Neural activity in the brain is usually coupled to increases in local cerebral blood flow, leading to the increase in oxygenation that generates the BOLD fMRI signal. Recent work has begun to elucidate the vascular and neural mechanisms underlying the BOLD signal. The dilatory response is distributed throughout the vascular network. Arteries actively dilate within a second following neural activity increases, while venous distensions are passive and have a time course that last tens of seconds. Vasodilation, and thus local blood flow, is controlled by the activity of both neurons and astrocytes via multiple different pathways. The relationship between sensory-driven neural activity and the vascular dynamics in sensory areas are well-captured with a linear convolution model. However, depending on the behavioral state or brain region, the coupling between neural activity and hemodynamic signals can be weak or even inverted.

中文翻译：

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BOLD信号的血管和神经基础。

大脑中的神经活动通常与局部脑血流量增加相关，导致产生BOLD fMRI信号的氧合增加。最近的工作已经开始阐明BOLD信号背后的血管和神经机制。扩张反应分布在整个血管网络中。随着神经活动的增加，动脉在一秒钟内主动扩张，而静脉扩张则是被动的，持续时间长达数十秒。血管舒张以及因此的局部血流受神经元和星形胶质细胞通过多种不同途径的活性控制。使用线性卷积模型可以很好地捕获感觉驱动的神经活动与感觉区域的血管动力学之间的关系。但是，根据行为状态或大脑区域，