title: FMRI of deep brain stimulation at the rat ventral posteromedial thalamus.
abstract: BACKGROUND
  Functional magnetic resonance imaging (fMRI) of deep brain stimulation (DBS) has potentials to reveal neuroanatomical connectivity of a specific brain region in vivo.
  
  
  OBJECTIVE
  This study aimed to demonstrate frequency and amplitude tunings of the thalamocortical tract using DBS fMRI at the rat ventral posteromedial thalamus.
  
  
  METHODS
  Blood oxygenation level dependent (BOLD) fMRI data were acquired in a total of twelve rats at a high-field 11.7 T MRI scanner with modulation of nine stimulus frequencies (1-40 Hz) and seven stimulus amplitudes (0.2-3.6 mA).
  
  
  RESULTS
  BOLD response in the barrel cortex peaked at 25 Hz. The response increased with stimulus amplitude and reached a plateau at 1 mA. Cortical spreading depolarization (CSD) was observed occasionally after DBS that carries >10% BOLD waves spanning the entire ipsilateral cortex.
  
  
  CONCLUSIONS
  fMRI is sensitive to the frequency effect of DBS and has potential to investigate the function of a particular neuroanatomical pathway.
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Neurology, University of North Carolina, Chapel Hill, NC 27599, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599, USA. Electronic address: shihy@unc.edu.
authors.forename: Yen-Yu Ian
authors.initials: YY
authors.lastname: Shih
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA.
authors.forename: Tiwari V
authors.initials: TV
authors.lastname: Yash
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
authors.forename: Bill
authors.initials: B
authors.lastname: Rogers
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; South Texas Veterans Health Care System, Department of Veterans Affairs, USA. Electronic address: duongt@uthscsa.edu.
authors.forename: Timothy Q
authors.initials: TQ
authors.lastname: Duong
mesh_terms: D000818:Animals; D001931:Brain Mapping; D046690:Deep Brain Stimulation / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013788:Thalamus / Q000502:physiology*
keywords: Deep brain stimulation; Isoflurane; Rat; Striatum; Thalamus; fMRI