Sucrose Preference Test
Overview
The sucrose preference test (SPT) is the primary preclinical assay for anhedonia — the reduced capacity to experience pleasure that is a core symptom of major depressive disorder. In this two-bottle choice paradigm, animals are given simultaneous access to a bottle of sucrose solution (typically 1-2%) and a bottle of plain water over a 24-48 hour testing period. Healthy rodents exhibit a strong innate preference for sweet solutions (typically 80-95% sucrose preference), mediated by mesolimbic dopaminergic reward circuitry involving the ventral tegmental area, nucleus accumbens, and orbitofrontal cortex. The opioid system also contributes to hedonic processing of sweet taste via mu-opioid receptors in the nucleus accumbens shell.
Sucrose preference is calculated as: (sucrose intake / total fluid intake) x 100. A preference ratio below 65% is conventionally interpreted as anhedonia, though this threshold varies by strain and laboratory. Key dependent variables include sucrose preference percentage, absolute sucrose intake, total fluid consumption (to control for general consummatory changes), and within-session temporal drinking patterns. Bottle positions must be counterbalanced to control for side preference, and a habituation period with two water bottles precedes testing. The SPT is typically employed as a readout after chronic stress induction protocols rather than as a standalone acute test.
ConductMaze integrates with precision lickometer systems to provide real-time fluid consumption tracking with individual lick resolution. The software automatically calculates preference ratios, corrects for bottle leakage using control cage measurements, manages counterbalanced bottle positioning schedules, and generates longitudinal preference curves across multi-week stress and treatment protocols. Circadian drinking patterns are resolved to identify anhedonia-specific deficits versus general hypodipsia.
Trial Flow
Habituation Phase
Animals habituated to two-bottle setup with plain water in both bottles for 24-48 hours.
Baseline Preference
First sucrose vs water exposure to establish individual baseline preference ratios.
Bottle Counterbalance
Bottle positions swapped at midpoint to control for side preference bias.
Consumption Measurement
Bottles weighed (gravimetric) or lick counts recorded (lickometer) at defined intervals.
Preference Calculation
Sucrose preference ratio computed; threshold applied to classify anhedonia.
Leakage Correction
Control cage bottle weights used to correct for drip artifacts.
Longitudinal Tracking
Preference plotted across stress/treatment timeline.
Test End
Final preference calculated; data exported with body weight normalization.
Parameters
| Parameter | Type | Default | Description |
|---|---|---|---|
| Sucrose Concentration | float | 1.0 | Sucrose solution concentration as weight/volume percentage (standard: 1-2%) |
| Test Duration | duration | 24 h | Duration of each preference test period (12, 24, or 48 hours) |
| Habituation Period | duration | 48 h | Duration of two-bottle water habituation before first sucrose exposure |
| Counterbalance Interval | duration | 12 h | Time interval at which bottle positions are swapped |
| Anhedonia Threshold | float | 65.0 | Sucrose preference percentage below which an animal is classified as anhedonic |
| Measurement Method | enum | Gravimetric | Method for quantifying consumption (Gravimetric bottle weighing or Lickometer) |
| Measurement Interval | duration | 12 h | Frequency of bottle weight measurement or lick data download |
| Food Deprivation | enum | None | Whether animals are food-deprived before test (None, 12h, or 24h — increases sensitivity) |
| Control Cages | integer | 2 | Number of cages without animals used to measure bottle leakage |
Metrics
| Metric | Unit | Description |
|---|---|---|
| Sucrose Preference | % | Sucrose consumption as percentage of total fluid intake — primary anhedonia measure |
| Sucrose Intake | mL | Absolute volume of sucrose solution consumed (leakage-corrected) |
| Water Intake | mL | Absolute volume of plain water consumed (leakage-corrected) |
| Total Fluid Intake | mL | Combined sucrose plus water consumption — controls for general consummatory changes |
| Normalized Sucrose Intake | mL/g BW | Sucrose intake normalized to body weight for cross-animal comparison |
| Preference Delta | % | Change in sucrose preference from baseline — measures stress-induced anhedonia magnitude |
| Dark-Phase Preference | % | Sucrose preference during the dark (active) phase only — more sensitive in some paradigms |
Sample Data
| Animal | Group | Sucrose_mL | Water_mL | Total_mL | Preference_pct | Baseline_pct | Delta_pct |
|---|
Representative data for illustration purposes. Actual values will vary by species, strain, and experimental conditions.
Applications
- 1Anhedonia phenotyping — quantifying hedonic deficits after chronic unpredictable stress, social defeat, or corticosterone models
- 2Antidepressant efficacy — measuring restoration of sucrose preference as a translational endpoint for treatment response
- 3Reward circuit dissection — combining SPT with optogenetic manipulation of VTA-NAc dopaminergic projections
- 4Longitudinal monitoring — tracking weekly preference changes across multi-week stress induction and recovery protocols
- 5Strain susceptibility — identifying resilient versus susceptible phenotypes within genetically heterogeneous populations
Related Protocols
Compatible Products
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