title: Isoflurane, but Not the Nonimmobilizers F6 and F8, Inhibits Rat Spinal Cord Motor Neuron CaV1 Calcium Currents.
abstract: BACKGROUND
  Volatile anesthetics decrease Ca²⁺ entry through voltage-dependent Ca²⁺ channels. Ca influences neurotransmitter release and neuronal excitability. Because volatile anesthetics act specifically on the spinal cord to produce immobility, we examined the effect of isoflurane and the nonimmobilizers F6 (1, 2-dichlorohexafluorocyclobutane) and F8 (2, 3-dichlorooctafluorobutane) on CaV1 and CaV2 Ca²⁺ channels in spinal cord motor neurons and dorsal root ganglion neurons.
  
  
  METHODS
  Using patch clamping, we compared the effects of isoflurane with those of F6 and F8 on CaV1 and CaV2 channels in isolated, cultured adult rat spinal cord motor neurons and on CaV1 and CaV2 channels in adult rat dorsal root ganglion sensory neurons.
  
  
  RESULTS
  In spinal cord motor neurons, isoflurane, but not F6 or F8, inhibited currents through CaV1 channels. Isoflurane and at least one of the nonimmobilizers inhibited currents through CaV1 and CaV2 channels in dorsal root ganglion neurons and CaV2 in spinal cord motor neurons.
  
  
  CONCLUSIONS
  The findings that isoflurane, but not nonimmobilizers, inhibited CaV1 Ca²⁺ channels in spinal cord motor neurons are consistent with the notion that spinal cord motor neurons might mediate isoflurane-induced immobility. Additional studies are required to examine whether inhibition of CaV1 calcium currents in spinal cord motor neurons is sufficient or whether actions on other channels/proteins contribute to isoflurane-induced immobility.
authors.affiliation: From the Department of Anesthesiology, NYU Langone Medical Center, New York, New York.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Recio-Pinto
authors.forename: Jose V
authors.initials: JV
authors.lastname: Montoya-Gacharna
authors.forename: Fang
authors.initials: F
authors.lastname: Xu
authors.forename: Thomas J J
authors.initials: TJJ
authors.lastname: Blanck
mesh_terms: D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D020746:Calcium Channels, L-Type / Q000187:drug effects*; D017402:Chlorofluorocarbons / Q000494:pharmacology*; D003503:Cyclobutanes / Q000494:pharmacology*; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects; D007530:Isoflurane / Q000494:pharmacology*; D009046:Motor Neurons / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D061251:Primary Cell Culture; D051381:Rats; D017207:Rats, Sprague-Dawley; D011984:Sensory Receptor Cells / Q000187:drug effects; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects*
chemical_list: D018685:Anesthetics, Inhalation; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D017402:Chlorofluorocarbons; D003503:Cyclobutanes; C100837:2,3-dichlorooctafluorobutane; C090640:1,2-dichloro-1,2,3,3,4,4-hexafluorocyclobutane; D007530:Isoflurane