TailTimer: A device for automating data collection in the rodent tail immersion assay

Area of Science:

• Neuroscience
• Animal Behavior
• Pain Research

Background:

• The tail immersion assay is a common method for assessing acute thermal pain in animals.
• Manual timing and lack of precise temperature recording limit the reproducibility of this assay.
• Discrepancies in literature may stem from these limitations in current methods.

Purpose of the Study:

• To develop an automated device, TailTimer, for precise and reproducible measurement of tail withdrawal latency and water temperature.
• To enhance the usability and data integrity of the tail immersion assay.

Main Methods:

• Designed TailTimer using a Raspberry Pi, digital temperature sensor, and RFID system for automated data recording and animal identification.
• Implemented software to ensure water temperature stability (± 0.25°C) and allow RFID-based user commands.
• Utilized the device to investigate thermal pain thresholds, drug effects, and strain differences.

Main Results:

• Demonstrated a negative linear relationship between tail withdrawal latency and water temperature (47-50°C).
• Identified a significant effect of water mixing speed on latency, a previously unreported factor.
• Observed significant differences in latency following oxycodone administration and between different animal strains.

Conclusions:

• TailTimer significantly enhances the reproducibility and reliability of the tail immersion assay for thermal pain measurement.
• The device's sensitivity is validated by its ability to detect drug effects, environmental factors, and genetic variations.
• TailTimer offers a valuable tool for advancing pain research in animal models.