Propagating wave and irregular dynamics: spatiotemporal patterns of cholinergic theta oscillations in neocortex in vitro
Propagating wave and irregular dynamics: spatiotemporal patterns of cholinergic theta oscillations in neocortex in vitro
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DOI：
10.1152/jn.00715.2002
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发表时间：
2003-07-01
影响因子：
2.5
通讯作者：
Wu, JY
中科院分区：
文献类型：
--
作者：
Bao, WL;Wu, JY
在动物和人类受试者中已经观察到新皮层“theta”振荡（5-12 Hz），但是关于振荡在皮层内在网络中是如何组织的知之甚少。在这里，我们使用电压敏感染料和光学成像来研究卡巴胆碱/荷包牡丹碱诱导的大鼠新皮层脑片θ波（类似于8 Hz）振荡。成像具有大的信噪比，使我们能够映射振荡期间新皮层组织上的相位分布。振荡被组织为自发的时期，每个时期由振荡的“第一个尖峰”、“规则”周期（具有相对稳定的频率和振幅）和“不规则”周期（具有可变的频率和振幅）组成。在规则振荡的每个周期中，一个激活波以类似于50 mm/s的速度水平地（平行于皮质层）传播穿过皮质切片。垂直的活动是同步通过所有皮层层。在所有的规则周期中，都可以看到一个传播波与一个振荡周期相关联的这种模式。振荡频率在两个相邻的水平位置（相隔330 μ m）显著变化，这表明振荡是局部组织的，并且每个局部振荡器在水平方向上大约小于或等于300 μ m宽。在不规则振荡期间，时空模式复杂，有时垂直同步分解，表明本地振子之间的解耦。我们的数据表明，新皮层θ振荡是由多个本地振荡器。振荡器之间的耦合机制可以确定时空模式以及传播波和不规则模式之间的切换。
Neocortical "theta" oscillation (5-12 Hz) has been observed in animals and human subjects but little is known about how the oscillation is organized in the cortical intrinsic networks. Here we use voltage-sensitive dye and optical imaging to study a carbachol/bicuculline induced theta (similar to8 Hz) oscillation in rat neocortical slices. The imaging has large signal-to-noise ratio, allowing us to map the phase distribution over the neocortical tissue during the oscillation. The oscillation was organized as spontaneous epochs and each epoch was composed of a "first spike," a "regular" period (with relatively stable frequency and amplitude), and an "irregular" period (with variable frequency and amplitude) of oscillations. During each cycle of the regular oscillation, one wave of activation propagated horizontally (parallel to the cortical lamina) across the cortical section at a velocity of similar to50 mm/s. Vertically the activity was synchronized through all cortical layers. This pattern of one propagating wave associated with one oscillation cycle was seen during all the regular cycles. The oscillation frequency varied noticeably at two neighboring horizontal locations (330 mum apart), suggesting that the oscillation is locally organized and each local oscillator is about less than or equal to300 mum wide horizontally. During irregular oscillations, the spatiotemporal patterns were complex and sometimes the vertical synchronization decomposed, suggesting a de-coupling among local oscillators. Our data suggested that neocortical theta oscillation is sustained by multiple local oscillators. The coupling regime among the oscillators may determine the spatiotemporal pattern and switching between propagating waves and irregular patterns.