Dynamics of rat entorhinal cortex layer II and III cells: characteristics of membrane potential resonance at rest predict oscillation properties near threshold
Dynamics of rat entorhinal cortex layer II and III cells: characteristics of membrane potential resonance at rest predict oscillation properties near threshold
复制标题
DOI：
10.1113/jphysiol.2004.069930
复制
发表时间：
2004-10-01
影响因子：
5.5
通讯作者：
Herz, AVM
中科院分区：
文献类型：
--
作者：
Erchova, I;Kreck, G;Herz, AVM
神经元在不同的生理和行为条件下产生固有的阈下膜电位振荡（MPO）。这些振荡在许多层面上影响神经反应和编码特性。在单细胞水平上，MPO调节动作电位的时间精度;它们对大规模皮层活动也有明显的影响。最近的研究已经描述了给定神经元的MPO与其电共振特性之间的密切关联。使用细胞内尖锐的微电极记录，我们研究了内嗅皮层（EC）的第二和第三层的动力学特性。我们从EC层II星状细胞的数据显示出强烈的膜电位共振和振荡，都在5-15 Hz的范围内。在谐振最大值处，膜阻抗可以大于输入电阻的两倍。在EC层III细胞中，不能引起MPO，并且频率分辨阻抗随着频率的增加单调衰减，或者只有一个小的峰值，随后是随后的衰减。为了量化和比较共振和振荡特性，我们使用一个简单的数学模型，其中包括随机分量来捕获信道噪声。基于这个模型，我们证明了电共振是密切相关的，但不等同于发生的凹陷电位和MPO。MPO频率可以从星状细胞的膜阻抗曲线预测。该模型还解释了所观察到的MPO的宽带性质。这强调了阈下现象的内在噪声源的重要性，并排除了MPO的确定性描述。此外，我们的研究结果表明，在表面EC层，这是已知的目标在海马体中的不同区域的两个确定的细胞类，也有不同的首选频率范围和动态特性。因此，内在的细胞特性可能在海马结构中的频率依赖性信息流中发挥重要作用。
Neurones generate intrinsic subthreshold membrane potential oscillations (MPOs) undervarious physiological and behavioural conditions. These oscillations influence neural responses and coding properties on many levels. On the single-cell level, MPOs modulate the temporal precision of action potentials; they also have a pronounced impact on large-scale cortical activity. Recent studies have described a close association between the MPOs of a given neurone and its electrical resonance properties. Using intracellular sharp microelectrode recordings we examine both dynamical characteristics in layers II and III of the entorhinal cortex (EC). Our data from EC layer II stellate cells show strong membrane potential resonances and oscillations, both in the range of 5-15 Hz. At the resonance maximum, the membrane impedance can be more than twice as large as the input resistance. In EC layer III cells, MPOs could not be elicited, and frequency-resolved impedances decay monotonically with increasing frequency or has only a small peak followed by a subsequent decay. To quantify and compare the resonance and oscillation properties, we use a simple mathematical model that includes stochastic components to capture channel noise. Based on this model we demonstrate that electrical resonance is closely related though not equivalent to the occurrence of sag-potentials and MPOs. MPO frequencies can be predicted from the membrane impedance curve for stellate cells. The model also explains the broad-band nature of the observed MPOs. This underscores the importance of intrinsic noise sources for subthreshold phenomena and rules out a deterministic description of MPOs. In addition, our results show that the two identified cell classes in the superficial EC layers, which are known to target different areas in the hippocampus, also have different preferred frequency ranges and dynamic characteristics. Intrinsic cell properties may thus play a major role for the frequency-dependent information flow in the hippocampal formation.