title: [Effects of laser-assisted cochleostomy on inner hair cell ribbon synapse in rats].
abstract: OBJECTIVE
  To investigate the effects on ribbon synapse of inner hair cells after superpulsed CO2 laser-assisted cochleostomy in SD rats.
  
  
  METHODS
  Eighteen SD rats were randomly divided into laser-assisted surgery groups (2 W group and 5 W group), sham-operated group and control group. Ten of those were performed a cochleostomy using superpulsed CO2 laser with a corresponding power. Auditory brainstem responses (ABR) were measured pre-and postoperatively. The ribbon synapses at apical and middle cochlear turns were observed under laser scanning confocal microscope and then were quantified with 3ds Max software.
  
  
  RESULTS
  The postoperative ABR thresholds of the 2 W and 5 W groups were larger than the preoperative case (t = -5.65, P < 0.01; t = -4.97, P < 0.01). The synapse number at the middle turn decreased significantly in 5 W group (F = 17.15, P < 0.01), while no significant changes were noted at the apical turn (P > 0.05). There was no statistical difference in 2 W group (P > 0.05).
  
  
  CONCLUSIONS
  The superpulsed CO2 laser-assisted cochleostomy with high-power is accompanied by a synaptic injury, while no obvious effects after the low-power laser surgery, which might be a safe strategy to preform cochleostomy.
authors.affiliation: Department of Otorhinolaryngology, Provincial Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fujian Geriatric Hospital, Fuzhou 350001, China. yeqing180302@yahoo.com.cn
authors.forename: Qing
authors.initials: Q
authors.lastname: Ye
authors.forename: Yang
authors.initials: Y
authors.lastname: Geng
authors.forename: Xian-zeng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Shuang-mu
authors.initials: SM
authors.lastname: Zhuo
authors.forename: Tian-jie
authors.initials: TJ
authors.lastname: Tian
authors.forename: Shu-sen
authors.initials: SS
authors.lastname: Xie
mesh_terms: D000818:Animals; D003051:Cochlea / Q000601:surgery*; D006199:Hair Cells, Auditory, Inner / Q000528:radiation effects*; D053685:Laser Therapy; D054020:Lasers, Gas / Q000009:adverse effects*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000528:radiation effects*