Synaptic scaling is a key homeostatic plasticity mechanism and is thought to be involved in the regulation of cortical activity levels. Here we investigated the spatial scale of homeostatic changes in spine size following sensory deprivation in a subset of inhibitory (layer 2/3 GAD65-positive) and excitatory (layer 5 Thy1-positive) neurons in mouse visual cortex. Using repeated in vivo two-photon imaging, we find that increases in spine size are tumor necrosis factor alpha (TNF-α) dependent and thus are likely associated with synaptic scaling. Rather than occurring at all spines, the observed increases in spine size are spatially localized to a subset of dendritic branches and are correlated with the degree of recent local spine loss within that branch. Using simulations, we show that such a compartmentalized form of synaptic scaling has computational benefits over cell-wide scaling for information processing within the cell.

中文翻译：

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体内剥夺诱导的稳态脊柱缩放定位于最近经历脊柱损失的树突状分支。

突触缩放是一种关键的稳态可塑性机制，被认为与皮层活动水平的调节有关。在这里，我们研究了小鼠视觉皮层中抑制性（第 2/3 层 GAD65 阳性）和兴奋性（第 5 层 Thy1 阳性）神经元中感觉剥夺后脊柱大小的稳态变化的空间尺度。使用重复的体内双光子成像，我们发现脊柱大小的增加依赖于肿瘤坏死因子 α (TNF-α)，因此可能与突触缩放有关。观察到的脊柱大小的增加不是发生在所有脊柱上，而是在空间上局限于树突分支的一个子集，并且与该分支内最近局部脊柱损失的程度相关。使用模拟，