Simulations of the role of the muscarinic-activated calcium-sensitive nonspecific cation current INCM in entorhinal neuronal activity during delayed matching tasks
Simulations of the role of the muscarinic-activated calcium-sensitive nonspecific cation current INCM in entorhinal neuronal activity during delayed matching tasks
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DOI：
10.1523/jneurosci.22-03-01081.2002
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发表时间：
2002-02-01
影响因子：
5.3
通讯作者：
Hasselmo, ME
中科院分区：
文献类型：
--
作者：
Fransén, E;Alonso, AA;Hasselmo, ME
鼻内病变会损害延迟匹配任务的表现，而毒蕈碱胆碱能受体的阻断也会损害这些任务的表现。生理数据表明，毒蕈碱胆碱能受体刺激激活内嗅神经元的内在细胞电流，这可能是内嗅皮层在执行这些任务中的作用的基础。在这里，我们使用网络生物物理模拟的内嗅皮层，以证明这种细胞机制在行为任务中的潜在作用。模拟演示了如何毒蕈碱激活的钙敏感的非特异性阳离子电流I-NCM可以提供延迟匹配任务的性能过程中观察到的神经元活动的功能的细胞机制。特别是，I-NCM可以支持（1）在延迟期间维持持续的尖峰活动，（2）在匹配期间相对于采样期间增强尖峰活动，以及（3）持续活动对干扰物的抵抗。模拟一个更大的内嗅网络，在数量，分布和重量的限制内随机选择连接，证明了在清醒动物的单位记录中观察到的其他现象的出现，包括匹配抑制，非匹配增强和非匹配抑制。
Entorhinal lesions impair performance in delayed matching tasks, and blockade of muscarinic cholinergic receptors also impairs performance in these tasks. Physiological data demonstrate that muscarinic cholinergic receptor stimulation activates intrinsic cellular currents in entorhinal neurons that could underlie the role of entorhinal cortex in performance of these tasks. Here we use a network biophysical simulation of the entorhinal cortex to demonstrate the potential role of this cellular mechanism in the behavioral tasks. Simulations demonstrate how the muscarinic-activated calcium-sensitive nonspecific cation current I-NCM could provide a cellular mechanism for features of the neuronal activity observed during performance of delayed matching tasks. In particular, I-NCM could underlie (1) the maintenance of sustained spiking activity during the delay period, (2) the enhancement of spiking activity during the matching period relative to the sample period, and (3) the resistance of sustained activity to distractors. Simulation of a larger entorhinal network with connectivity chosen randomly within constraints on number, distribution, and weight demonstrates appearance of other phenomena observed in unit recordings from awake animals, including match suppression, non-match enhancement, and non-match suppression.