Frequency of subthreshold oscillations at different membrane potential voltages in neurons at different anatomical positions on the dorsoventral axis in the rat medial entorhinal cortex.
Frequency of subthreshold oscillations at different membrane potential voltages in neurons at different anatomical positions on the dorsoventral axis in the rat medial entorhinal cortex.
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DOI：
10.1523/jneurosci.1654-11.2011
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发表时间：
2011-08-31
期刊：
影响因子：
--
通讯作者：
Hasselmo ME
中科院分区：
文献类型：
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作者：
Yoshida M;Giocomo LM;Boardman I;Hasselmo ME
来自内侧内嗅皮层第二层的神经元显示阈下膜电位振荡（SMPOs），这可能有助于内嗅皮层中θ节律的产生和网格细胞放电模式的产生。然而，目前尚不清楚单个神经元是否具有固定的独特振荡频率，或者它们的频率是否取决于细胞中的平均膜电位。因此，我们研究的频率SMPO在不同的膜电位在第二层星状细胞的大鼠内侧内嗅皮层在体外。使用全细胞贴片记录，我们发现，在膜电位的波动显示了一个宽频带的低功率频率附近的静息电位过渡到更窄的频带振荡频率与去极化。从宽带到窄带频率的转变取决于神经元沿着内嗅皮层中的背腹轴的位置，背侧神经元相对于腹侧神经元转变为较低频率振荡而转变为较高频率振荡。一旦SMPO显示窄带频率，则在进一步去极化时未观察到系统频率变化。使用Hodgkin-Huxley式模型的膜电流，我们表明，在不同的背腹位置的SMPO的频率上的去极化的影响的差异可能会产生的H电流的属性的差异。这些数据中的频率变化的属性对于评估内侧内嗅皮层的背腹轴上沿着具有不同间距的网格细胞放电场的生成模型是重要的。
Neurons from layer II of the medial entorhinal cortex show subthreshold membrane potential oscillations (SMPOs) which could contribute to theta-rhythm generation in the entorhinal cortex and to generation of grid cell firing patterns. However, it is unclear if single neurons have a fixed unique oscillation frequency or if their frequency varies depending on the mean membrane potential in a cell. We therefore examined the frequency of SMPOs at different membrane potentials in layer II stellate-like cells of the rat medial entorhinal cortex in vitro. Using whole cell patch recordings, we found that the fluctuations in membrane potential show a broad band of low power frequencies near resting potential that transition to more narrow band oscillation frequencies with depolarization. The transition from broadband to narrow band frequencies depends on the location of the neuron along the dorso-ventral axis in the entorhinal cortex, with dorsal neurons transitioning to higher frequency oscillations relative to ventral neurons transitioning to lower frequency oscillations. Once SMPOs showed a narrow band frequency, systematic frequency changes were not observed with further depolarization. Using a Hodgkin-Huxley style model of membrane currents we show that differences in the influence of depolarization on the frequency of SMPOs at different dorsal to ventral positions could arise from differences in the properties of the h current. The properties of frequency changes in this data are important for evaluating models of the generation of grid cell firing fields with different spacings along the dorsal to ventral axis of medial entorhinal cortex.