title: Local field potential recordings in a non-human primate model of Parkinsons disease using the Activa PC + S neurostimulator.
abstract: OBJECTIVE
  Using the Medtronic Activa® PC + S system, this study investigated how passive joint manipulation, reaching behavior, and deep brain stimulation (DBS) modulate local field potential (LFP) activity in the subthalamic nucleus (STN) and globus pallidus (GP).
  
  
  METHODS
  Five non-human primates were implanted unilaterally with one or more DBS leads. LFPs were collected in montage recordings during resting state conditions and during motor tasks that facilitate the expression of parkinsonian motor signs. These recordings were made in the naïve state in one subject, in the parkinsonian state in two subjects, and in both naïve and parkinsonian states in two subjects.
  
  
  RESULTS
  LFPs measured at rest were consistent over time for a given recording location and parkinsonian state in a given subject; however, LFPs were highly variable between subjects, between and within recording locations, and across parkinsonian states. LFPs in both naïve and parkinsonian states across all recorded nuclei contained a spectral peak in the beta band (10-30 Hz). Moreover, the spectral content of recorded LFPs was modulated by passive and active movement of the subjects' limbs. LFPs recorded during a cued-reaching task displayed task-related beta desynchronization in STN and GP. The bidirectional capabilities of the Activa® PC + S also allowed for recording LFPs while delivering DBS. The therapeutic effect of STN DBS on parkinsonian rigidity outlasted stimulation for 30-60 s, but there was no correlation with beta band power.
  
  
  CONCLUSIONS
  This study emphasizes (1) the variability in spontaneous LFPs amongst subjects and (2) the value of using the Activa® PC + S system to record neural data in the context of behavioral tasks that allow one to evaluate a subject's symptomatology.
authors.affiliation: Department of Biomedical Engineering, University of Minnesota, USA.
authors.forename: Allison T
authors.initials: AT
authors.lastname: Connolly
authors.forename: Abirami
authors.initials: A
authors.lastname: Muralidharan
authors.forename: Claudia
authors.initials: C
authors.lastname: Hendrix
authors.forename: Luke
authors.initials: L
authors.lastname: Johnson
authors.forename: Rahul
authors.initials: R
authors.lastname: Gupta
authors.forename: Scott
authors.initials: S
authors.lastname: Stanslaski
authors.forename: Tim
authors.initials: T
authors.lastname: Denison
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Baker
authors.forename: Jerrold L
authors.initials: JL
authors.lastname: Vitek
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Johnson
mesh_terms: D000818:Animals; D046690:Deep Brain Stimulation / Q000295:instrumentation / Q000379:methods*; D004195:Disease Models, Animal; D005260:Female; D008253:Macaca mulatta; D010300:Parkinson Disease / Q000503:physiopathology* / Q000628:therapy*; D011323:Primates