Voltage-sensitive dye imaging reveals shifting spatiotemporal spread of whisker-induced activity in rat barrel cortex.
Voltage-sensitive dye imaging reveals shifting spatiotemporal spread of whisker-induced activity in rat barrel cortex.
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DOI：
10.1152/jn.00430.2012
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发表时间：
2013-05
影响因子：
2.5
通讯作者：
Brian R. Lustig;R. Friedman;J. Winberry;F. Ebner;A. Roe
中科院分区：
文献类型：
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作者：
Brian R. Lustig;R. Friedman;J. Winberry;F. Ebner;A. Roe
在大鼠中，在环境中导航需要关于头部附近物体的连续信息。感觉信息，如物体的位置和表面纹理编码的单个神经元的放电模式在大鼠桶皮层。虽然有许多研究使用单单位的电生理学，少得多是已知的关于桶皮质中的神经元群体的活动的时空模式，以响应晶须刺激。为了研究群体水平上的皮层反应，我们使用电压敏感染料（VSD）成像来研究整体时空动态的桶皮层在刺激单一或两个相邻的胡须在麻醉大鼠。单根触须刺激在12-16 ms内产生一个刺激后荧光响应峰，对应于受刺激的触须（主触须）。随后，这种荧光在整个桶场传播，沿桶行沿着各向异性地优先传播。在成对的触须刺激后，VSD信号显示出亚线性总和（小于2个单一触须刺激的总和），与先前的电生理和成像研究一致。令人惊讶的是，我们观察到的激活中心的空间移位发生在10至20毫秒的时间内，移位幅度为1-2桶。这种变化主要发生在桶领域内的后内侧方向。因此，我们的数据揭示了以前未报道的桶皮层激活的时空模式。我们认为，这种非地形的转变是一致的桶皮质已知的功能和解剖不对称性，它可能提供了一个重要的见解，了解桶场激活搅拌行为。
In rats, navigating through an environment requires continuous information about objects near the head. Sensory information such as object location and surface texture are encoded by spike firing patterns of single neurons within rat barrel cortex. Although there are many studies using single-unit electrophysiology, much less is known regarding the spatiotemporal pattern of activity of populations of neurons in barrel cortex in response to whisker stimulation. To examine cortical response at the population level, we used voltage-sensitive dye (VSD) imaging to examine ensemble spatiotemporal dynamics of barrel cortex in response to stimulation of single or two adjacent whiskers in urethane-anesthetized rats. Single whisker stimulation produced a poststimulus fluorescence response peak within 12-16 ms in the barrel corresponding to the stimulated whisker (principal whisker). This fluorescence subsequently propagated throughout the barrel field, spreading anisotropically preferentially along a barrel row. After paired whisker stimulation, the VSD signal showed sublinear summation (less than the sum of 2 single whisker stimulations), consistent with previous electrophysiological and imaging studies. Surprisingly, we observed a spatial shift in the center of activation occurring over a 10- to 20-ms period with shift magnitudes of 1-2 barrels. This shift occurred predominantly in the posteromedial direction within the barrel field. Our data thus reveal previously unreported spatiotemporal patterns of barrel cortex activation. We suggest that this nontopographical shift is consistent with known functional and anatomic asymmetries in barrel cortex and that it may provide an important insight for understanding barrel field activation during whisking behavior.