Assess inhibitory avoidance memory through step-down latency.
Metrics automatically extracted by ConductVision.
Time on platform during retention — primary memory readout
Naive step-down time before shock exposure
Test-to-training latency ratio reflecting memory strength
Total descents during retention — fewer indicates better memory
Cumulative duration in the safe elevated zone
Immobility on the platform indicating fear memory
The Step-Down Avoidance Test assesses single-trial inhibitory learning by placing a rodent on an elevated platform above a shock grid floor. During training, the animal receives a mild foot shock upon stepping down; during retention testing, the latency to step down serves as a readout of aversive memory consolidation.
ConductVision automates precise measurement of step-down latency and freezing duration, eliminating observer bias. This paradigm is a cornerstone of memory pharmacology research for evaluating cholinergic, GABAergic, and glutamatergic modulation of memory.
Standard Step-Down Avoidance configuration tracked by ConductVision.
| Parameter | Description | Default |
|---|---|---|
| Platform Size | Elevated safe zone dimensions | 7 × 25 cm (mouse) / 10 × 30 cm (rat) |
| Platform Height | Elevation above grid floor | 3 cm (mouse) / 5 cm (rat) |
| Grid Floor Area | Shock grid floor dimensions | 25 × 25 cm (mouse) / 30 × 30 cm (rat) |
| Shock Intensity | Foot shock current | 0.3–0.5 mA (mouse) / 0.5–0.8 mA (rat) |
| Shock Duration | Duration of shock upon step-down | 1–2 s |
| Training Protocol | Single-trial training with shock upon step-down | 1 trial |
| Test Latency (Short-term) | Retention test delay after training | 1.5–3 h |
| Test Latency (Long-term) | Long-term memory retention test | 24 h |
| Max Test Duration | Ceiling latency for retention test | 300 s |
| Step-Down Criterion | Definition of step-down event | All four paws on grid floor |
| Light Intensity | Overhead illumination | 200–300 lux |
| Habituation | Room acclimation | 30 min |
What parameter changes indicate in memory pharmacology and disease models.
Decreased Test Latency
Memory impairment — shorter step-down latency indicates failed aversive memory consolidation, seen with scopolamine (1 mg/kg) and protein synthesis inhibitors.
Increased Test Latency
Enhanced memory — longer avoidance latency after cognitive enhancers (donepezil, piracetam) or consolidation-enhancing treatments.
Reduced Retention Score
Weak memory consolidation — low test-to-training latency ratio indicates failure to form the shock-context association.
Increased Freezing on Platform
Strong fear memory — prolonged immobility on the platform reflects robust aversive memory, but excessive freezing may indicate generalized anxiety.
Multiple Step-Downs
Extinction within test session — repeated descents despite prior shock indicate accelerated extinction or impaired memory retrieval.
Impaired Memory Index
Normalized deficit — (Test - Train)/(Test + Train) ratio near zero indicates no memory-related latency increase.
Louise Corscadden PhD
Director
ConductVision supports automated tracking across dozens of behavioral tests.
