title: Reliability in the location of hindlimb motor representations in Fischer-344 rats: laboratory investigation.
abstract: OBJECTIVE
  The purpose of the present study was to determine the feasibility of using a common laboratory rat strain for reliably locating cortical motor representations of the hindlimb.
  
  
  METHODS
  Intracortical microstimulation techniques were used to derive detailed maps of the hindlimb motor representations in 6 adult Fischer-344 rats.
  
  
  RESULTS
  The organization of the hindlimb movement representation, while variable across individual rats in topographic detail, displayed several commonalities. The hindlimb representation was positioned posterior to the forelimb motor representation and posterolateral to the motor trunk representation. The areal extent of the hindlimb representation across the cortical surface averaged 2.00 ± 0.50 mm(2). Superimposing individual maps revealed an overlapping area measuring 0.35 mm(2), indicating that the location of the hindlimb representation can be predicted reliably based on stereotactic coordinates. Across the sample of rats, the hindlimb representation was found 1.25-3.75 mm posterior to the bregma, with an average center location approximately 2.6 mm posterior to the bregma. Likewise, the hindlimb representation was found 1-3.25 mm lateral to the midline, with an average center location approximately 2 mm lateral to the midline.
  
  
  CONCLUSIONS
  The location of the cortical hindlimb motor representation in Fischer-344 rats can be reliably located based on its stereotactic position posterior to the bregma and lateral to the longitudinal skull suture at midline. The ability to accurately predict the cortical localization of functional hindlimb territories in a rodent model is important, as such animal models are being increasingly used in the development of brain-computer interfaces for restoration of function after spinal cord injury.
authors.affiliation: Department of Molecular & Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Blvd., MS 4016, Kansas City, Kansas 66160, USA. sfrost@kumc.edu
authors.forename: Shawn B
authors.initials: SB
authors.lastname: Frost
authors.forename: Maria
authors.initials: M
authors.lastname: Iliakova
authors.forename: Caleb
authors.initials: C
authors.lastname: Dunham
authors.forename: Scott
authors.initials: S
authors.lastname: Barbay
authors.forename: Paul
authors.initials: P
authors.lastname: Arnold
authors.forename: Randolph J
authors.initials: RJ
authors.lastname: Nudo
mesh_terms: D000818:Animals; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods*; D004558:Electric Stimulation / Q000295:instrumentation / Q000379:methods; D055724:Electrophysiological Phenomena / Q000502:physiology; D005240:Feasibility Studies; D006614:Hindlimb / Q000502:physiology*; D008839:Microelectrodes; D009044:Motor Cortex / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344 / Q000502:physiology*; D012886:Skull / Q000601:surgery