title: Activity in the brain network for dynamic manipulation of unstable objects is robust to acute tactile nerve block: An fMRI study.
abstract: OBJECTIVE
  To study whether a temporary block of the tactile afferents from the fingers causes altered activity in the neural network for dexterous manipulation.
  
  
  METHODS
  Whole-brain functional Magnetic Resonance Imaging (fMRI) was conducted in 18 healthy subjects, while they compressed an unstable spring between the thumb and index finger of the right hand. Two sensory conditions--with and without tactile input from the fingers--were employed. In the latter condition the digital nerves were blocked by local anesthesia.
  
  
  RESULTS
  Compression of the unstable spring was associated with activity in an earlier described network for object manipulation. We found that this entire network remained active after a nerve block, and the activity was increased in the dorsal premotor cortex.
  
  
  CONCLUSIONS
  The neural network for dexterous manipulation is robust with only minor alterations after acute loss of tactile information from the fingers. There was no loss of activity, but, unexpectedly, an increased activity in some parts of the network.
  
  
  CONCLUSIONS
  This study gives new insights to possible neural compensatory mechanisms that make fine motor control possible after acute disruption of tactile information in natural situations like cold weather or wearing surgical gloves.
authors.affiliation: Department of Rehabilitation Medicine, Danderyd University Hospital, 18288 Stockholm, Sweden; Department of Clinical Sciences, Karolinska Institute, 18288 Stockholm, Sweden. Electronic address: Elena.Pavlova@ki.se.
authors.forename: Elena
authors.initials: E
authors.lastname: Pavlova
authors.affiliation: Department of Women׳s and Children׳s Health, Neuropediatric Research Unit, Karolinska Institute, 17176 Stockholm, Sweden; Stockholm Brain Institute, Karolinska Institute, 17176 Stockholm, Sweden.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Hedberg
authors.affiliation: Department of Women׳s and Children׳s Health, Neuropediatric Research Unit, Karolinska Institute, 17176 Stockholm, Sweden; Department of Pediatric Orthopedic Surgery, Astrid Lindgren Children׳s Hospital, Karolinska University Hospital, 17176 Stockholm, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Ponten
authors.affiliation: Department of Women׳s and Children׳s Health, Neuropediatric Research Unit, Karolinska Institute, 17176 Stockholm, Sweden; Department of Pediatric Orthopedic Surgery, Astrid Lindgren Children׳s Hospital, Karolinska University Hospital, 17176 Stockholm, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Gantelius
authors.affiliation: Department of Biomedical Engineering, and Division of Biokinesiology & Physical Therapy, University of Southern California, Los Angeles, CA, USA.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Valero-Cuevas
authors.affiliation: Department of Women׳s and Children׳s Health, Neuropediatric Research Unit, Karolinska Institute, 17176 Stockholm, Sweden; Stockholm Brain Institute, Karolinska Institute, 17176 Stockholm, Sweden.
authors.forename: Hans
authors.initials: H
authors.lastname: Forssberg
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000494:pharmacology; D001931:Brain Mapping; D005260:Female; D005385:Fingers / Q000502:physiology*; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009407:Nerve Block; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D014110:Touch / Q000187:drug effects / Q000502:physiology*; D055698:Touch Perception / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local
keywords: Dorsal premotor cortex; Local anesthesia; Manipulation task; Motor task; Spring compression test; fMRI