German Mouse Clinic: Phenotyping Pipeline
Auditory brainstem response: 17-18 wks of age
||Body weight measured
||Auditory brainstem response
||Auditory brainstem responses to click and various frequencies
- 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
Procedure: Auditory brainstem response (ABR)
- Mice are anesthetized and placed on heating blanket in the sound chamber.
- Sub-dermal needle electrodes are inserted (active electrode on vertex; reference electrode overlying left bulla; ground electrode overlying right bulla).
- 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.
- A click-evoked ABR (70 dB sound pressure level (SPL)) is recorded to ensure a good ABR is present (optional).
- 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.
- 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.
- A final click-evoked ABR is recorded (70 dB SPL) to check for any deterioration of the click-evoked response during recordings (optional).
- Data are analyzed using Sanger Bespoke Averager software for ABR.
- For statistical analysis values above measurement limit (80 or 90 kHz) were set to 100.
- ABR to click stimulus
- ABR to various frequencies