title: Neurotransmitter release changes induced by low power 830 nm diode laser irradiation on the neuromuscular junctions of the mouse.
abstract: OBJECTIVE
  Treating patients with a Gallium-Aluminum-Arsenide (GaAlAs) infrared (IR) diode laser reduces muscle spasm and increases mobility in the muscles. The effect of low intensity laser irradiation on nerve function, growth, and repair mechanisms is a contentious area of research. We have addressed one aspect of this controversy by systematically examining the influence of 830 nm laser radiation on neurotransmitter release in neuromuscular junctions (NMJ) of the mouse diaphragm.
  
  
  METHODS
  Thirty adult mice were studied. Diode laser GaAlAs 830 nm (4 and 12 J/cm2) was used. Neurotransmitter release was studied by conventional intracellular recording techniques on curarized muscles or high magnesium media. The quantal content, amplitude, and latency of the end-plate potentials (EPPs) were analyzed. Frequency and amplitude were evaluated for the miniature end-plate potentials (MEPPs). Facilitation of the neurotransmitter release was also evaluated by paired pulse stimulation.
  
  
  CONCLUSIONS
  The irradiated (12 J/cm2) muscles showed a significant reduction in quantal content (P = 0.01) and EPP amplitude (P = 0.04), but the latency, spontaneous transmitter release (MEPPs) and paired pulse facilitation did not change. No alterations were observed in NMJ irradiated with 4 J/cm2. We conclude that 830 nm diode laser irradiation (at a dose of 12 J/cm2) can affect the evoked neurotransmitter release in the mouse motor endplates.
authors.affiliation: Institute for Research and Development (IP&D), Universidade do Vale do Paraíba (Univap)-SJC, Brazil. rani@univap.br
authors.forename: Renata Amadei
authors.initials: RA
authors.lastname: Nicolau
authors.forename: Manel Santafé
authors.initials: MS
authors.lastname: Martinez
authors.forename: Josepa
authors.initials: J
authors.lastname: Rigau
authors.forename: Josep
authors.initials: J
authors.lastname: Tomàs
mesh_terms: D000818:Animals; D019054:Evoked Potentials, Motor / Q000528:radiation effects*; D028022:Low-Level Light Therapy / Q000295:instrumentation*; D008297:Male; D051379:Mice; D009469:Neuromuscular Junction / Q000502:physiology / Q000528:radiation effects*; D018377:Neurotransmitter Agents / Q000096:biosynthesis / Q000528:radiation effects*
chemical_list: D018377:Neurotransmitter Agents