Recent studies suggest that vagus nerve stimulation (VNS) promotes cognitive and behavioral restoration after traumatic brain injuries. As vagus nerve has wide effects over the brain and visceral organs, stimulation of the sensory/visceral afferents might have a therapeutic potential to modulate the level of consciousness. One of the most important challenges in studying consciousness is objective evaluation of the consciousness level. Brain complexity that can be measured through Lempel-Ziv complexity (LZC) index was used as a novel mathematical approach for objective measurement of consciousness. The main goal of our study was to examine the effects of VNS on LZC index of consciousness. In this study, we did VNS on the anesthetized rats, and simultaneously LFPs recording was performed in two different cortical areas of primary somatosensory (S₁) or visual (V₁) cortex. LZC and the amplitude of slow waves were computed during different periods of VNS. We found that the LZC index during VNS period was significantly higher in both of the cortical areas of S₁ and V₁. Slow-wave activity decreased during VNS in S₁, while there was no significant change in V₁. Our findings showed that VNS can augment the consciousness level, and LZC index is a more sensitive parameter for detecting the level of consciousness.

最近的研究表明，迷走神经刺激 (VNS) 可促进创伤性脑损伤后的认知和行为恢复。由于迷走神经对大脑和内脏器官有广泛的影响，刺激感觉/内脏传入可能具有调节意识水平的治疗潜力。研究意识的最重要挑战之一是对意识水平的客观评估。可以通过 Lempel-Ziv 复杂性 (LZC) 指数测量的大脑复杂性被用作客观测量意识的新数学方法。我们研究的主要目标是检查 VNS 对 LZC 意识指数的影响。在这项研究中，我们对麻醉的大鼠进行了 VNS，同时在初级体感的两个不同皮质区域（S₁ ) 或视觉 (V ₁ ) 皮层。LZC 和慢波的振幅是在 VNS 的不同时期计算的。我们发现 VNS 期间的 LZC 指数在 S ₁和 V _{1 的}两个皮质区域均显着较高。慢波活动在S _{1 的}VNS 期间降低，而V ₁没有显着变化。我们的研究结果表明，VNS 可以增强意识水平，而 LZC 指数是检测意识水平的更敏感参数。