单个和多个囊泡的融合会在中央突触中诱导不同速率的内细胞分裂
Jian-Yuan Sun1, Xin-Sheng Wu, Ling-Gang Wu
1Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Nature
|May 31, 2002
概括
随着活动的增加,突触传输后囊泡的检索速度会减慢. 在血中积聚未恢复的囊泡可能会调节细胞内和短期的突触抑制.
科学领域:
- 神经科学是一个神经科学.
- 细胞生物学 细胞生物学
- 突触性可塑性 突触性可塑性
背景情况:
- 突触传输依赖于神经递质囊泡的融合和检索,以持续发送信号.
- 内细胞突变动力学对于维持囊泡供应至关重要,但在生理条件下对其了解甚微.
- 以前的研究经常使用非生理刺激,限制了对自然突触功能的洞察力.
研究的目的:
- 为了研究在哺乳动物中枢突触处的生理刺激后内细胞突变的动力学.
- 确定刺激频率和外细胞形成率如何影响内细胞形成.
- 提出一种新的内细胞调节机制.
主要方法:
- 利用电容测量来追踪单个和多个囊泡的融合和检索.
- 在哺乳动物中枢突触中应用了轻度的生理刺激协议.
- 在不同的刺激频率下分析了内细胞化时间常数.
主要成果:
- 单囊泡融合后的内细胞形成时间常数为56毫秒.
- 在低刺激频率 (<或=2 Hz) 时,内细胞形成需要大约115 ms.
- 内细胞分裂显著减缓,达到几十秒钟,刺激频率和动作潜能数量增加.
- 外细胞突变率与内细胞突变率正相关,挑战现有模型.
结论:
- 随着外细胞分裂率的增加,内细胞分裂率下降,这表明存在反机制.
- 在等离子膜上积聚未恢复的囊泡可能会抑制内细胞形成.
- 这些发现解决了关于刺激频率依赖的争论,并表明内细胞调节在短期突触抑郁中的作用.
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