Hwang, E. McNally, J.M. Choi, J.H. 2024-01-20T11:01:39Z 2024-01-20T11:01:39Z 2022-01-10 2013-12 1662-5137 https://pubs.kist.re.kr/handle/201004/127361 EEG gamma band oscillations have been proposed to account for the neural synchronization crucial for perceptual integration. While increased gamma power and synchronization is generally observed during cognitive tasks performed during wake, several studies have additionally reported increased gamma power during sleep or anesthesia, raising questions about the characteristics of gamma oscillation during impaired consciousness and its role in conscious processing. Phase-amplitude modulation has been observed between slow wave activity (SWA, 0.5-4 Hz) and gamma oscillations during ketamine/xylazine anesthesia or sleep, showing increased gamma activity corresponding to the depolarized (ON) state of SWA. Here we divided gamma activity into its ON and OFF (hyperpolarized) state components based on the phase of SWA induced by ketamine/xylazine anesthesia and compared their power and synchrony with wake state levels in mice. We further investigated the state-dependent changes in both gamma power and synchrony across primary motor and primary somatosensory cortical regions and their interconnected thalamic regions throughout anesthesia and recovery. As observed previously, gamma power was as high as during wake specifically during the ON state of SWA. However, the synchrony of this gamma activity between somatosensory-motor cortical regions was significantly reduced compared to the baseline wake state. In addition, the somatosensory-motor cortical synchrony of gamma oscillations was reduced and restored in an anesthetic state-dependent manner, reflecting the changing depth of anesthesia. Our results provide evidence that during anesthesia changes in long-range information integration between cortical regions might be more critical for changes in consciousness than changes in local gamma oscillatory power. ？ 2013 Hwang, McNally and Choi. English ketamine xylazine amplitude modulation animal experiment article depolarization electroencephalography electroencephalography phase synchronization Fourier transformation frequency modulation frontal cortex gamma rhythm hyperpolarization male motor cortex mouse nonhuman oscillation parietal cortex primary somatosensory cortex sleep sleep waking cycle slow brain wave somatosensory cortex thalamocortical tract thalamus nucleus wakefulness walking Reduction in cortical gamma synchrony during depolarized state of slow wave activity in mice Article 10.3389/fnsys.2013.00107 1 Frontiers in Systems Neuroscience, v.7, no.DEC Frontiers in Systems Neuroscience 7 DEC scopus 2-s2.0-84890842444 Article ketamine xylazine amplitude modulation animal experiment article depolarization electroencephalography electroencephalography phase synchronization Fourier transformation frequency modulation frontal cortex gamma rhythm hyperpolarization male motor cortex mouse nonhuman oscillation parietal cortex primary somatosensory cortex sleep sleep waking cycle slow brain wave somatosensory cortex thalamocortical tract thalamus nucleus wakefulness walking Electroencephalography (EEG) Gamma oscillations Ketamine anaesthesia Local field potential (LFP) Phase synchronization Slow wave activity