Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Georgia, USA.
Nat Neurosci. 2010 Dec;13(12):1534-41. doi: 10.1038/nn.2670.
Although it has long been posited that sensory adaptation serves to enhance information flow in sensory pathways, the neural basis remains elusive. Simultaneous single-unit recordings in the thalamus and cortex in anesthetized rats showed that adaptation differentially influenced thalamus and cortex in a manner that fundamentally changed the nature of information conveyed about vibrissa motion. Using an ideal observer of cortical activity, we found that performance in detecting vibrissal deflections degraded with adaptation while performance in discriminating among vibrissal deflections of different velocities was enhanced, a trend not observed in thalamus. Analysis of simultaneously recorded thalamic neurons did reveal, however, an analogous adaptive change in thalamic synchrony that mirrored the cortical response. An integrate-and-fire model using experimentally measured thalamic input reproduced the observed transformations. The results here suggest a shift in coding strategy with adaptation that directly controls information relayed to cortex, which could have implications for encoding velocity signatures of textures.
尽管人们早就假设感觉适应有助于增强感觉通路中的信息流动，但神经基础仍然难以捉摸。在麻醉大鼠的丘脑和皮层同时进行的单细胞记录显示，适应以一种从根本上改变关于触须运动所传达信息性质的方式，对丘脑和皮层产生了不同的影响。使用皮层活动的理想观察者，我们发现，在检测触须偏斜的性能随着适应而降低，而在区分不同速度的触须偏斜的性能则增强，而在丘脑则没有观察到这种趋势。然而，对同时记录的丘脑神经元的分析确实揭示了丘脑同步的类似适应性变化，这种变化反映了皮层的反应。使用实验测量的丘脑输入的积分和点火模型再现了观察到的转换。这里的结果表明，随着适应的编码策略发生转变，这直接控制着传递到皮层的信息，这可能对编码纹理的速度特征有影响。
