The triphasic intrinsic signal: Implications for functional imaging
The triphasic intrinsic signal: Implications for functional imaging
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DOI：
10.1523/jneurosci.0326-07.2007
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发表时间：
2007-04-25
影响因子：
5.3
通讯作者：
Frostig, Ron D.
中科院分区：
文献类型：
--
作者：
Chen-Bee, Cynthia H.;Agoncillo, Teodora;Frostig, Ron D.
红色照明本征信号光学成像 (ISOI) 广泛用于提供刺激诱发的血流动力学相关信号的高空间分辨率图，作为绘制诱发神经元活动图的间接方法。这种诱发信号通常被描述为以信号下冲或“下降”开始，与随后的信号过冲相比，该信号更快、更瞬态且更弱。相比之下，血氧水平依赖性 (BOLD) 功能磁共振成像 (fMRI) 检测到的诱发信号通常被描述为在初始下降和过冲后包含下冲，尽管它也检测到血流动力学相关信号，并且其前两个相位似乎与 ISOI 的信号互补。在这里，我们使用 635 nm 照明的 ISOI 在 1 s 刺激传递后的 13.5 s 内成像，以检测并成功使用 ISOI 下冲阶段进行功能映射。每个信号相位评估了八个时空属性，包括最大面积范围和峰值幅度，这两者对于 ISOI 过冲来说都是最大的，其次是下冲，然后是初始下降。三个阶段之间的峰值活动位置没有很好地共定位；此外，我们发现每个阶段内的属性之间的相关性大多适中，而阶段之间的相关性则稀疏。延长（13.5 秒）的电生理学记录没有表现出可能与下冲相关的诱发阈上或阈下神经元反应的再次发生。除了下冲之外，还绘制了额外的过冲/下冲波动，但通常对刺激传递的时空特异性较小。讨论了 ISOI 和 BOLD fMRI 的影响。
Intrinsic signal optical imaging with red illumination (ISOI) is used extensively to provide high spatial resolution maps of stimulus-evoked hemodynamic-related signals as an indirect means to map evoked neuronal activity. This evoked signal is generally described as beginning with an undershoot or "dip" in signal that is faster, more transient, and weaker compared with the subsequent signal overshoot. In contrast, the evoked signal detected with blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is generally described as containing an undershoot after the initial dip and overshoot, even though it, too, detects hemodynamic-related signals and its first two phases appear complementary to those of ISOI. Here, we used ISOI with 635 nm illumination to image over 13.5 s after a 1 s stimulus delivery to detect and successfully use the ISOI undershoot phase for functional mapping. Eight spatiotemporal attributes were assessed per signal phase including maximum areal extent and peak magnitude, both of which were largest for the ISOI overshoot, followed by the undershoot and then the initial dip. Peak activity location did not colocalize well between the three phases; furthermore, we found mostly modest correlations between attributes within each phase and sparse correlations between phases. Extended (13.5 s) electrophysiology recordings did not exhibit a reoccurrence of evoked suprathreshold or subthreshold neuronal responses that could be associated with the undershoot. Beyond the undershoot, additional overshoot/undershoot fluctuations were also mapped, but were typically less spatiotemporally specific to stimulus delivery. Implications for ISOI and BOLD fMRI are discussed.