Laminar-Specific Maturation of GABAergic Transmission and Susceptibility to Visual Deprivation Are Related to Endocannabinoid Sensitivity in Mouse Visual Cortex
Laminar-Specific Maturation of GABAergic Transmission and Susceptibility to Visual Deprivation Are Related to Endocannabinoid Sensitivity in Mouse Visual Cortex
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DOI：
10.1523/jneurosci.2979-10.2010
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发表时间：
2010-10-20
影响因子：
5.3
通讯作者：
Tsumoto, Tadaharu
中科院分区：
文献类型：
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作者：
Jiang, Bin;Sohya, Kazuhiro;Tsumoto, Tadaharu
据报道，视觉体验改变神经元反应的发育期在视皮层第4层比在第2/3层开始和结束得早，GABA能抑制回路的成熟被认为决定了这一时期的时间。在这里，我们研究是否在这样的时间的层状差异对应于GABA能突触传递到星星锥体和锥体细胞的功能成熟的时间过程中的差异，分别在第4层和2/3层，小鼠视觉皮层和是否GABA能传递的强度的发展受到视觉剥夺在一个特定的方式。我们分析了电刺激传入神经或快速发放GABA能神经元的动作电位诱发的星星锥体细胞和锥体细胞抑制性突触后电流的发育变化，发现GABA能功能从第4层到第2/3层有一个顺序成熟。第4层的抑制成熟发生在出生后3周，比第2/3层早1周。暗饲养的视觉剥夺阻止了第2/3层GABA能传递功能的发育，而暗饲养对第4层GABA能传递功能的发育没有影响。第2/3层的GABA能突触对大麻素1型受体激动剂敏感，在受体敲除小鼠中通常不成熟，而第4层的GABA能突触则不成熟。这些结果表明，特定的层状成熟的抑制和视觉剥夺的敏感性，这可能与层状差异的内源性大麻素的敏感性。
The developmental periodwhenneuronal responses are modified by visual experience is reported to start and end earlier in layer 4 than in layer 2/3 of the visual cortex, and the maturation of GABAergic inhibitory circuits issuggestedtodeterminethetimingof this period. Here, we examine whether the laminar difference in such timing corresponds to a difference in the time course of the functional maturation of GABAergic synaptic transmission to star pyramidal and pyramidal cells in layers 4 and 2/3, respectively, of the mouse visual cortex and whether the development of the strength of GABAergic transmission is affected by visual deprivation in a laminar-specific manner. Our analysis of developmental changes in inhibitory postsynaptic currents of star pyramidal and pyramidal cells evoked by electrical stimulation of afferents or action potentials of fast-spiking GABAergic neurons revealed that there was a sequential maturation of GABAergic function from layers 4 to 2/3. The maturation of inhibition in layer 4 occurred at postnatal week 3, which preceded by 1 week that of layer 2/3. Visual deprivation by dark rearing arrested the functional development of GABAergic transmission in layer 2/3, whereas dark rearing was not so effective in layer 4. GABAergic synapses in layer 2/3 were sensitive to an agonist for cannabinoid type 1 receptors and not normally matured in receptor knock-out mice, whereas those in layer 4were not so. These results suggest laminar-specific maturation of inhibition and susceptibility to visual deprivation, which may be related to the laminar difference in sensitivity to endocannabinoids.