Distal gap junctions and active dendrites can tune network dynamics.
Distal gap junctions and active dendrites can tune network dynamics.
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远端间隙连接和活跃树突可以调节网络动态。
DOI：
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发表时间：
2006
影响因子：
2.5
通讯作者：
F. Skinner
中科院分区：
文献类型：
--
作者：
F. Saraga;L. Ng;F. Skinner
缝隙连接允许CNS神经元之间的直接电通信。从理论和建模研究中，众所周知，虽然间隙连接可以起到同步网络输出的作用，但它们也可以引起许多其他动态模式，包括反相和其他锁相状态。产生的特定网络模式取决于影响放电频率的细胞内在特性以及差距连接的强度和位置。海马中的中间神经元或GABA能神经元在它们的细胞特征上是多样的，并且已经被证明具有活跃的树突。此外，小清蛋白阳性GABA能神经元，也称为篮状细胞，可以通过其远端树突上的间隙连接彼此接触。使用双细胞网络模型，我们探讨了远端电连接如何影响网络输出。我们使用NEURON建立了海马篮状细胞的多室模型，并赋予它们不同数量的活性树突。这些模型的细胞，以及减少版本的两个细胞网络进行了探索。固有频率和活性树突水平之间的关系使我们能够根据远端间隙连接耦合发生的网络动力学类型来定义三个区域。弱耦合理论被用来预测这些区域的划定，以及检查的相位响应曲线和远端树枝状极化水平。我们发现，网络的动态特性（相位滞后）对间隙结电导的非单调依赖。这表明远端电耦合和活性树突水平可以控制网络动态对间隙连接调制的敏感程度。对于扩展的几何形状，位于更远位置的间隙连接必须具有更大的电导以发生纯同步。此外，基于与异构网络的模拟，它可能是一个需要活性树突，如果锁相发生在网络形成的远端间隙连接。
Gap junctions allow direct electrical communication between CNS neurons. From theoretical and modeling studies, it is well known that although gap junctions can act to synchronize network output, they can also give rise to many other dynamic patterns including antiphase and other phase-locked states. The particular network pattern that arises depends on cellular, intrinsic properties that affect firing frequencies as well as the strength and location of the gap junctions. Interneurons or GABAergic neurons in hippocampus are diverse in their cellular characteristics and have been shown to have active dendrites. Furthermore, parvalbumin-positive GABAergic neurons, also known as basket cells, can contact one another via gap junctions on their distal dendrites. Using two-cell network models, we explore how distal electrical connections affect network output. We build multi-compartment models of hippocampal basket cells using NEURON and endow them with varying amounts of active dendrites. Two-cell networks of these model cells as well as reduced versions are explored. The relationship between intrinsic frequency and the level of active dendrites allows us to define three regions based on what sort of network dynamics occur with distal gap junction coupling. Weak coupling theory is used to predict the delineation of these regions as well as examination of phase response curves and distal dendritic polarization levels. We find that a nonmonotonic dependence of network dynamic characteristics (phase lags) on gap junction conductance occurs. This suggests that distal electrical coupling and active dendrite levels can control how sensitive network dynamics are to gap junction modulation. With the extended geometry, gap junctions located at more distal locations must have larger conductances for pure synchrony to occur. Furthermore, based on simulations with heterogeneous networks, it may be that one requires active dendrites if phase-locking is to occur in networks formed with distal gap junctions.
影响因子：
2.5
作者：
CARNEVALE, NT;JOHNSTON, D
通讯作者：
JOHNSTON, D
影响因子：
5.5
作者：
Traub, RD;Whittington, MA;Jefferys, JGR
通讯作者：
Jefferys, JGR