The dynamics of spatiotemporal response integration in the somatosensory cortex of the vibrissa system
The dynamics of spatiotemporal response integration in the somatosensory cortex of the vibrissa system
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DOI：
10.1523/jneurosci.4056-05.2006
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发表时间：
2006-04-05
影响因子：
5.3
通讯作者：
Stanley, GB
中科院分区：
文献类型：
--
作者：
Boloori, AR;Stanley, GB
跨神经感受野的时空反应整合是感觉编码的一般特征，在形成对自然刺激的反应中起着重要作用。在大鼠触觉通路的初级躯体感觉皮层中，这种跨越触觉阵列的整合强烈地塑造了时空分布偏转的编码。使用时空双脉冲范式，这项研究揭示了根本不同类型的成对相互作用具有相似的定性行为，但神经反应的大小、潜伏期和精确度取决于参与的特定RF组件。然而，在所有情况下，反应幅度抑制的增加伴随着潜伏期的延长和反应精确度的降低。此外，刺激多个RF亚区引起的非线性相互作用强烈影响对更复杂序列的反应幅度和时序。尽管它们很复杂，但这种反应相互作用从基本的成对相互作用中是高度可预测的。为了理解时空相互作用在编码中的功能作用，我们开发了一个反应模型，其中包括了由交叉触觉相互作用引起的反应幅度、潜伏期和精确度方面的实验测量的调制。对一个简化的纹理识别任务的模拟表明，在一定的刺激时间尺度下，时空交互作用增强了识别能力。这一改进源于一种非线性响应特性，该特性在面临抑制时恢复神经响应。总之，目前的发现强调了反应整合在塑造单细胞反应中的作用，并提供了关于反应参数的变化如何影响编码准确性的预测。
Spatiotemporal response integration across the neural receptive field (RF) is a general feature of sensory coding and has an important role in shaping responses to naturalistic stimuli. In the primary somatosensory cortex of the rat vibrissa pathway, such integration across the vibrissa array strongly shapes the coding of spatiotemporally distributed deflections. Using a spatiotemporal paired-pulse paradigm, this study revealed that fundamentally different types of pairwise interactions have similar qualitative behavior but that the magnitude, latency, and precision of the neural responses depend on the specific RF components being engaged. In all cases, however, increase in the suppression of response magnitude accompanied a lengthening of latency and a decrease in response precision. Furthermore, nonlinear interactions evoked by stimulation of multiple RF subregions strongly influence both response magnitude and timing to more complex sequences. Despite their complexity, such response interactions are highly predictable from elementary pairwise interactions. To understand the functional role of spatiotemporal interactions in coding, we developed a response model that incorporated the experimentally measured modulations in response magnitude, latency, and precision induced by cross-vibrissa interactions. Simulations of a simplified textural discrimination task indicate that spatiotemporal interactions enhance discrimination under certain stimulus time scales. This improvement follows from a nonlinear response property that acts to restore the neural response in the face of suppression. Together, the present findings highlight the role of response integration in shaping single-cell responses and provide predictions about how changes in response parameters influence coding accuracy.