Reduce false activity from posture micro-tremors
Balance micro-tremors during hanging are often miscounted as activity. AI immobility detection improves accuracy versus manual re-scoring.
TSTDepression-like5 min read
Tail Suspension Test
Tail Suspension Test (TST): Principles & Protocol
Overview
The Tail Suspension Test (TST) suspends rodents upside-down by the tail in an inescapable setting. The transition from struggling to immobility—and immobility proportion—indexes behavioral despair.
Often complementary to FST, TST is used for rapid antidepressant screening, genetic depression models, psychiatric phenotypes, and depression-related transmitter systems.
Methods
- 1Fix the tail so the animal hangs head-down without footholds. Animals initially struggle then may enter despair-like immobility. Score immobility over 6 minutes as the depression-like readout.
Software capabilities
Deep quantification of despair metrics
Precisely log first-immobility latency and total immobility across the session for antidepressant and mechanism studies.
Flexible analysis windows without frame-by-frame clipping
Define custom intervals to extract immobility in targeted periods—faster and more reproducible than manual segmentation.
Analysis parameters
Advanced parameters
| Parameter | Description | Meaning | Unit |
|---|---|---|---|
| immobility_total_time | Total immobility time | Immobility: animal stops struggling and remains largely still while suspended | s |
| immobility_Ns_time | Immobility in a selected window | Extract immobility within N minutes after computing totals (e.g., last 4 or first 5) | s |
| immobility_time_ratio | Immobility time ratio | Total immobility / total time | % |
| first_immobility_time | Latency to first immobility | Time from start until first immobility bout | s |