Activity-dependent regulation of the subcellular localization of neuronal calcium sensor-1 in the avian cochlear nucleus.
Activity-dependent regulation of the subcellular localization of neuronal calcium sensor-1 in the avian cochlear nucleus.
复制标题
禽类耳蜗核中神经元钙传感器-1 亚细胞定位的活动依赖性调节。
DOI：
10.1016/s0306-4522(02)00928-4
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发表时间：
2003
期刊：
影响因子：
3.3
通讯作者：
Hyson,RL
中科院分区：
文献类型：
--
作者：
Wilkinson,BL;Jeromin,A;Roder,J;Hyson,RL
鸟类耳蜗核、大细胞核 (NM) 中的神经元对传入输入的操作高度敏感，通过耳蜗消融去除传入活动会导致约 20-40% 的同侧 NM 神经元死亡。决定单个 NM 神经元死亡或存活的细胞内级联尚不完全清楚。在 NM 中观察到的传入神经阻滞后的一个早期事件是细胞内钙浓度迅速升高。在大多数细胞系统中，钙结合蛋白的活性被认为可以调节钙的流入。钙结合蛋白神经元钙传感器-1 (NCS-1) 是一种细胞内神经元钙传感器，属于 EF-hand 超家族。 NCS-1 与钙依赖性信号级联调节有关。为了评估 NCS-1 在 NM 神经元中的作用，检查了 NCS-1 蛋白的定位。双标记免疫荧光实验表明，NCS-1 在突触前神经末梢和突触后 NM 神经元中都有明显表达。 NCS-1 的突触后表达通常与细胞膜密切相关。 NCS-1 与突触后膜的紧密接近使得 NCS-1 能够充当突触后信号事件的调节剂。传入神经阻滞后，NM 神经元更有可能显示弥散的细胞质 NCS-1 标记。在耳蜗消融后 12 小时和 24 小时观察到显示弥漫性细胞质标记的细胞数量增加，但在手术后 4 天未观察到。 NCS-1 亚细胞定位的这种活性依赖性调节表明它可能与对 NM 神经元生存重要的过程相关或受其影响。
Neurons in the avian cochlear nucleus, nucleus magnocellularis (NM), are highly sensitive to manipulations of afferent input, and removal of afferent activity through cochlear ablation results in the death of approximately 20-40% of ipsilateral NM neurons. The intracellular cascades that determine whether an individual NM neuron will die or survive are not fully understood. One early event observed in NM following deafferentation is a rapid rise in intracellular calcium concentration. In most cellular systems, the activity of calcium-binding proteins is believed to accommodate calcium influx. The calcium-binding protein, neuronal calcium sensor-1 (NCS-1), is an intracellular neuronal calcium sensor belonging to the EF-hand superfamily. NCS-1 has been implicated in calcium-dependent regulation of signaling cascades. To evaluate NCS-1 action in NM neurons, the localization of NCS-1 protein was examined. Double-label immunofluorescence experiments revealed that NCS-1 expression is evident in both the presynaptic nerve terminal and postsynaptic NM neuron. The postsynaptic expression of NCS-1 typically appears to be closely associated with the cell membrane. This close proximity of NCS-1 to the postsynaptic membrane could allow NCS-1 to function as a modulator of postsynaptic signaling events. Following deafferentation, NM neurons were more likely to show diffuse cytoplasmic NCS-1 labeling. This increase in the number of cells showing diffuse cytoplasmic labeling was observed 12 and 24 h following cochlea ablation, but was not observed 4 days following surgery. This activity-dependent regulation of NCS-1 subcellular localization suggests it may be associated with, or influenced by, processes important for the survival of NM neurons.