title: Measuring complex behaviors of local oscillatory networks in deep brain local field potentials.
abstract: BACKGROUND
  Multiple oscillations emerging from the same neuronal substrate serve to construct a local oscillatory network. The network usually exhibits complex behaviors of rhythmic, balancing and coupling between the oscillations, and the quantification of these behaviors would provide valuable insight into organization of the local network related to brain states.
  
  
  METHODS
  An integrated approach to quantify rhythmic, balancing and coupling neural behaviors based upon power spectral analysis, power ratio analysis and cross-frequency power coupling analysis was presented. Deep brain local field potentials (LFPs) were recorded from the thalamus of patients with neuropathic pain and dystonic tremor. t-Test was applied to assess the difference between the two patient groups.
  
  
  RESULTS
  The rhythmic behavior measured by power spectral analysis showed significant power spectrum difference in the high beta band between the two patient groups. The balancing behavior measured by power ratio analysis showed significant power ratio differences at high beta band to 8-20 Hz, and 30-40 Hz to high beta band between the patient groups. The coupling behavior measured by cross-frequency power coupling analysis showed power coupling differences at (theta band, high beta band) and (45-55 Hz, 70-80 Hz) between the patient groups.
  
  
  CONCLUSIONS
  The study provides a strategy for studying the brain states in a multi-dimensional behavior space and a framework to screen quantitative characteristics for biomarkers related to diseases or nuclei.
  
  
  CONCLUSIONS
  The work provides a comprehensive approach for understanding the complex behaviors of deep brain LFPs and identifying quantitative biomarkers for brain states related to diseases or nuclei.
authors.affiliation: Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yongzhi
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China; University of Chinese Academy of Sciences, Beijing 100049, China; Nuffield Department of Surgery, University of Oxford, Oxford OX3 9DU, UK; Department of Neurosurgery, John Radcliffe Hospital, Oxford OX3 9DU, UK.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Geng
authors.affiliation: School of Aerospace Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Luming
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK.
authors.forename: John F
authors.initials: JF
authors.lastname: Stein
authors.affiliation: Nuffield Department of Surgery, University of Oxford, Oxford OX3 9DU, UK; Department of Neurosurgery, John Radcliffe Hospital, Oxford OX3 9DU, UK.
authors.forename: Tipu Z
authors.initials: TZ
authors.lastname: Aziz
authors.affiliation: Nuffield Department of Surgery, University of Oxford, Oxford OX3 9DU, UK; Department of Neurosurgery, John Radcliffe Hospital, Oxford OX3 9DU, UK.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Green
authors.affiliation: Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China. Electronic address: swang@sibet.ac.cn.
authors.forename: Shouyan
authors.initials: S
authors.lastname: Wang
mesh_terms: D000328:Adult; D058256:Brain Waves / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000379:methods*; D004421:Dystonia / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D009437:Neuralgia / Q000503:physiopathology*; D013788:Thalamus / Q000502:physiology*; D014202:Tremor / Q000503:physiopathology*
keywords: Coupling; Cross-frequency; Deep brain stimulation; Synchronization