Citric Acid Water as an Alternative to Water Restriction for High-Yield Mouse Behavior

Abstract

Powerful neural measurement and perturbation tools have positioned mice as an ideal model species for probing the neural circuit mechanisms of cognition. Crucial to this success is the ability to motivate animals to perform specific behaviors. One successful strategy is to schedule their water intake, rewarding them with water during a behavioral task. However, water scheduling requires rigorous monitoring of animal's health and hydration status, and can be challenging for some animals.Here, we present an alternative that allows mice more control over their water intake: free homecage access to water to which a small amount of Citric Acid (CA) has been added. CA makes water taste slightly sour, but still palatable. Mice reduce their intake of CA water while still maintaining a healthy weight. Home-cage access to CA water has only subtle impacts on their willingness to perform a decision-making task, in which they are rewarded with sweetened water. CA water is thus a promising alternative that allows animals more control over their water intake without interference to behavioral performance.

An operant temperature sensory assay provides a means to assess thermal discrimination

“…nutritive rewards) can result in different levels of motivation in task learning. 42,43 Therefore, it is possible that a different reward scheme might have helped motivate more mice, resulting in larger groups recruited for testing. With only approximately half of mice meeting our criterion for testing in this study, some of our results must be interpreted carefully to not assume our findings are representative of all mice.…”

Treadmill-based task for assessing spatial memory in head-fixed mice

“…In order to ensure mice are sufficiently motivated to walk on the treadmill for water rewards, water consumption must be restricted in some way that follows IACUC-approved water deprivation protocols. We replace homecage water with 2% citric acid water, which reduces water intake and is a safer alternative to removing homecage access to water completely ( Reinagel, 2018 ; Urai et al., 2021 ). Replace homecage water with 2% citric acid water.…”

Knowledge across networks: how to build a global neuroscience collaboration

“…This exchange enables a more comprehensive understanding of data generated in our laboratory spaces. Take, for example, a recent staff-postdoc collaboration that synthesized animal husbandry techniques and behavioral analysis: ad libitum access to 2% citric acid water works as well as traditional water restriction for task-performing mice [27].…”