Input-specific GABAergic signaling to newborn neurons in adult dentate gyrus.
Input-specific GABAergic signaling to newborn neurons in adult dentate gyrus.
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DOI：
10.1523/jneurosci.2727-09.2009
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发表时间：
2009-12-02
期刊：
影响因子：
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通讯作者：
Overstreet-Wadiche LS
中科院分区：
文献类型：
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作者：
Markwardt SJ;Wadiche JI;Overstreet-Wadiche LS
成体神经发生是由成体神经干细胞生成神经元的多阶段过程。越来越多的证据表明gaba能去极化是这一过程的重要调节因子。在这里，我们研究了成年小鼠齿状回新生成颗粒细胞（GCs）的gaba能信号。我们发现新生儿GCs的第一个突触电流是由GABA激活GABAA受体产生的，其时空分布表明递质溢出。然而，gaba能反应不是由于周围突触的溢出。相反，我们的研究结果表明，新生GCs中缓慢的突触反应是由在突触后受体上产生相对低浓度GABA的专用输入产生的，类似于成熟GCs中缓慢的IPSCs。当神经元间网络同步活跃时，这种形式的突触信号驱动新生GCs强劲的相位去极化，揭示了通过突触释放GABA将海马活动转化为调节成人神经发生的潜在机制。
Adult neurogenesis is the multistage process of generating neurons from adult neural stem cells. Accumulating evidence indicates that GABAergic depolarization is an important regulator of this process. Here we examined GABAergic signaling to newly generated granule cells (GCs) of the adult mouse dentate gyrus. We show that the first synaptic currents in newborn GCs are generated by activation of GABAA receptors by GABA with a spatiotemporal profile suggestive of transmitter spillover. However, the GABAergic response is not due to spillover from surrounding perisomatic synapses. Rather, our results suggest that slow synaptic responses in newborn GCs are generated by dedicated inputs that produce a relatively low concentration of GABA at postsynaptic receptors, similar to slow IPSCs in mature GCs. This form of synaptic signaling drives robust phasic depolarization of newborn GCs when the interneuron network is synchronously active, revealing a potential mechanism that translates hippocampal activity into regulation of adult neurogenesis via synaptic release of GABA.