在体内对干扰的敏感性意味着高噪音,并表明皮质中的速率编码
Michael London1, Arnd Roth, Lisa Beeren
1Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
Nature
|July 3, 2010
概括
神经活动会放大小小的干扰,从而产生内在的噪音. 这表明大脑主要使用速率代码进行可靠的神经计算,而不是依赖复杂的信号事件.
科学领域:
- 神经科学是一个神经科学.
- 计算神经科学是一种神经科学.
背景情况:
- 神经活动的变异性是一个已知的现象,但其解释为噪音或信息仍在争论中.
- 了解神经变化的来源和意义对于破译大脑功能至关重要.
研究的目的:
- 为了调查皮层网络中的小扰动是否被放大.
- 确定这种放大对神经编码和信息处理的影响.
主要方法:
- 在体内,在老鼠的皮层中记录了全细胞补丁的记录.
- 同时进行细胞内和细胞外记录.
- 神经网络动态的理论分析.
主要成果:
- 一个神经元中的单个额外的尖峰导致了大约28个附加尖峰的 postsynaptic目标.
- 一个单个神经元尖峰导致局部网络的发射速度明显增加.
- 放大导致内在的,刺激独立的膜电位变化为+/-2.2-4.5mV,被解释为噪声.
结论:
- 皮层网络显示神经活动干扰的显著放大.
- 这种放大会产生内在噪声,这表明像同火链这样的复杂信号事件是罕见的.
- 研究结果支持这样一个假设:大脑皮层主要使用一个速率代码来进行可靠的神经计算.
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