Computational modeling reveals latent components of mouse behavior in the sucrose preference test

The sucrose preference test (SPT) measures the relative preference of a sucrose solution over water to assess hedonic behaviors in rodents. The SPT involves numerous complex behaviors, including learning, motivation, and choice. Yet, it remains uncertain whether its main outcome measure, sucrose preference, can reflect these behavioral subcomponents. Here, we conducted an experimental and computational decomposition of mouse behavior in the SPT and discovered previously unrecognized behavioral subcomponents associated with changes in sucrose preference. While both acute and chronic stress reduced sucrose preference, only chronic stress evoked anhedonia. Additionally, reduced sucrose preference induced by optogenetics is not always indicative of anhedonia but can also reflect learning deficits. Even small variations in experimental conditions influence behavior, task outcome and interpretation. Thus, an ostensibly simple behavioral task can entail high levels of complexity, demonstrating the need for careful dissection of behavior into its subcomponents when studying the underlying neurobiology.