Glutamate spillover mediates excitatory transmission in the rat olfactory bulb
Glutamate spillover mediates excitatory transmission in the rat olfactory bulb
复制标题
DOI：
10.1016/s0896-6273(00)80787-4
复制
发表时间：
1999-06-01
期刊：
影响因子：
16.2
通讯作者：
Isaacson, JS
中科院分区：
文献类型：
--
作者：
Isaacson, JS
在中枢神经系统中，谷氨酸通常通过突触接触的局部作用介导兴奋性传递。在嗅球中，二尖瓣细胞树突释放谷氨酸仅在抑制性颗粒细胞树突上形成的突触上。这里，我展示了嗅球切片中二尖瓣细胞之间仅通过递质溢出介导的兴奋性传递。树突状谷氨酸释放个体二尖瓣细胞通过局部激活n -甲基- d -天冬氨酸（NMDA）受体引起自激。配对记录显示，一个细胞释放谷氨酸在邻近的二尖瓣细胞中产生NMDA受体介导的反应，这种反应通过阻断谷氨酸摄取而增强。此外，溢出产生自发的NMDA受体介导的群体反应。通过谷氨酸的扩散作用，相邻二尖瓣细胞同时激活，为嗅觉主细胞同步提供了一种机制。
In the CNS, glutamate typically mediates excitatory transmission via local actions at synaptic contacts. In the olfactory bulb, mitral cell dendrites release glutamate at synapses formed only onto the dendrites of inhibitory granule cells, Here, I show excitatory transmission mediated solely by transmitter spillover between mitral cells in olfactory bulb slices. Dendritic glutamate release from individual mitral cells causes self-excitation via local activation of N-methyl-D-aspartate (NMDA) receptors. Paired recordings reveal that glutamate release from one cell generates NMDA receptor-mediated responses in neighboring mitral cells that are enhanced by blockade of glutamate uptake. Furthermore, spillover generates spontaneous NMDA receptor-mediated population responses. This simultaneous activation of neighboring mitral cells by a diffuse action of glutamate provides a mechanism for synchronizing olfactory principal cells.