Layer P G
Max-Planck-Institut für Entwicklungsbiologie, Tübingen, FRG.
Bioessays. 1990 Sep;12(9):415-20. doi: 10.1002/bies.950120904.
The role of acetylcholinesterase (AChE) in neurotransmission is well known. But long before synapses are formed in vertebrates, AChE is expressed in young postmitotic neuroblasts that are about to extend the first long tracts. AChE histochemistry can thus be used to map primary steps of brain differentiation. Preceding and possibly inducing AChE in avian brains, the closely related butyrylcholinesterase (BChE) spatially foreshadows AChE-positive cell areas and the course of their axons. In particular, before spinal motor axons grow, their corresponding rostral sclerotomes and myotomes express BChE, and both their neuronal source and myotomal target cells express AChE. Since axon growth has been found inhibited by acetylcholine, it is postulated that both cholinesterases can attract neurite growth cones by neutralizing the inhibitor. Thus, the early expression of both cholinesterases that is at least partially independent from classical cholinergic synaptogenesis, sheds new light on the developmental and medical significance of these enzymes.
乙酰胆碱酯酶（AChE）在神经传递中的作用众所周知。但早在脊椎动物形成突触之前，AChE就在即将延伸出第一批长神经束的年轻有丝分裂后神经母细胞中表达。因此，AChE组织化学可用于绘制脑分化的初级步骤。在鸟类大脑中，与AChE密切相关的丁酰胆碱酯酶（BChE）在空间上预示着AChE阳性细胞区域及其轴突的走向，并且可能先于AChE出现并诱导其产生。特别是，在脊髓运动轴突生长之前，其相应的头侧体节和肌节表达BChE，其神经元来源和肌节靶细胞均表达AChE。由于已发现轴突生长受到乙酰胆碱的抑制，因此推测这两种胆碱酯酶都可以通过中和抑制剂来吸引神经突生长锥。因此，这两种胆碱酯酶的早期表达至少部分独立于经典胆碱能突触形成，为这些酶的发育和医学意义提供了新的线索。
