An Open Source Automated Two-Bottle Choice Test Apparatus for Rats

Area of Science:

• Neuroscience
• Behavioral Science
• Engineering

Background:

• Two-bottle choice tests are crucial for studying animal models of addiction, depression, and anhedonia.
• Existing methods for analyzing drinking microstructure can be costly and lack comprehensive data capture.

Purpose of the Study:

• To develop a user-friendly, affordable, 3D-printed apparatus for detailed analysis of rodent drinking behavior.
• To integrate hydrostatic depth sensors and beam break lick sensing for real-time volumetric and licking microstructure data.

Main Methods:

• A 3D-printed, Arduino-controlled apparatus was designed and built for two-bottle choice tests.
• The system incorporates hydrostatic depth sensors for volumetric measurements and beam break sensors for lick detection.
• The apparatus was validated using alcohol preference tests in rats.

Main Results:

• The apparatus provides accurate, real-time volumetric measurements (±0.086 ml) and licking microstructure data.
• The cost of building the apparatus is under $180 CAD, with reduced costs for additional units.
• The design demonstrated consistency in drinking bouts and volume consumed.

Conclusions:

• This novel apparatus offers an accurate, robust, and cost-effective solution for studying complex behaviors in rodent models.
• It enhances the traditional two-bottle choice paradigm by enabling detailed microstructure analysis of both licking and volume.
• The design facilitates advanced research in addiction, motivation, and reward evaluation without requiring expensive specialized equipment.