A Study Of Selective Action Mechanism And Individual Sensitivity For Propofol Based On EEG Source Reconstruction Analysis

Although the mechanism of general anesthesia at the molecular level research has gained great progress,its mechanism on human central nervous system is still not clear,anesthetic effect on the thalamus or cerebral cortex is still one of the hot issues of academic debate.Mismatch negativity(MMN)is an event related potential(ERP)that reflects the automatic processing and attention switching,has been widely used to study the processing of sensory information under anesthesia in brain.The generators of MMN,however still not settled.Therefore,it is important to find the exact generators of MMN,regardless of the selective mechanism of anesthesia,or to the understanding of the generation mechanism of MMN itself has very important significance.Because of the differences of individual sensitivity to anesthesia,it is easy to cause excessive or intraoperative anesthetic awakening phenomenon,cause damage to the body,so it is very important to explore the reasons for the differences on anesthesia.There are two sets of data in this work,the first set of data was acquired from the First Affiliated Hospital of Xi 'an Jiao Tong University,the infusion of propofol was administrated by a target-controlled infusion device(TCI),the depth of anesthesia was defined according to BIS value,the EEG data during MMN paradigm was acquired at three level of anesthesia.Using this set of data,we first compared the influences of anesthesia on the cortical brain network induced by the two kinds of stimuli in MMN to find the generators of MMN.Secondly,we compared the changes in the cerebral cortex network of the subjects with deepening of the anesthesia through EEG traceability network construction,thereby exploring the selective effect of propofol anesthesia on the central nervous system;The second set of data was from the University of Cambridge Data Repository.The EEG data were obtained from two groups of subjects with different sensitivity to propofol anesthesia when they were under awake,mildly sedation,moderately sedation and recovery respectively.Using the method of source reconstruction analysis,we extracted the activation pattern of the cortical function network,and compared and analyzed the similarities and differences in the functional subnetworks of the two groups of subjects under various anesthesia conditions,to find out the reasons for their difference sensitivity in propofol anesthesia.The results showed that,in the study of the source of MMN production,we observed that the production of MMN requires information exchange among bilateral temporal lobe,prefrontal and central-parietal regions.In the study of propofol anesthesia on the central nervous system selective effect,under the mild anesthesia,the frontal cortex and the primary sensory cortex of the temporal lobe were inhibited at the same time,and there was no observed the order of inhibition of the two.The reason may be that propofol directly acts on the thalamus,so that the auditory information cannot be transmitted to the cortex,or it may be due to the deeper anesthesia of our mild anesthesia.In the study of anesthesia sensitivity,we found that subjects with lower sensitivity to propofol anesthesia had significantly stronger connection strength between the salient network,executive control network and other functional networks in the moderate sedation than the subjects with higher sensitivity,so they can maintain a high response in moderate sedation.Moreover,in the awake state,the connection strength of salient network in the brain network with lover sensitivity is higher than that of the higher sensitive groups,so we hypothesize that the salient network is the key to guaranteeing network robustness and affecting the sensitivity of anesthesia.Our results can provide a deeper understanding of the selective mechanisms of propofol anesthesia and the process of processing perceptual information,and provide assistance for the safe use of surgical anesthesia.