Molecular underpinnings of motor pattern generation: differential targeting of shal and shaker in the pyloric motor system
Molecular underpinnings of motor pattern generation: differential targeting of shal and shaker in the pyloric motor system
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DOI：
10.1523/jneurosci.20-17-06619.2000
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发表时间：
2000-09-01
影响因子：
5.3
通讯作者：
Harris-Warrick, RM
中科院分区：
文献类型：
--
作者：
Baro, DJ;Ayali, A;Harris-Warrick, RM
由幽门回路在多刺龙虾，Panulirus interruptus的口胃神经节中产生的模式化活动不仅来自14个组成神经元之间的突触连接，而且来自神经元内在特性的差异。据推测，表达的离子通道的补充和分布的差异赋予这些神经元许多独特的属性。每种幽门细胞类型都具有独特的、可调节的瞬时钾电流或A电流（I-A），这有助于确定网络的输出。在该系统中，两个基因编码A通道，shaker和shal。我们研究了这一假设，即细胞特异性差异的shaker和shal通道分布有助于幽门神经元之间的多样性。我们发现了细胞中通道的刻板分布，使得每种通道类型可以对细胞的放电特性的不同方面做出贡献。Shal主要存在于体树突隔室中，在其中它影响振荡行为和尖峰频率。振动器通道专门定位于远端轴突隔室的膜，并且最有可能影响远端尖峰传播。没有一个通道可检测地插入轴突膜的前轴突或近端部分。两种通道类型都靶向神经肌肉接头处的突触接触。我们的结论是，不同的目标shaker和shal到不同的隔间是保守的所有幽门神经元和通道最有可能subserve不同的功能，在神经元。
The patterned activity generated by the pyloric circuit in the stomatogastric ganglion of the spiny lobster, Panulirus interruptus, results not only from the synaptic connectivity between the 14 component neurons but also from differences in the intrinsic properties of the neurons. Presumably, differences in the complement and distribution of expressed ion channels endow these neurons with many of their distinct attributes. Each pyloric cell type possesses a unique, modulatable transient potassium current, or A-current (I-A), that is instrumental in determining the output of the network. Two genes encode A-channels in this system, shaker and shal. We examined the hypothesis that cell-specific differences in shaker and shal channel distribution contribute to diversity among pyloric neurons. We found a stereotypic distribution of channels in the cells, such that each channel type could contribute to different aspects of the firing properties of a cell. Shal is predominantly found in the somatodendritic compartment in which it influences oscillatory behavior and spike frequency. Shaker channels are exclusively localized to the membranes of the distal axonal compartments and most likely affect distal spike propagation. Neither channel is detectably inserted into the preaxonal or proximal portions of the axonal membrane. Both channel types are targeted to synaptic contacts at the neuromuscular junction. We conclude that the differential targeting of shaker and shal to different compartments is conserved among all the pyloric neurons and that the channels most likely subserve different functions in the neuron.