Department of Neurobiology, Duke University Medical Center, Durham, North Carolina.
J Neurophysiol. 2020 Jul 1;124(1):245-258. doi: 10.1152/jn.00758.2019. Epub 2020 Jun 17.
Adaptation is a ubiquitous feature of sensory processing whereby recent experience shapes future responses. The mouse primary visual cortex (V1) is particularly sensitive to recent experience, where a brief stimulus can suppress subsequent responses for seconds. This rapid adaptation profoundly impacts perception, suggesting that its effects are propagated along the visual hierarchy. To understand how rapid adaptation influences sensory processing, we measured its effects at key nodes in the visual system: in V1, three higher visual areas (HVAs: lateromedial, anterolateral, and posteromedial), and the superior colliculus (SC) in awake mice of both sexes using single-unit recordings. Consistent with the feed-forward propagation of adaptation along the visual hierarchy, we find that neurons in layer 4 adapt less strongly than those in other layers of V1. Furthermore, neurons in the HVAs adapt more strongly, and recover more slowly, than those in V1. The magnitude and time course of adaptation was comparable in each of the HVAs and in the SC, suggesting that adaptation may not linearly accumulate along the feed-forward visual processing hierarchy. Despite the increase in adaptation in the HVAs compared with V1, the effects were similarly orientation specific across all areas. These data reveal that adaptation profoundly shapes cortical processing, with increasing impact at higher levels in the cortical hierarchy, and also strongly influencing computations in the SC. Thus, we find robust, brain-wide effects of rapid adaptation on sensory processing. Rapid adaptation dynamically alters sensory signals to account for recent experience. To understand how adaptation affects sensory processing and perception, we must determine how it impacts the diverse set of cortical and subcortical areas along the hierarchy of the mouse visual system. We find that rapid adaptation strongly impacts neurons in primary visual cortex, the higher visual areas, and the colliculus, consistent with its profound effects on behavior.
适应是感觉处理的普遍特征，即最近的经验塑造未来的反应。小鼠初级视觉皮层（V1）对近期经验特别敏感，短暂的刺激可以抑制随后几秒钟的反应。这种快速适应深刻地影响了感知，这表明其影响沿着视觉层次结构传播。为了了解快速适应如何影响感觉处理，我们在视觉系统的关键节点测量了其影响：在 V1 中，三个较高的视觉区域（HVAs：中侧、前外侧和后内侧）以及清醒小鼠的上丘（SC）使用单细胞记录。与适应沿着视觉层次结构的前馈传播一致，我们发现 V1 中各层的神经元适应能力比其他层的神经元弱。此外，HVAs 中的神经元比 V1 中的神经元适应能力更强，恢复速度更慢。HVAs 和 SC 中的适应幅度和时间过程相似，这表明适应可能不会在线性沿前馈视觉处理层次结构累积。尽管与 V1 相比，HVAs 中的适应能力增强，但在所有区域中，适应效果都具有相似的方向特异性。这些数据表明，适应深刻地塑造了皮层处理，在皮层层次结构的更高水平上产生的影响更大，并且强烈影响 SC 中的计算。因此，我们发现快速适应对感觉处理具有强大的、全脑范围的影响。快速适应动态改变感觉信号以适应最近的经验。为了了解适应如何影响感觉处理和感知，我们必须确定它如何影响沿着小鼠视觉系统层次结构的各种皮层和皮层下区域。我们发现，快速适应强烈影响初级视觉皮层、高级视觉区域和丘脑中的神经元，这与它对行为的深远影响一致。
