The thalamus is a key element of sensory transmission in the brain, as it gates and selects sensory streams through a modulation of its internal activity. A preponderant role in these functions is played by its internal activity in the alpha range ([8–14] Hz), but the mechanism underlying this process is not completely understood. In particular, how do thalamocortical connections convey stimulus driven information selectively over the back-ground of thalamic internally generated activity? Here we investigate this issue with a spiking network model of feedforward connectivity between thalamus and primary sensory cortex reproducing the local field potential of both areas. We found that in a feedforward network, thalamic oscillations in the alpha range do not entrain cortical activity for two reasons: (i) alpha range oscillations are weaker in neurons projecting to the cortex, (ii) the gamma resonance dynamics of cortical networks hampers oscillations over the 10–20 Hz range thus weakening alpha range oscillations. This latter mechanism depends on the balance of the strength of thalamocortical connections toward excitatory and inhibitory neurons in the cortex. Our results highlight the relevance of corticothalamic feedback to sustain alpha range oscillations and pave the way toward an integrated understanding of the sensory streams traveling between the periphery and the cortex.

丘脑是大脑中感觉传递的关键元素，因为它通过调节其内部活动来控制和选择感觉流。在这些功能中的主要作用是由其在 alpha 范围 ([8-14] Hz) 内的内部活动发挥作用，但这一过程背后的机制尚不完全清楚。特别是，丘脑皮质连接如何在丘脑内部产生的活动的背景下选择性地传递刺激驱动的信息？在这里，我们使用丘脑和初级感觉皮层之间的前馈连接的尖峰网络模型来研究这个问题，该模型再现了这两个区域的局部场电位。我们发现，在前馈网络中，α 范围内的丘脑振荡不会夹带皮层活动，原因有两个：(i) 投射到皮层的神经元的 alpha 范围振荡较弱，(ii) 皮质网络的 gamma 共振动力学阻碍了 10-20 Hz 范围内的振荡，从而削弱了 alpha 范围振荡。后一种机制取决于丘脑皮质连接强度与皮质中兴奋性和抑制性神经元之间的平衡。我们的研究结果强调了皮质丘脑反馈与维持 alpha 范围振荡的相关性，并为全面理解在外围和皮质之间传播的感觉流铺平了道路。后一种机制取决于丘脑皮质连接强度与皮质中兴奋性和抑制性神经元之间的平衡。我们的研究结果强调了皮质丘脑反馈与维持 alpha 范围振荡的相关性，并为全面理解在外围和皮质之间传播的感觉流铺平了道路。后一种机制取决于丘脑皮质连接强度与皮质中兴奋性和抑制性神经元之间的平衡。我们的研究结果强调了皮质丘脑反馈与维持 alpha 范围振荡的相关性，并为全面理解在外围和皮质之间传播的感觉流铺平了道路。