Fayyazuddin Amir, Zaheer Mahira A, Hiesinger P Robin, Bellen Hugo J
Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, USA.
PLoS Biol. 2006 Mar;4(3):e63. doi: 10.1371/journal.pbio.0040063. Epub 2006 Feb 28.
Acetylcholine is the major excitatory neurotransmitter in the central nervous system of insects. Mutant analysis of the Dalpha7 nicotinic acetylcholine receptor (nAChR) of Drosophila shows that it is required for the giant fiber-mediated escape behavior. The Dalpha7 protein is enriched in the dendrites of the giant fiber, and electrophysiological analysis of the giant fiber circuit showed that sensory input to the giant fiber is disrupted, as is transmission at an identified cholinergic synapse between the peripherally synapsing interneuron and the dorsal lateral muscle motor neuron. Moreover, we found that gfA1, a mutation identified in a screen for giant fiber defects more than twenty years ago, is an allele of Dalpha7. Therefore, a combination of behavioral, electrophysiological, anatomical, and genetic data indicate an essential role for the Dalpha7 nAChR in giant fiber-mediated escape in Drosophila.
乙酰胆碱是昆虫中枢神经系统中的主要兴奋性神经递质。对果蝇Dalpha7烟碱型乙酰胆碱受体（nAChR）的突变分析表明，它是巨纤维介导的逃避行为所必需的。Dalpha7蛋白在巨纤维的树突中富集，对巨纤维回路的电生理分析表明，传入巨纤维的感觉输入受到破坏，外周突触中间神经元与背外侧肌肉运动神经元之间一个已确定的胆碱能突触的传递也受到破坏。此外，我们发现gfA1是二十多年前在一次巨纤维缺陷筛选中鉴定出的一个突变，它是Dalpha7的一个等位基因。因此，行为学、电生理学、解剖学和遗传学数据的综合表明，Dalpha7 nAChR在果蝇巨纤维介导的逃避中起着至关重要的作用。
