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Purpose
To investigate mechanical sensitivity in wild type and genetically altered mice.
Experimental Design
Minimum number of mutant animals: 7 males + 7 females
Age at test: 17 weeks
Sexual dimorphism:
Procedure
- Baseline measurement
- Set up the testing room and equipment. Check the condition of the von Frey filaments.
- Place mice into the testing arenas and leave them to habituate for the specified length of time.
- Once habituated, test the mouse with the starting filament. When the mouse has all four feet on the platform, position the starting filament below the mid-plantar surface of the foot.
- Press the filament against the foot until the filament bends. Hold the filament in position for 3 seconds, or until the mouse moves its foot.
- Mark the response as '0' if the mouse does not react, or 'X' if it does react to the filament.
- Move on to testing the next mouse with the starting filament.
- Once all mice have been tested with the starting filament, test them with the next filament.
- If the mice did respond to the previous filament, they should be tested with the filament of the next smallest size. Once tested, record the response.
- If the mice did not respond to the previous filament, they should be tested with the filament of the next largest size. Once tested, record the response.
- Continue testing the mice using the up-down pattern until the stated number of trials have been completed.
- Challenge
- The challenge should be administered 24 hours after the baseline measurement took place.
- Prepare the challenge injection.
- Anaesthetise the mouse.
- Administer the challenge to the plantar surface of the right hind paw.
- Monitor the condition of the mouse as it recovers from the anaesthetic.
- Test 1
- 24 hours after the challenge injection, re-test the mouse with the von Frey filaments using the same procedure as described for the baseline measurement.
- Test 2
- 48 hours after the challenge injection, re-test the mouse with the von Frey filaments using the same procedure as described for the baseline measurement.
Notes
This procedure is a pilot study from the Pain Phenotyping Pilot