Synaptogenesis of electrical and GABAergic synapses of fast-spiking inhibitory neurons in the neocortex.
Synaptogenesis of electrical and GABAergic synapses of fast-spiking inhibitory neurons in the neocortex.
复制标题
DOI：
10.1523/jneurosci.6655-10.2011
复制
发表时间：
2011-07-27
期刊：
影响因子：
--
通讯作者：
Hestrin S
中科院分区：
文献类型：
--
作者：
Pangratz-Fuehrer S;Hestrin S
表达小白蛋白的快峰(FS)细胞通过GABA能突触和电突触相互连接，是新皮质中一类主要的抑制性中间神经元。FS细胞之间的突触连接对于调节成熟新皮质的网络振荡至关重要。然而，目前尚不清楚FS中间神经元之间的突触连接是否也在未成熟大脑中模式神经元活动的产生中发挥核心作用，这被认为是新皮质回路形成的基础。在此，我们研究了小鼠视皮层内FS细胞突触发生的发育时程。在第5/6层(L5/6)，我们记录了两个或三个FS和/或锥体神经元(P)，以研究从出生后第3天(P3)到P18的突触电和化学相互作用的发展。但是，到P5-6，我们发现20%的FS对是电耦合的，24%的FS对是通过GABA能突触连接的；到P15-18时，42%的FS对已经建立了功能性电突触，47%的FS对通过GABA能突触连接。FS细胞GABA能抑制锥体细胞呈现相似的发育时间线，但未检测到FS-P对的电耦合。我们发现，在同一时期，FS细胞的电和GABA能联系的突触发生。综上所述，我们的结果表明，FS细胞之间的化学和电连接只有在出生后第一周结束时才能促进新皮质活动的模式化。
Parvalbumin-expressing fast-spiking (FS) cells are interconnected via GABAergic and electrical synapses and represent a major class of inhibitory interneurons in the neocortex. Synaptic connections among FS cells are critical for regulating network oscillations in the mature neocortex. However, it is unclear whether synaptic connections among FS interneurons also play a central role in the generation of patterned neuronal activity in the immature brain, which is thought to underlie the formation of neocortical circuits. Here, we investigated the developmental time course of synaptogenesis of FS cell in mouse visual cortex. In layer 5/6 (L5/6), we recorded from two or three FS and/or pyramidal neurons (P) to study the development of electrical and chemical synaptic interactions from postnatal day 3 (P3) to P18. We detected no evidence for functional connectivity for FS-FS or FS-P pairs at P3–4. However, by P5–6, we found 20% of FS pairs were electrically coupled and 24% of pairs were connected via GABAergic synapses and by P15–18, 42% of FS pairs had established functional electrical synapses and 47% of FS pairs were connected via GABAergic synapses. FS cell GABAergic inhibition of pyramidal cells showed a similar developmental time line, but no electrical coupling was detected for FS-P pairs. We found that synaptogenesis of electrical and GABAergic connection of FS cells takes place in the same period. Together, our results suggest that chemical and electrical connections among FS cells can contribute to patterned neocortical activity only by the end of the first postnatal week.