条树突。这两种突起在形态、生长速度、细胞骨架和表面膜的大分子组成以及突触极性方面都有所不同。当海马神经元从胚胎大脑中分离出来进行培养时，尽管没有任何空间组织化的环境线索，也无需细胞间接触，它们仍能可重复地形成具有一条单一轴突和多条树突的这种基本形态。我们在年轻海马神经元发育一天内切断其轴突：在某些情况下，最初的轴突会再生，但更常见的是，其他突起中的一个，若未受干扰本会成为树突，却反而变成了轴突。通常，原始轴突的残端在横切后会持续存在，随后变成树突。显然，在培养中最先发育的神经元突起有能力形成轴突或树突。一个神经元突起获得轴突特征显然会抑制其他突起变成轴突，所以它们随后就变成了树突。
