GMC17 project protocol

Auditory brainstem response in 7 inbred founder strains of the Collaborative Cross   (2020)

German Mouse Clinic and Department of Infection Genetics, HZI
With: Hrabě de Angelis M, Fuchs H, Gailus-Durner V, Becker L, Klopstock T, Lengger C, Kollmus H, Schughart K

See also: GMC17 animal documentation


German Mouse Clinic: Phenotyping Pipeline

Auditory brainstem response: 17-18 wks of age

 

  • Project protocol - Contents

    Workflow and sampling

    Step
    Procedure
    Equipment
    Data collected
    1 Body weight measured Balance Body weight
    2 Mice anesthetized - -
    3 Auditory brainstem response See below Auditory brainstem responses to click and various frequencies

    Equipment and supplies

    • Balance: Ohaus (AV213C)
    • Audio signal generators, amplifiers, loudspeakers
    • Calibration equipment (microphone etc)
    • Biological amplifier and headstage
    • Data acquisition hardware
    • Software to control signal presentation and data acquisition
    • Sound attenuating chamber
    • EEG needles
    • Heating blanket
    • Auditory brainstem response system: Tucker Davis Technologies (ABR RP2.1)
    • Software: Sanger Bespoke Averager

    Reagents and solutions

    • Ketamine
    • Xylazine

    Procedure: Auditory brainstem response (ABR)

      1. Mice are anesthetized and placed on heating blanket in the sound chamber.
      2. Sub-dermal needle electrodes are inserted (active electrode on vertex; reference electrode overlying left bulla; ground electrode overlying right bulla).
      3. Mouse is placed unrestrained in a prone position, nose forward, at the calibrated distance from the leading edge of the speaker to the mouse's interaural axis, on a thermostatically controlled blanket, inside a sound-attenuating booth.
      4. A click-evoked ABR (70 dB sound pressure level (SPL)) is recorded to ensure a good ABR is present (optional).
      5. ABRs are recorded to clicks (10 µs duration, positive transient) presented from 0-85 dB SPL in 5 dB steps, presented 256 times at 42.6/s.
      6. ABRs are recorded to the following frequencies at 0-85 dB SPL, if not otherwise indicated (stimulus extension used for some to 90 dB SPL (see download file)): 6kHz, 12kHz, 18 kHz, 24 kHz and 30 kHz, presented in 5 dB intervals. Tone pips are 5 ms in duration, with a 1 ms rise-fall time, presented 256 times at 42.6/s. Tone stimuli are presented in decreasing frequency order for a particular sound level and from low to high stimulus level.
      7. A final click-evoked ABR is recorded (70 dB SPL) to check for any deterioration of the click-evoked response during recordings (optional).
      8. Data are analyzed using Sanger Bespoke Averager software for ABR.
      9. For statistical analysis values above measurement limit (80 or 90 kHz) were set to 100.

    Data collected by investigator

    • Body weight
    • ABR to click stimulus
    • ABR to various frequencies