Dynamics of learning-induced spine redistribution along dendrites of pyramidal neurons in rats
Dynamics of learning-induced spine redistribution along dendrites of pyramidal neurons in rats
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DOI：
10.1111/j.1460-9568.2005.03936.x
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发表时间：
2005-02-01
影响因子：
3.4
通讯作者：
Barkai, E
中科院分区：
文献类型：
--
作者：
Knafo, S;Libersat, F;Barkai, E
我们以前已经表明，嗅觉辨别（OD）学习伴随着增强的棘密度沿着近端顶树突的第二层锥体神经元梨状（嗅觉）皮层。在这里，我们研究了学习诱导的修改树突棘密度在整个树突树的这些神经元的时间动态。我们观察到OD学习后近端顶棘密度的短暂增加，这表明嗅觉皮层内神经元互连的内在兴奋性输入的加强。相比之下，从嗅球接收直接输入的传入通路显示出脊修剪，这表明连接性减弱。棘密度的变化可以归因于棘数量的净变化，因为树突的形态参数不受学习的影响。我们认为，棘密度的变化可能代表了嗅觉学习巩固所需的选择性突触重组的机制。
We have previously shown that olfactory-discrimination (OD) learning is accompanied by enhanced spine density along proximal apical dendrites of layer II pyramidal neurons in the piriform (olfactory) cortex. Here we studied the temporal dynamics of learning-induced modifications in dendritic spine density throughout the dendritic trees of these neurons. We observed a transient increase in proximal apical spine density after OD learning, suggesting a strengthening of intrinsic excitatory inputs interconnecting neurons within the olfactory cortex. By contrast, the afferent pathway receiving direct input from the olfactory bulb shows spine pruning, suggesting that the connectivity is weakened. The changes in spine density can be attributed to a net change in number of spines, as the morphometric parameters of the dendrites are unaffected by learning. We suggest that spine density changes may represent a mechanism of selective synaptic reorganization required for olfactory learning consolidation.