Cylinder test
The cylinder test (Schallert et al., 2000) measures forelimb use asymmetry. A mouse placed in a transparent cylinder rears and touches the wall with its forepaws. After a unilateral lesion (stroke, 6-OHDA, cortical injury), the paw contralateral to the lesion is used less.
Recording and calibration
Bottom view through the clear floor works best; a side view also works. Mark the rim circle (bottom view) or the floor line (side view) in Calibration. Without calibration no contacts can be found, and the result asks you to calibrate.
How a wall contact is detected
A forepaw is on the wall in a frame when both of these hold:
- it is still: speed below the still paw speed (0.8 BL/s);
- it is at the wall:
- bottom view: within the wall zone of the rim (outer 15 % of the radius);
- side view: raised above the floor line by at least the paw height (0.30 BL).
Dropouts of one or two frames are bridged. A run of such frames lasting at least the minimum contact (0.10 s) is one placement.
From placements to scores
- Rears: placements less than the rear gap (0.5 s) apart belong to the same rear.
- First contact per rear (default, Schallert et al., 2000): in each rear, the first paw placed is scored left or right. If the other paw follows within the simultaneous window (0.2 s), the rear is scored both.
- Every contact: each placement is scored. Left and right placements starting within the simultaneous window are merged into both.
- Limits: you can score only the first N seconds or the first N contacts (some protocols use the first 20 contacts or 3–5 minutes).
Checking and correcting
Open Review. Each contact is listed with its time. Tap to play it, and change its label to Left, Right, Both or Ignore if the automatic call is wrong. Edits are stored by frame, kept when parameters change, counted in Manually edited events, and exported in …_contacts.csv (auto and final label).
Measures
| Measure | Definition |
|---|---|
| Wall contacts scored | Left + right + both (after edits and limits) |
| Left / right / both paws | Counts |
| Left / right / both (% of all) | Count ÷ total × 100 |
| Contralateral use | contra ÷ (ipsi + contra) × 100 (Magno et al., 2019) |
| Contralateral incl. ½ both | (contra + ½ both) ÷ total × 100 |
| Asymmetry index | (ipsi − contra) ÷ (ipsi + contra + both) × 100 |
| Ipsilateral / contralateral | Counts relative to the lesioned hemisphere |
| Left use, L/(L+R) · Left − right bias | Shown when no lesion side is set |
| Rears with wall contact | Number of rears |
| Paw on wall (s), mean placement (s) | Per paw |
| Time to 20 contacts | Onset time of the 20th scored contact |
| Forepaw visibility | Detection rate of the less visible forepaw (% of frames) |
Set the lesioned hemisphere in Parameters to get the lesion-relative measures. A left-hemisphere lesion makes the right paw contralateral.
Parameters
| Parameter | Default | Effect |
|---|---|---|
| Camera | Bottom view | Bottom (rim circle) or side (floor line) |
| Lesioned hemisphere | Not set | Enables ipsi/contra measures |
| Scoring | First contact per rear | Or every contact |
| Swap left/right labels | Off | Use when the model's L/R refers to image sides (mirrored view) |
| Wall zone | 0.15 × r | Bottom view |
| Paw height | 0.30 BL | Side view |
| Still paw speed | 0.8 BL/s | Raise if contacts are missed; lower if passing paws are counted |
| Minimum contact | 0.10 s | Shortest placement |
| Simultaneous window | 0.20 s | Left + right within this = both |
| Rear gap | 0.5 s | Placements closer than this form one rear |
| Score first / contact limit | none | Time or count limit |