A Map of Functional Synaptic Connectivity in the Mouse Anteroventral Cochlear Nucleus
A Map of Functional Synaptic Connectivity in the Mouse Anteroventral Cochlear Nucleus
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DOI：
10.1523/jneurosci.4669-13.2014
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发表时间：
2014-02-05
影响因子：
5.3
通讯作者：
Manis, Paul B.
中科院分区：
文献类型：
--
作者：
Campagnola, Luke;Manis, Paul B.
耳蜗核是听觉信息的第一个中央处理器，并向所有主要的脑干和中脑听觉核提供输入。虽然在细胞水平上了解了耳蜗核内的局部电路，但这些电路中连接的空间模式和连接强度尚未得到很好的表征。我们应用了一种新颖的定量方法，利用激光扫描光刺激和谷氨酸释放来绘制局部电路投射到小鼠耳蜗前腹侧核（AVCN）的细胞。测量个体诱发突触事件的振幅和动力学，以揭示突触连接的模式和强度。我们发现，两种主要的兴奋性投射细胞，丛状细胞和t -星状细胞，受到AVCN中d -星状细胞的空间广泛抑制，而受到耳蜗背核结核腹侧细胞的空间有限抑制。此外，t -星状细胞整合d -星状抑制的区域跨越两倍于丛状细胞整合的频率范围。丛状细胞和t星状细胞的一个子集在AVCN的背内侧边界受到未知细胞群的抑制。较小的细胞子集接受AVCN中与的局部激励。我们的研究结果表明，抑制回路可以具有特定于目标的空间收敛、突触强度和受体动力学模式，从而导致不同的光谱和时间处理能力。
The cochlear nuclei are the first central processors of auditory information and provide inputs to all the major brainstem and midbrain auditory nuclei. Although the local circuits within the cochlear nuclei are understood at a cellular level, the spatial patterns of connectivity and the connection strengths in these circuits have been less well characterized. We have applied a novel, quantitative approach to mapping local circuits projecting to cells in the mouse anteroventral cochlear nucleus (AVCN) using laser-scanning photostimulation and glutamate uncaging. The amplitude and kinetics of individual evoked synaptic events were measured to reveal the patterns and strengths of synaptic connections. We found that the two major excitatory projection cell classes, the bushy and T-stellate cells, receive a spatially broad inhibition from D-stellate cells in the AVCN, and a spatially confined inhibition from the tuberculoventral cells of the dorsal cochlear nucleus. Furthermore, T-stellate cells integrate D-stellate inhibition from an area that spans twice the frequency range of that integrated by bushy cells. A subset of both bushy and T-stellate cells receives inhibition from an unidentified cell population at the dorsal-medial boundary of the AVCN. A smaller subset of cells receives local excitation from with in the AVCN. Our results show that inhibitory circuits can have target-specific patterns of spatial convergence, synaptic strength, and receptor kinetics, resulting in different spectral and temporal processing capabilities.