Woodward W R, Blank N K, Seil F J
Brain Res. 1982 Jun 10;241(2):323-7. doi: 10.1016/0006-8993(82)91070-8.
The finding of the acetylcholine synthetic enzyme, choline acetyltransferase, has been reported in mouse cerebellar cultures, and it has been used as an index of neuronal survival and maturation. These results are curious in light of immunocytochemical studies which show that this enzyme is localized within mossy fiber terminals in glomerular structures of the cerebellar cortex. Since most mossy fibers are of extracerebellar origin, a significant population of mossy fiber terminals would not be expected to be present in cerebellar cultures. The origin of this acetylcholine synthetic activity has been examined in mouse cerebellar cultures. Two groups of explants, one with and the other without incorporated dorsal pontine tissue, were cultivated. Only cultures that included pons showed well developed glomerular structures with mossy fiber rosettes. Homogenates of the cultures were assayed for their ability to synthesize acetylcholine, and the synthesis was shown to be due to choline acetyltransferase by use of the specific inhibitor, (naphthylvinyl)pyridine. Cultures lacking dorsal pontine tissue had only low levels of enzyme activity, whereas those which included pons had 20-60 times greater synthetic activity. These results indicate that the choline acetyltransferase activity arises from pontine tissue in cerebellar cultures and are consistent with mossy fibers being the source of this enzyme.
在小鼠小脑培养物中已报道发现了乙酰胆碱合成酶——胆碱乙酰转移酶，它已被用作神经元存活和成熟的指标。鉴于免疫细胞化学研究表明该酶定位于小脑皮质小球状结构中的苔藓纤维终末内，这些结果令人好奇。由于大多数苔藓纤维起源于小脑外，因此在小脑培养物中预计不会存在大量的苔藓纤维终末。已在小鼠小脑培养物中研究了这种乙酰胆碱合成活性的起源。培养了两组外植体，一组包含脑桥背侧组织，另一组不包含。只有包含脑桥的培养物显示出具有苔藓纤维玫瑰花结的发育良好的小球状结构。对培养物的匀浆进行了乙酰胆碱合成能力的测定，并且通过使用特异性抑制剂（萘基乙烯基）吡啶表明该合成是由胆碱乙酰转移酶引起的。缺乏脑桥背侧组织的培养物只有低水平的酶活性，而包含脑桥的培养物的合成活性则高20 - 60倍。这些结果表明胆碱乙酰转移酶活性源自小脑培养物中的脑桥组织，并且与苔藓纤维是该酶的来源一致。
