Reliable activation of immature neurons in the adult hippocampus.
Reliable activation of immature neurons in the adult hippocampus.
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DOI：
10.1371/journal.pone.0005320
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Schinder AF
中科院分区：
文献类型：
--
作者：
Mongiat LA;Espósito MS;Lombardi G;Schinder AF
在成年齿状回中出生的神经元发育、成熟和连接的时间间隔很长，可以持续6到8周。有人提出，在此期间，发育中的神经元发挥相关的作用，海马信号处理，由于其独特的电特性。然而，尚未成熟的神经元是否可以在突触和功能成熟之前被招募到网络中仍然是未知的。为了解决这个问题，我们使用逆转录病毒表达的绿色荧光蛋白，以确定成年小鼠海马颗粒细胞的发展和研究传入兴奋，内在兴奋性，并在急性切片膜片钳记录放电行为的平衡。我们发现，对年轻的神经元的amatergic输入显着弱于那些成熟的细胞，但刺激皮质兴奋性轴突elarned在任何发育阶段的神经元类似的尖峰的概率。年轻的神经元由于其高输入电阻而在将离子电流转换成膜去极化方面是高效的，当内向整流钾（Kir）电导增加时，其在成熟神经元中大幅降低。成熟神经元中Kir通道的药理学阻断模拟年轻神经元的高兴奋性特征。相反，Kir过表达诱导年轻神经元中的成熟样放电特性。因此，年轻和成熟神经元兴奋性驱动的差异通过膜兴奋性的变化来补偿，从而产生均衡的放电活动。这些观察结果表明，成年海马不断产生一个高度兴奋的年轻神经元能够处理信息的人口。
Neurons born in the adult dentate gyrus develop, mature, and connect over a long interval that can last from six to eight weeks. It has been proposed that, during this period, developing neurons play a relevant role in hippocampal signal processing owing to their distinctive electrical properties. However, it has remained unknown whether immature neurons can be recruited into a network before synaptic and functional maturity have been achieved. To address this question, we used retroviral expression of green fluorescent protein to identify developing granule cells of the adult mouse hippocampus and investigate the balance of afferent excitation, intrinsic excitability, and firing behavior by patch clamp recordings in acute slices. We found that glutamatergic inputs onto young neurons are significantly weaker than those of mature cells, yet stimulation of cortical excitatory axons elicits a similar spiking probability in neurons at either developmental stage. Young neurons are highly efficient in transducing ionic currents into membrane depolarization due to their high input resistance, which decreases substantially in mature neurons as the inward rectifier potassium (Kir) conductance increases. Pharmacological blockade of Kir channels in mature neurons mimics the high excitability characteristic of young neurons. Conversely, Kir overexpression induces mature-like firing properties in young neurons. Therefore, the differences in excitatory drive of young and mature neurons are compensated by changes in membrane excitability that render an equalized firing activity. These observations demonstrate that the adult hippocampus continuously generates a population of highly excitable young neurons capable of information processing.
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影响因子：
25
作者：
Imayoshi, Itaru;Sakamoto, Masayuki;Kageyama, Ryoichiro
通讯作者：
Kageyama, Ryoichiro
影响因子：
5.3
作者：
Atherton, JF;Bevan, MD
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影响因子：
3.4
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Laplagne, Diego A.;Kamienkowski, Juan E.;Schinder, Alejandro F.
通讯作者：
Schinder, Alejandro F.
影响因子：
5.3
作者：
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通讯作者：
Farrant, M
影响因子：
3.4
作者：
Jessberger, S;Kempermann, G
通讯作者：
Kempermann, G