Jiang Xuliang, Wen Xin, Ou Guoyao, Li Shitong, Chen Yali, Zhang Jun, Liang Zhenhu
Department of Anesthesiology, Shanghai Cancer Center, Fudan University, Shanghai, 200032 People's Republic of China.
Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032 People's Republic of China.
Cogn Neurodyn. 2023 Dec;17(6):1541-1559. doi: 10.1007/s11571-022-09912-0. Epub 2022 Nov 22.
The thalamocortical system plays an important role in consciousness. How anesthesia modulates the thalamocortical interactions is not completely known. We simultaneously recorded local field potentials(LFPs) in thalamic reticular nucleus(TRN) and ventroposteromedial thalamic nucleus(VPM), and electrocorticographic(ECoG) activities in frontal and occipital cortices in freely moving rats ( = 11). We analyzed the changes in thalamic and cortical local spectral power and connectivities, which were measured with phase-amplitude coupling (PAC), coherence and multivariate Granger causality, at the states of baseline, intravenous infusion of propofol 20, 40, 80 mg/kg/h and after recovery of righting reflex. We found that propofol-induced burst-suppression results in a synchronous decrease of spectral power in thalamus and cortex ( < 0.001 for all frequency bands). The cross-frequency PAC increased by propofol, characterized by gradually stronger 'trough-max' pattern in TRN and stronger 'peak-max' pattern in cortex. The cross-region PAC increased in the phase of TRN modulating the amplitude of cortex. The functional connectivity (FC) between TRN and cortex for α/β bands also significantly increased (< 0.040), with increased directional connectivity from TRN to cortex under propofol anesthesia. In contrast, the corticocortical FC significantly decreased ( < 0.047), with decreased directional connectivity from frontal cortex to occipital cortex. However, the thalamothalamic functional and directional connectivities remained largely unchanged by propofol anesthesia. The spectral powers and connectivities are differentially modulated with the changes of propofol doses, suggesting the changes in neural dynamics in thalamocortical system could be used for distinguishing different vigilance levels caused by propofol.
The online version contains supplementary material available at 10.1007/s11571-022-09912-0.
丘脑皮质系统在意识中起着重要作用。麻醉如何调节丘脑皮质相互作用尚不完全清楚。我们在自由活动的大鼠（n = 11）中同时记录丘脑网状核（TRN）和丘脑腹后内侧核（VPM）的局部场电位（LFP），以及额叶和枕叶皮质的脑电活动（ECoG）。我们分析了在基线、静脉输注丙泊酚20、40、80mg/kg/h以及翻正反射恢复状态下，通过相位-幅度耦合（PAC）、相干性和多变量格兰杰因果关系测量的丘脑和皮质局部频谱功率及连接性的变化。我们发现，丙泊酚诱导的爆发抑制导致丘脑和皮质频谱功率同步下降（所有频段P < 0.001）。丙泊酚使交叉频率PAC增加，其特征是TRN中“谷-峰”模式逐渐增强，皮质中“峰-峰”模式增强。在TRN调节皮质幅度的阶段，跨区域PAC增加。TRN与皮质之间α/β频段的功能连接（FC）也显著增加（P < 0.040），在丙泊酚麻醉下从TRN到皮质的定向连接增加。相反，皮质-皮质FC显著降低（P < 0.047），从额叶皮质到枕叶皮质的定向连接减少。然而，丙泊酚麻醉对丘脑-丘脑功能和定向连接性影响不大。频谱功率和连接性随丙泊酚剂量变化而受到不同调节，表明丘脑皮质系统神经动力学变化可用于区分丙泊酚引起的不同警觉水平。
在线版本包含可在10.1007/s11571-022-09912-0获取的补充材料。
