Time-course and mechanisms of homeostatic plasticity in layers 2/3 and 5 of the barrel cortex.
Time-course and mechanisms of homeostatic plasticity in layers 2/3 and 5 of the barrel cortex.
复制标题
桶皮层2/3和5层中稳态可塑性的时间阶段和机制。
DOI：
10.1098/rstb.2016.0150
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发表时间：
2017-03-05
期刊：
影响因子：
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通讯作者：
Fox K
中科院分区：
文献类型：
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作者：
Glazewski S;Greenhill S;Fox K
最近的研究表明，视皮层2/3层的眼优势可塑性表现出一种与突触缩放相关的稳态可塑性，并依赖于TNFα。在这项研究中，我们测试了是否有类似形式的可塑性存在于2/3层的桶皮质，因此，该机制是否可能是一个一般性质的皮质神经元。我们发现，胡须剥夺可以诱导稳态可塑性的2/3层的桶皮质，但不是在小鼠品系缺乏突触缩放。2/3层稳态可塑性的时程与L5规则发放（RS）神经元（L5 RS）相似，但慢于L5内在爆发（IB）神经元（L5 IB）。在第5层，诱发的晶须反应的强度和离体微型兴奋性突触后电流（mEPSC）的幅度表现出相同的时间过程的稳态可塑性，这意味着可塑性兴奋性突触接触层5神经元足以解释诱发反应的变化。自发放电率也表现出稳态行为的L5 IB细胞，但不存在的L5 RS细胞在研究的时间过程。自发放电率稳态被认为是独立的诱发反应稳态表明这两个依赖于不同的机制。这篇文章是“整合赫布和稳态可塑性”主题问题的一部分。
Recent studies have shown that ocular dominance plasticity in layer 2/3 of the visual cortex exhibits a form of homeostatic plasticity that is related to synaptic scaling and depends on TNFα. In this study, we tested whether a similar form of plasticity was present in layer 2/3 of the barrel cortex and, therefore, whether the mechanism was likely to be a general property of cortical neurons. We found that whisker deprivation could induce homeostatic plasticity in layer 2/3 of barrel cortex, but not in a mouse strain lacking synaptic scaling. The time-course of homeostatic plasticity in layer 2/3 was similar to that of L5 regular spiking (RS) neurons (L5RS), but slower than that of L5 intrinsic bursting (IB) neurons (L5IB). In layer 5, the strength of evoked whisker responses and ex vivo miniature excitatory post-synaptic currents (mEPSCs) amplitudes showed an identical time-course for homeostatic plasticity, implying that plasticity at excitatory synapses contacting layer 5 neurons is sufficient to explain the changes in evoked responses. Spontaneous firing rate also showed homeostatic behaviour for L5IB cells, but was absent for L5RS cells over the time-course studied. Spontaneous firing rate homeostasis was found to be independent of evoked response homeostasis suggesting that the two depend on different mechanisms. This article is part of the themed issue ‘Integrating Hebbian and homeostatic plasticity’.