Imaging extrasynaptic glutamate dynamics in the brain
Imaging extrasynaptic glutamate dynamics in the brain
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DOI：
10.1073/pnas.0913154107
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发表时间：
2010-04-06
影响因子：
11.1
通讯作者：
Iino, Masamitsu
中科院分区：
文献类型：
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作者：
Okubo, Yohei;Sekiya, Hiroshi;Iino, Masamitsu
谷氨酸是大脑中的主要神经递质，介导兴奋性突触中突触间隙的点对点传递。使用荧光指示剂的谷氨酸成像方法，我们表明，突触活动产生突触外谷氨酸动力学在活跃的突触附近。这些谷氨酸动力学的幅度和持续时间足以激活脑片中的突触外谷氨酸受体。我们还观察到突触之间的串扰，即，相邻突触释放的谷氨酸的总和。此外，我们成功地观察到，从四肢感觉输入诱导突触外谷氨酸动力学在适当的感觉区域内的大脑皮层在体内。因此，本研究阐明了突触外谷氨酸动力学的时空特征，并开辟了一条直接可视化活体动物突触活动的途径。
Glutamate is the major neurotransmitter in the brain, mediating point-to-point transmission across the synaptic cleft in excitatory synapses. Using a glutamate imaging method with fluorescent indicators, we show that synaptic activity generates extrasynaptic glutamate dynamics in the vicinity of active synapses. These glutamate dynamics had magnitudes and durations sufficient to activate extrasynaptic glutamate receptors in brain slices. We also observed crosstalk between synapses-i.e., summation of glutamate released from neighboring synapses. Furthermore, we successfully observed that sensory input from the extremities induced extrasynaptic glutamate dynamics within the appropriate sensory area of the cerebral cortex in vivo. Thus, the present study clarifies the spatiotemporal features of extrasynaptic glutamate dynamics, and opens up an avenue to directly visualizing synaptic activity in live animals.