Update in the methodology of the chronic stress paradigm: internal control matters

Table 6 Factors of potential confounds in a free drinking two-bottle sucrose test

Own behavioral data	Source of confounds	Preventing of confounds in testing	References
Sucrose solution intake is affected by a position of the bottle on preferable or non-preferable side. Weeks of housing with two bottles does not abolish side preference in drinking behaviour	Side preference in drinking	Switching of the bottles in a middle of the test	[21, 22, 24, 38, 47, 92]
Individual patterns of absolute water intake in a 10-h test	Large individual variability in daily drinking patterns	Prolonged testing	[38, 47, 89, 92]
High variability in sucrose intake versus water intake in sucrose-naïve mice	Neophobia	Habituation to a sucrose solution Sucrose preference as a measure of hedonic sensitivity	[22, 38, 44, 47, 85, 90–92]
Ceiling values of sucrose preference after massive experience in sucrose ingestion	Sensitization to a sucrose taste	Use of sucrose solution of low concentrations	[24, 38, 47, 87, 88, 93]
High inter-individual variability in absolute intake of liquids	Inter-individual differences in metabolic needs	Use of a sucrose preference not sucrose intake as a measure of hedonic sensitivity	[25, 38, 44, 47, 85, 87, 92, 93]

Studies revealed major sources of confounding factors in the commonly used mouse sucrose preference test. The application of testing conditions which minimize their impact were shown to be benefitial in recently published literature.

ISSN: 1744-9081