Protocol for Rotarod Coordination testing

Apparatus

2 SmartRods from Accuscan. Each box has a plastic bedding tray added that is about 2 cm above the photocell beams so that the mouse can never break the photocell beams. The tray should be filled with about 1cm of the standard 1/4" bed-o-cob bedding. The plastic rod is covered with 320 grip emery paper (3M 413Q WetorDry paper A weight W2) using rubber cement.

The two plastic SmartRod boxes are placed on the same table 40 cm apart and with the front edge of the base set back 25cm from the front edge of the table (Point here is so that the impetus to jump and the confusions presented by extra- apparatus cues are equilibrated at the sites).

General Procedures

1. Mice are tested in squads of two. The cage containing the squad is moved from the rack to a table adjacent to the rotarod and the water bottle and top are removed.

2. The experimenter sits 4 feet back from the rotarod during each trial. Occasionally, a mouse will fall from the rotarod because it is attempting to climb up the flat face of the disk. If this happens, record a "fall" latency (distinguishable from the end-latency that will occur later when the mouse is finally thrown from the rod), immediately place the mouse back on the (still-rotating) disk.

3. If a mouse jumps, record a jump latency, and place it immediately back on the rotating rod. If it continues to jump, continue to record jump latencies, and replace the animal. Common sense will be used to determine when/if an uncooperative jumper will be eliminated from the experiment.

4. Clean bedding is placed in the tray at the start of a session and will not be changed until the end of a session.

Specific Procedures

1. The experimenter carries the cage to the rotarod, picks up a mouse by the tail and places it on the rotarod, facing away from the experimenter. Close the lid and turn on the rotarod, preset to a constantly accelerating rate of 80 RPM/minute. Begin timing. This should require less than 15 seconds. Repeat for the second mouse. If a mouse falls or jumps, it is placed back in its lane on the rotarod until all mice are in position. If any mice turn around to face the experimenter, this is ignored.

2. The experimenter sits four feet back from the rotorod during each trial.

3. Latency of each mouse to fall from the rotarod is recorded. As each mouse falls, it is left in the corncob bedding underneath the rod until both mice have fallen.

4. After both mice have fallen, the rotarod is turned off and any boli removed with a tissue. After an ITI of 30 seconds since the last mouse fell, the mice are given a second trial as described. Ten massed trials are given, and mice are then returned to their home cage, which is returned to the table, then both cages to the rack.