title: Microsurgical access for cell injection into the mammalian cochlea.
abstract: The potential use of stem cells to repair hearing loss requires surgical access to the cochlea. Here we describe a microsurgical technique for cell injection into the mouse cochlea. Green fluorescent cells (ZsGreen-MCF10A cells) were successfully injected via a lateral wall cochleostomy into the scala media, scala tympani and scala vestibuli compartments of the cochlea. The effect of surgery on auditory function was investigated with auditory brainstem responses (ABR) to click and tone stimuli. A computerised signal-to-noise ratio detection method was developed to measure ABR thresholds in conjunction with visual inspection. Signal-to-noise ratio detection showed ABR thresholds in control mice were similar for click (33+/-7 dB) and tone stimuli (33+/-6 dB), in agreement with visual inspection (click 39+/-7 dB, tone 35+/-6 dB). The mean ABR threshold for combined click and tone stimuli was 15-45 dB greater after surgery with minimum hearing loss achieved with a small sized cochleostomy (< or =0.4mm) and by sibling matching to control mice (control 33+/-4 dB, surgery 48+/-3 dB). The microsurgical technique will provide a basis for future studies on the use of stem cells in the treatment of hearing loss.
authors.affiliation: ENT Department, St. Vincent's Hospital, Sydney, NSW 2010, Australia.
authors.forename: Sofie
authors.initials: S
authors.lastname: Bogaerts
authors.forename: Susan
authors.initials: S
authors.lastname: Douglas
authors.forename: Toby
authors.initials: T
authors.lastname: Corlette
authors.forename: Henry
authors.initials: H
authors.lastname: Pau
authors.forename: Darren
authors.initials: D
authors.lastname: Saunders
authors.forename: Sarah
authors.initials: S
authors.lastname: McKay
authors.forename: Sharon
authors.initials: S
authors.lastname: Oleskevich
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D000831:Animals, Newborn; D017690:Cell Transplantation / Q000379:methods*; D003051:Cochlea / Q000166:cytology* / Q000601:surgery*; D004569:Electroencephalography; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008808:Mice, Inbred CBA; D008866:Microsurgery / Q000379:methods*
chemical_list: D049452:Green Fluorescent Proteins