A Cellular Mechanism for Graded Persistent Activity in a Model Neuron and Its Implications in Working Memory
A Cellular Mechanism for Graded Persistent Activity in a Model Neuron and Its Implications in Working Memory
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DOI：
10.1007/s10827-005-5474-6
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发表时间：
2005
影响因子：
1.2
通讯作者：
Jun-nosuke Teramae;T. Fukai
中科院分区：
文献类型：
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作者：
Jun-nosuke Teramae;T. Fukai
工作记忆代表大脑在相对短的时间内保存信息的能力。工作记忆被认为是由持续的神经元放电介导的。一个被广泛接受的假设是，持续的活动是由突触输入的反射产生的。然而，最近报道了能够显示持续放电的单个皮层神经元。在这项建模研究中，我们提出了一种细胞机制，以产生持续的多个放电率在单个神经元。在所提出的机制中，三磷酸肌醇（IP3）和Ca2+浓度的增加是通过IP3的形成和IP3诱导的Ca2+从多个亚细胞结构域的储存中释放来实现的。突触后放电频率依赖的开关这些元件可以证明大鼠内嗅神经元的分级持续放电。这种放电率依赖性开关可以扩展到各种细胞内Ca2+信号级联。
Working memory represents the ability of the brain to hold information for relatively short periods of time. Working memory is believed mediated by persistent neuronal firing. A broadly accepted hypothesis is that persistent activity is generated by reverberating synaptic input. However, single cortical neurons capable of showing persistent firing were recently reported. In this modeling study, we propose a cellular mechanism to generate persistent firing of multiple firing rates in single neurons. In the proposed mechanism, bistable concentrations of inositol 1,4,5-trisphosphate (IP3) and Ca2+is achieved by IP3formation and IP3-induced Ca2+release from stores in multiple subcellular domains. A postsynaptic firing rate-dependent switching of these bistable elements can demonstrate graded persistent firing of the rat entorhinal neurons. Such a firing rate-dependent switching may be extended to a variety of intracellular Ca2+signaling cascades.