Frequency-dependent signal processing in apical dendrites of hippocampal CA1 pyramidal cells
Frequency-dependent signal processing in apical dendrites of hippocampal CA1 pyramidal cells
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海马 CA1 锥体细胞顶端树突的频率依赖性信号处理
DOI：
10.1016/j.neuroscience.2014.07.069
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发表时间：
2014
期刊：
影响因子：
3.3
通讯作者：
Takeshi Aihara
中科院分区：
文献类型：
--
作者：
Hidenori Watanabe;Hiroshi Tsubokawa;Minoru Tsukada;Takeshi Aihara
根据动物的行为状态，海马CA 1区锥体细胞接受不同模式的兴奋性和抑制性突触输入。这些输入的频率的时间依赖性变化和电压门控通道的不均匀分布导致膜电导的动态波动。在这项研究中，使用全细胞膜片钳方法，我们试图记录和分析的频率依赖性的噪声电流直接注入树突和胞体下的所有突触输入的药物阻断的Wistar大鼠海马CA 1区锥体细胞的膜反应性。为了估计膜电位的频率依赖性，从频域中的电压响应除以输入电流来确定膜阻抗。大多数神经元的细胞膜在所有区域都表现出低通滤波特性。特别是，这些特性在胞体或近端树突中强烈表达。此外，数据显示树突阻抗的不均匀分布，其在顶端树突干的中间段（距离索马220-260 μm）中较高。细胞膜去极化对顶树突的低通滤波作用比胞体强。相干谱分析显示，在theta-γ频率范围内的输入信号和输出电压响应之间的高相干性，并且在γ频率范围内的远端树突中出现大的滞后。我们的研究结果表明，海马CA 1区锥体细胞的顶树突整合突触输入根据输入信号的频率成分沿着接受输入的树突节段。
Depending on an animal’s behavioral state, hippocampal CA1 pyramidal cells receive distinct patterns of excitatory and inhibitory synaptic inputs. The time-dependent changes in the frequencies of these inputs and the nonuniform distribution of voltage-gated channels lead to dynamic fluctuations in membrane conductance. In this study, using a whole-cell patch-clamp method, we attempted to record and analyze the frequency dependencies of membrane responsiveness in Wistar rat hippocampal CA1 pyramidal cells following noise current injection directly into dendrites and somata under pharmacological blockade of all synaptic inputs. To estimate the frequency-dependent properties of membrane potential, membrane impedance was determined from the voltage response divided by the input current in the frequency domain. The cell membrane of most neurons showed low-pass filtering properties in all regions. In particular, the properties were strongly expressed in the somata or proximal dendrites. Moreover, the data revealed nonuniform distribution of dendritic impedance, which was high in the intermediate segment of the apical dendritic shaft (∼220–260 μm from the soma). The low-pass filtering properties in the apical dendrites were more enhanced by membrane depolarization than those in the somata. Coherence spectral analysis revealed high coherence between the input signal and the output voltage response in the theta–gamma frequency range, and large lags emerged in the distal dendrites in the gamma frequency range. Our results suggest that apical dendrites of hippocampal CA1 pyramidal cells integrate synaptic inputs according to the frequency components of the input signal along the dendritic segments receiving the inputs.