title: Botulinum toxin-induced focal paresis in mice is unaffected by muscle activity.
abstract: BACKGROUND
  To test the hypothesis that the efficacy of botulinum toxin depends on the activity of the neuromuscular junction, we developed an in vivo paradigm to determine the degree and duration of low-dose botulinum toxin-induced focal paresis in mice.
  
  
  METHODS
  We combined an automated wheel-running paradigm with low-dose botulinum toxin injections into the calf muscles of wild-type mice. Half of the mice were injected either before the nightly running or before the daily resting period.
  
  
  RESULTS
  After botulinum toxin injections, running distance and maximum velocity decreased dose-dependently. The degree and duration of decrease between the respective groups with regard to the time-points of injection were identical.
  
  
  CONCLUSIONS
  This in vivo paradigm quantifies the degree of otherwise clinically inapparent botulinum toxin-induced focal calf muscle paresis. Increased muscle activity after low-dose injections does not influence the efficacy of botulinum toxin in normal muscles.
authors.affiliation: Department of Clinical Neurophysiology, University Medical Centre Göttingen, Göttingen, Germany. anna.kutschenko@med.uni-goettingen.de
authors.forename: Anna
authors.initials: A
authors.lastname: Kutschenko
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Reinert
authors.forename: Florian
authors.initials: F
authors.lastname: Klinker
authors.forename: Walter
authors.initials: W
authors.lastname: Paulus
authors.forename: Stefan
authors.initials: S
authors.lastname: Hesse
authors.forename: David
authors.initials: D
authors.lastname: Liebetanz
mesh_terms: D000818:Animals; D001905:Botulinum Toxins / Q000633:toxicity*; D005080:Exercise Test / Q000187:drug effects / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology; D010291:Paresis / Q000139:chemically induced* / Q000503:physiopathology*; D011897:Random Allocation; D012420:Running / Q000502:physiology*
chemical_list: D001905:Botulinum Toxins