Membrane potential of CA3 hippocampal pyramidal cells during postnatal development.
Membrane potential of CA3 hippocampal pyramidal cells during postnatal development.
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DOI：
10.1152/jn.00172.2003
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发表时间：
2003-11
影响因子：
2.5
通讯作者：
R. Tyzio;A. Ivanov;C. Bernard;G. Holmes;Y. Ben‐Ari;R. Khazipov
中科院分区：
文献类型：
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作者：
R. Tyzio;A. Ivanov;C. Bernard;G. Holmes;Y. Ben‐Ari;R. Khazipov
去极化静息膜电位一直被认为是未成熟神经元的普遍特征。尽管具有生理重要性，但人们对这种发育现象的潜在机制知之甚少。采用穿孔膜片、全细胞和细胞贴附记录法，对出生后大鼠海马脑片CA 3区锥体细胞膜电位进行了测量。用短杆菌肽穿孔斑记录，出生后P0-P2天的膜电位为-44 +/- 4（SE）mV，在P13-15天逐渐变为-67 +/- 2 mV。用常规的全细胞记录也观察到膜电位的类似的发育变化。然而，从细胞贴附记录中N-甲基-d-天冬氨酸通道的逆转电位推导出的膜电位值不随年龄变化，在P2时为-77 +/- 2 mV，在P13-14时为-77 +/- 2 mV。使用全细胞记录测量的膜电位与密封和输入电阻相关，在具有高的，几个千兆欧姆的输入电阻和低密封电阻的神经元中最去极化。模拟结果表明，去极化值的膜电位在整个细胞和穿孔补丁记录可以解释通过密封之间的移液管和膜接触的分流。因此，CA 3锥体细胞的膜电位在出生时似乎是强负的，并且在出生后的发育过程中不发生变化。
A depolarized resting membrane potential has long been considered to be a universal feature of immature neurons. Despite the physiological importance, the underlying mechanisms of this developmental phenomenon are poorly understood. Using perforated-patch, whole cell, and cell-attached recordings, we measured the membrane potential in CA3 pyramidal cells in hippocampal slices from postnatal rats. With gramicidin perforated-patch recordings, membrane potential was -44 +/- 4 (SE) mV at postnatal days P0-P2, and it progressively shifted to -67 +/- 2 mV at P13-15. A similar developmental change of the membrane potential has been also observed with conventional whole cell recordings. However, the value of the membrane potential deduced from the reversal potential of N-methyl-d-aspartate channels in cell-attached recordings did not change with age and was -77 +/- 2 mV at P2 and -77 +/- 2 mV at P13-14. The membrane potential measured using whole cell recordings correlated with seal and input resistance, being most depolarized in neurons with high, several gigaohms, input resistance and low seal resistance. Simulations revealed that depolarized values of the membrane potential in whole cell and perforated-patch recordings could be explained by a shunt through the seal contact between the pipette and membrane. Thus the membrane potential of CA3 pyramidal cells appears to be strongly negative at birth and does not change during postnatal development.