title: Robust deep brain stimulation functional MRI procedures in rats and mice using an MR-compatible tungsten microwire electrode.
abstract: OBJECTIVE
  To develop a series of robust and readily adoptable protocols for the application of deep brain stimulation (DBS)-functional MRI (fMRI) in rodents.
  
  
  METHODS
  DBS-fMRI procedures were conducted in rat and mouse under varying anesthetic conditions (isoflurane in rat and mouse, α-chloralose in rat). A homemade two-channel tungsten microwire electrode was used to minimize magnetic susceptibility artifacts, and was targeted to the ventral posteromedial (VPM) thalamus for DBS-fMRI scanning procedures.
  
  
  RESULTS
  Compared with a commercially available MR-compatible electrode, the tungsten microwire generated greatly reduced magnetic-susceptibility artifacts. In the rat, VPM-DBS using the microwire electrode resulted in robust positive blood-oxygen-level-dependent signal changes in somatosensory cortex that were relatively independent of anesthetic type. In the mouse, VPM-DBS similarly generated large, positive neurovascular responses in somatosensory cortex that were detected using cerebral blood volume measurements.
  
  
  CONCLUSIONS
  Collectively, this work describes reasonable and easily adoptable procedures for conducting DBS-fMRI studies in rodent models. The protocols developed herein may be extended to study DBS effects under numerous experimental conditions and at varying stimulation targets.
authors.affiliation: Department of Neurology, University of North Carolina, Chapel Hill, North Carolina, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina, USA.
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Lai
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Albaugh
authors.forename: Yu-Chieh Jill
authors.initials: YC
authors.lastname: Kao
authors.forename: John R
authors.initials: JR
authors.lastname: Younce
authors.forename: Yen-Yu Ian
authors.initials: YY
authors.lastname: Shih
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005071:Evoked Potentials / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D008839:Microelectrodes; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014414:Tungsten
chemical_list: D001672:Biocompatible Materials; D014414:Tungsten
keywords: deep brain stimulation; fMRI; mouse; rat; tungsten electrode