Schmors Lisa, Kotkat Ann H, Bauer Yannik, Huang Ziwei, Crombie Davide, Meyerolbersleben Lukas Sebastian, Sokoloski Sacha, Berens Philipp, Busse Laura
Hertie Institute for AI in Brain Health, University of Tübingen, 72076 Tübingen, Germany.
Division of Neurobiology, Faculty of Biology, LMU Munich, 82152 Planegg-Martinsried, Germany.
iScience. 2025 May 12;28(6):112481. doi: 10.1016/j.isci.2025.112481. eCollection 2025 Jun 20.
In the dorsolateral geniculate nucleus (dLGN) of the thalamus, stimulus-driven signals combine with modulatory inputs such as corticothalamic (CT) feedback and behavioral state, but their impact in shaping dLGN activity is debated. We recorded extracellular responses in the dLGN of mice viewing a movie stimulus, while photosuppressing CT feedback and tracking locomotion and pupil size. Using generalized linear models fit to single neuron responses, we found that including CT feedback and behavioral state improved model predictions, especially for a subpopulation of neurons poorly responsive to the movie. Intriguingly, the impact of CT feedback was stronger without a patterned visual stimulus. Finally, for neurons sensitive to CT feedback, visual stimuli could be more easily discriminated when CT feedback was suppressed. Together, these results show that the effects of modulatory inputs in dLGN depend on visual responsiveness and stimulus type, with CT feedback affecting sensitivity and reliability, potentially to tune the thalamic relay.
在丘脑的背外侧膝状核（dLGN）中，刺激驱动信号与诸如皮质丘脑（CT）反馈和行为状态等调制性输入相结合，但其在塑造dLGN活动方面的影响仍存在争议。我们记录了观看电影刺激的小鼠dLGN中的细胞外反应，同时用光抑制CT反馈并跟踪运动和瞳孔大小。通过将广义线性模型拟合到单个神经元反应，我们发现纳入CT反馈和行为状态可改善模型预测，尤其是对于对电影反应较差的神经元亚群。有趣的是，在没有图案化视觉刺激的情况下，CT反馈的影响更强。最后，对于对CT反馈敏感的神经元，当CT反馈被抑制时，视觉刺激更容易被区分。总之，这些结果表明dLGN中调制性输入的作用取决于视觉反应性和刺激类型，CT反馈影响敏感性和可靠性，可能是为了调节丘脑中继。
