A system for continuous and automated measurement of mouse home-cage drinking with automated control of liquid access

Abstract

Measurement of drinking behavior in laboratory animals is an often utilized method in many areas of scientific research, including the study of ingestive behaviors and addictions. We have designed a system that measures drinking by continuously tracking fluid-filled bottle weights with load cells and calculating change in fluid weight per drinking bout. The load cells serve both as a contact sensor that detects mouse-spout contact, as well as a monitor of fluid weight change per contact bout. The design described here fulfills several key criteria, including automated and continuous recording of drinking in the home-cage, automated control of liquid access, and inexpensive/reproducible fabrication. These features may allow researchers to generate high-resolution, detailed information on drinking behavior in high-throughput experimental designs. Here, we provide an overview of the design and present results from tests to validate the system. C57BL/6J mice were offered water and ethanol concurrently, using this system. Consumption weights were determined by the system and independently by conventional approaches. The results indicated a near-perfect correlation between the two methods, indicating the system returned valid consumption weights. This system functions as a valid drinking monitor that provides temporally precise data with a low cost design.

Gonadal Sex and Sex-Chromosome Complement Interact to Affect Ethanol Consumption in Adolescent Four Core Genotypes Mice

“…Liquid (LIQ) consumption was monitored via a 3-bottle apparatus attached to a modified standard home cage as described previously [90]. Bottles sit on a load cell that measures small changes in bottle weight, and contact by the animal, at a sampling rate of ~2.2 samples/second.…”

“…Bottles were constructed from modified 50 mL conical tubes fitted with a silicone stopper and curved sipper tube within which were two steel ball bearings to minimize non-contact liquid loss. As the temporally discrete recording of consumption includes a taring and re-taring of bottle weight, the contamination of non-contact liquid loss (e.g., “leak”) is minimized [90]. Test cages were placed within sound and light attenuating cubicles equipped with a fan for ventilation and white noise.…”

“…Behavior was recorded as a sequence of discriminable bouts of liquid consumption as described previously [90]. To filter out spout contacts that were not associated with drinking, bouts were delimited by pauses of >= 5 seconds (limit of temporal resolution) and those of amounts smaller than 5 mg were excluded as such values approximate a limit of detection (non-consummatory contacts are distributed around zero within a ±5 mg range).…”