Electrophysiological and morphological characterization of identified motor neurons in the Drosophila third instar larva central nervous system
Electrophysiological and morphological characterization of identified motor neurons in the Drosophila third instar larva central nervous system
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DOI：
10.1152/jn.01115.2003
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发表时间：
2004-05-01
影响因子：
2.5
通讯作者：
Griffith, LC
中科院分区：
文献类型：
--
作者：
Choi, JC;Park, D;Griffith, LC
我们已经使用染料填充和电生理记录，以确定和表征一组运动神经元在三龄幼虫腹神经节。这簇神经元在位置上与研究充分的胚胎RP神经元相似。幼虫背内侧神经元的染料填充表明，集群内的单个神经元可以通过观察它们的肌肉靶点和终扣形态来重复识别。这五个神经元的终末靶点是体壁肌肉6/7、1、14和30以及节间神经（ISN）终末肌肉（1、2、3、4、9、10、19、20）。除了ISN神经元具有I型终末外，所有细胞都显示Ib型终末。这些神经元中的两个似乎是相同的胚胎RP 3和aCC细胞，其定义的最近端和远端的神经支配内的半节。幼虫背内侧集群中的其他神经元的目标不对应于RP集群中的神经元的胚胎目标，这表明在早期幼虫阶段的电路重新布线。对这5个神经元的电流钳电生理研究表明，与Ib型神经元相比，I型神经元的第一个锋电位的出现延迟较长。在电流和电压钳中的遗传、生物物理和药理学研究表明，这种延迟是由电流失活的动力学和电压敏感性控制的，该电流的性质表明它可能是Shal IA电流。遗传鉴定和全细胞记录的结合使我们能够在完整的系统中直接探索神经和运动行为的细胞基质。
We have used dye fills and electrophysiological recordings to identify and characterize a cluster of motor neurons in the third instar larval ventral ganglion. This cluster of neurons is similar in position to the well-studied embryonic RP neurons. Dye fills of larval dorsomedial neurons demonstrate that individual neurons within the cluster can be reproducibly identified by observing their muscle targets and bouton morphology. The terminal targets of these five neurons are body wall muscles 6/7, 1, 14, and 30 and the intersegmental nerve (ISN) terminal muscles (1, 2, 3, 4, 9, 10, 19, 20). All cells except the ISN neuron, which has a type Is ending, display type Ib boutons. Two of these neurons appear to be identical to the embryonic RP3 and aCC cells, which define the most proximal and distal innervations within a hemisegment. The targets of the other neurons in the larval dorsomedial cluster do not correspond to embryonic targets of the neurons in the RP cluster, suggesting rewiring of this circuit during early larval stages. Electrophysiological studies of the five neurons in current clamp revealed that type Is neurons have a longer delay in the appearance of the first spike compared with type Ib neurons. Genetic, biophysical, and pharmacological studies in current and voltage clamp show this delay is controlled by the kinetics and voltage sensitivity of inactivation of a current whose properties suggest that it may be the Shal I A current. The combination of genetic identification and whole cell recording allows us to directly explore the cellular substrates of neural and locomotor behavior in an intact system.