Bidirectional GABAergic control of action potential firing in newborn hippocampal granule cells
Bidirectional GABAergic control of action potential firing in newborn hippocampal granule cells
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DOI：
10.1038/nn.4218
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发表时间：
2016-02-01
影响因子：
25
通讯作者：
Bischofberger, Josef
中科院分区：
文献类型：
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作者：
Heigele, Stefanie;Sultan, Sebastien;Bischofberger, Josef
成年海马中新产生的年轻神经元接受GABA能突触输入，这对于有丝分裂后1-3周之间的活性依赖性存活和功能成熟至关重要。我们在成年小鼠的这些新生的年轻细胞中发现了突触驱动的动作电位（AP）。尽管GABA能突触输入仍处于阈下，但GABA能突触输入的激活使年轻神经元去极化并可靠地诱发AP。此外，配对的阈下兴奋性突触后电位或体细胞电流注射与短暂的爆发性GABA能输入显示有效的GABA能兴奋在电导类似于1.5 nS，对应于只有三个或四个interneurons的活动。更强的GABA能输入（>4 nS）通过分流抑制有效地阻断AP放电，这对于在两个方向上动态控制尖峰输出可能是重要的。总之，GABA能中间神经元通过支持AP产生或依赖于海马网络活动的分流抑制来差异性地招募新生的年轻颗粒细胞。
Newly generated young neurons in the adult hippocampus receive GABAergic synaptic inputs, which are crucial for activity-dependent survival and functional maturation between 1-3 weeks after mitosis. We found synaptically driven action potential (AP) firing in these newborn young cells in adult mice. Although glutamatergic synaptic inputs remained subthreshold, activation of GABAergic synaptic inputs depolarized young neurons and reliably evoked APs. Furthermore, pairing of subthreshold excitatory postsynaptic potentials or somatic current injection with brief bursts of GABAergic inputs revealed efficient GABAergic excitation at conductances of similar to 1.5 nS, corresponding to the activity of only three or four interneurons. Stronger GABAergic inputs (>4 nS) effectively blocked AP firing via shunting inhibition, which might be important to dynamically control spiking output in both directions. Taken together, GABAergic interneurons differentially recruit newborn young granule cells by supporting either AP generation or shunting inhibition dependent on hippocampal network activity.