title: Effects of argon laser irradiation on polar excitations in frog sciatic nerve.
abstract: OBJECTIVE
  Since the mechanisms underlying the effects of low-power laser irradiation on the nervous system remain unclear, we examined whether such irradiation can influence ionic channels of the nerve membrane using the law of polar excitation in isolated frog sciatic nerve.
  
  
  METHODS
  Using 43 frogs (Xenopus laevis), nerve preparations were stimulated at 0.5/second using a 10-millisecond pulse at supramaximal intensity. Ar+ laser irradiation (457, 488, 514 nm; 50, 75, 100 mW) was applied for 30 minutes to the portion between the anode and cathode stimulating electrodes.
  
  
  CONCLUSIONS
  Ar+ laser irradiations (457, 488 nm; 50 mW) blocked the generation of anode-break-excitation, rather than cathode-make-excitation. Such a selective effect occurred when applying a blocker of hyperpolarization-activated cation current (Ih) channel, ZD7288. Ar+ laser irradiation may influence Na+ channels in addition to Ih channels.
authors.affiliation: Department of Bioengineering, Faculty of Engineering, Soka University, Hachioji, Tokyo, 192-8577, Japan. ymatsuda@t.soka.ac.jp
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Matsuda
authors.forename: Mayuka
authors.initials: M
authors.lastname: Niwa
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Iwai
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kogure
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Honjoe
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Komatsu
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ishii
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D000200:Action Potentials / Q000528:radiation effects*; D000818:Animals; D001128:Argon; D004558:Electric Stimulation; D004594:Electrophysiology; D007834:Lasers; D012584:Sciatic Nerve / Q000502:physiology* / Q000528:radiation effects*; D014982:Xenopus laevis
chemical_list: D001128:Argon