title: Orientation selective deep brain stimulation.
abstract: Target selectivity of deep brain stimulation (DBS) therapy is critical, as the precise locus and pattern of the stimulation dictates the degree to which desired treatment responses are achieved and adverse side effects are avoided. There is a clear clinical need to improve DBS technology beyond currently available stimulation steering and shaping approaches. We introduce orientation selective neural stimulation as a concept to increase the specificity of target selection in DBS.
  
  
  
  This concept, which involves orienting the electric field along an axonal pathway, was tested in the corpus callosum of the rat brain by freely controlling the direction of the electric field on a plane using a three-electrode bundle, and monitoring the response of the neurons using functional magnetic resonance imaging (fMRI). Computational models were developed to further analyze axonal excitability for varied electric field orientation.
  
  
  
  Our results demonstrated that the strongest fMRI response was observed when the electric field was oriented parallel to the axons, while almost no response was detected with the perpendicular orientation of the electric field relative to the primary fiber tract. These results were confirmed by computational models of the experimental paradigm quantifying the activation of radially distributed axons while varying the primary direction of the electric field.
  
  
  
  The described strategies identify a new course for selective neuromodulation paradigms in DBS based on axonal fiber orientation.
authors.affiliation: Center for Magnetic Resonance Research, Radiology, University of Minnesota, 2021 6th St SE, Minneapolis, MN 55455, USA.
authors.forename: Lauri J
authors.initials: LJ
authors.lastname: Lehto
authors.forename: Julia P
authors.initials: JP
authors.lastname: Slopsema
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Johnson
authors.forename: Artem
authors.initials: A
authors.lastname: Shatillo
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Teplitzky
authors.forename: Lynn
authors.initials: L
authors.lastname: Utecht
authors.forename: Gregor
authors.initials: G
authors.lastname: Adriany
authors.forename: Silvia
authors.initials: S
authors.lastname: Mangia
authors.forename: Alejandra
authors.initials: A
authors.lastname: Sierra
authors.forename: Walter C
authors.initials: WC
authors.lastname: Low
authors.forename: Olli
authors.initials: O
authors.lastname: Gröhn
authors.forename: Shalom
authors.initials: S
authors.lastname: Michaeli
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000465:Algorithms; D000818:Animals; D016880:Anisotropy; D001931:Brain Mapping / Q000379:methods*; D003337:Corpus Callosum / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013813:Therapy, Computer-Assisted / Q000379:methods*