Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK; Biozentrum, University of Basel, Basel, Switzerland.
Biozentrum, University of Basel, Basel, Switzerland.
Neuron. 2021 Jun 16;109(12):1996-2008.e6. doi: 10.1016/j.neuron.2021.04.017. Epub 2021 May 11.
Sensory processing involves information flow between neocortical areas, assumed to rely on direct intracortical projections. However, cortical areas may also communicate indirectly via higher-order nuclei in the thalamus, such as the pulvinar or lateral posterior nucleus (LP) in the visual system of rodents. The fine-scale organization and function of these cortico-thalamo-cortical pathways remains unclear. We find that responses of mouse LP neurons projecting to higher visual areas likely derive from feedforward input from primary visual cortex (V1) combined with information from many cortical and subcortical areas, including superior colliculus. Signals from LP projections to different higher visual areas are tuned to specific features of visual stimuli and their locomotor context, distinct from the signals carried by direct intracortical projections from V1. Thus, visual transthalamic pathways are functionally specific to their cortical target, different from feedforward cortical pathways, and combine information from multiple brain regions, linking sensory signals with behavioral context.
感觉处理涉及新皮层区域之间的信息流，据认为这些信息流依赖于皮质内的直接投射。然而，皮质区域也可以通过丘脑中的高级核团间接地进行通信，例如在啮齿动物视觉系统中的丘脑枕核或外侧后核（LP）。这些皮质-丘脑-皮质通路的精细组织和功能仍不清楚。我们发现，投射到更高视觉区域的小鼠 LP 神经元的反应可能来自初级视觉皮层（V1）的前馈输入，结合来自许多皮质和皮质下区域的信息，包括上丘。来自 LP 投射到不同更高视觉区域的信号对视觉刺激及其运动环境的特定特征进行调谐，与来自 V1 的皮质内直接投射携带的信号不同。因此，视觉丘脑间通路在功能上与其皮质靶标特异性相关，与前馈皮质通路不同，并且结合来自多个脑区的信息，将感觉信号与行为环境联系起来。
