Razi Farhad, Sancristóbal Belén
Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.
Computational Biology and Complex Systems Group, Department of Physics, Universitat Politècnica de Catalunya, Barcelona, Spain.
PLoS Comput Biol. 2025 Aug 18;21(8):e1013398. doi: 10.1371/journal.pcbi.1013398. eCollection 2025 Aug.
Perceptual awareness of auditory stimuli decreases from wakefulness to sleep, largely due to reduced cortical responsiveness. During wakefulness, neural responses to external stimuli in most cortical areas exhibit a broader spatiotemporal propagation pattern compared to deep sleep. A potential mechanism for this phenomenon is the synaptic upscaling of cortical excitatory connections during wakefulness, as posited by the synaptic homeostasis hypothesis. However, we argue that uniform synaptic upscaling alone cannot fully account for this observation. We propose a novel mechanism suggesting that the upscaling of excitatory connections between different cortical areas exceeds that within individual cortical areas during wakefulness. Our computational results demonstrate that the former promotes the transfer of neural responses and information, whereas the latter has diminishing effects. These findings highlight the necessity of heterogeneous synaptic upscaling and suggest the presence of heterogeneity in receptor expression for neuromodulators involved in synaptic modulation along the dendrite.
对听觉刺激的感知意识从清醒状态到睡眠状态会降低，这主要是由于皮层反应性降低所致。在清醒状态下，与深度睡眠相比，大多数皮层区域对外部刺激的神经反应表现出更广泛的时空传播模式。正如突触稳态假说所提出的，这种现象的一个潜在机制是清醒状态下皮层兴奋性连接的突触增强。然而，我们认为仅均匀的突触增强不能完全解释这一观察结果。我们提出了一种新机制，表明在清醒状态下不同皮层区域之间兴奋性连接的增强超过了单个皮层区域内的增强。我们的计算结果表明，前者促进神经反应和信息的传递，而后者的作用则逐渐减弱。这些发现突出了异质性突触增强的必要性，并表明在沿树突参与突触调制的神经调质受体表达中存在异质性。
