Functional mapping of single spines in cortical neurons in vivo
Functional mapping of single spines in cortical neurons in vivo
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DOI：
10.1038/nature10193
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发表时间：
2011-07-28
期刊：
影响因子：
64.8
通讯作者：
Konnerth, Arthur
中科院分区：
文献类型：
--
作者：
Chen, Xiaowei;Leischner, Ulrich;Konnerth, Arthur
树突上传入突触输入的个体功能特性和空间排列在哺乳动物大脑中神经元的信息处理中发挥着关键作用(1-4)。尽管最近的工作已经确定了啮齿动物视觉皮层中视觉诱发的局部树突钙信号 (5)，但树突棘水平上对应于个体传入兴奋性突触的感觉诱发信号仍未得到探索 (6)。在这里，我们使用高分辨率双光子成像的新变体（7）来检测体内小鼠皮质神经元单个树突棘中感觉诱发的钙瞬变。声音刺激引起的钙信号需要激活 NMDA（N-甲基-D-天冬氨酸）受体。活跃的棘广泛分布在基底和顶端树突上，不同频率的纯音刺激显示出窄调谐和宽调谐的棘。值得注意的是，针对不同频率调整的树突棘高度散布在相同的树突上：甚至相邻的树突刺也大多调整为不同的频率。因此，我们的结果表明，同一树突的 NMDA 受体依赖性单棘突触输入具有高度异质性。此外，我们的研究为具有单突触分辨率的功能定义的传入感觉输入的体内映射开辟了道路。
The individual functional properties and spatial arrangement of afferent synaptic inputs on dendrites have a critical role in the processing of information by neurons in the mammalian brain(1-4). Although recent work has identified visually-evoked local dendritic calcium signals in the rodent visual cortex(5), sensory-evoked signalling on the level of dendritic spines, corresponding to individual afferent excitatory synapses, remains unexplored(6). Here we used a new variant of high-resolution two-photon imaging(7) to detect sensory-evoked calcium transients in single dendritic spines of mouse cortical neurons in vivo. Calcium signals evoked by sound stimulation required the activation of NMDA (N-methyl-D-aspartate) receptors. Active spines are widely distributed on basal and apical dendrites and pure-tone stimulation at different frequencies revealed both narrowly and widely tuned spines. Notably, spines tuned for different frequencies were highly interspersed on the same dendrites: even neighbouring spines were mostly tuned to different frequencies. Thus, our results demonstrate that NMDA-receptor-dependent single-spine synaptic inputs to the same dendrite are highly heterogeneous. Furthermore, our study opens the way for in vivo mapping of functionally defined afferent sensory inputs with single-synapse resolution.