Cocaine-stimulated Locomotor Activity Testing Protocol

Background Discussion

This test should have the same length as the Monday activity test (15 min). Cocaine will be administered immediately prior to placement in the activity chamber.

Otherwise the protocol here is the same with regard to the general apparatus, room and procedure as the Monday protocol. Only components that vary from the Monday Protocol are listed.

Specific Protocol for Testing

1. Weigh all 32 mice for the am or pm session at once, at the outset of that session.

2. Mice are transported, in home cages (bottles off) in groups of two cages for the squad of four, into the testing room. Cages are placed adjacent to the test chambers and mice are injected. In Portland, the whole AM or PM squad was wheeled into the testing room directly (no holding area) with water bottles ON (Portland Bottles don't leak). Then weighed. After all done, put back on cart in testing room.

3. Syringes (27 gauge, half inch hypodermic needles on disposable 1cc tuberculin syringes) are filled prior to mice being transported to the activity apparatus. Mice are injected with 20 mg/kg of cocaine in saline. The injection volume is 10 ml/kg (.1 cc per 10 g body weight). Thus the cocaine is made up in saline in a 20 mg/10 ml concentration. Intraperitoneal injections are to be employed.

4. Mice are immediately placed into the test chamber following injection - without being placed down. Shifting to right hand for placement can be accomplished after setting the syringe down. I assume holding with left hand for injection with syringe in right hand.

5. Mice are put into the plexiglas chambers in the activity monitors, with the mouse placed in the center facing away from the experimenter. Lids are placed on, and the sound attenuation chambers are closed. Since the control programs permit starting each box individually, this sequence should be done for each mouse individually. That is, placement into the chamber, closing the sound attenuation chamber, and starting the session for each mouse prior to placement of the next mouse. This way varying amounts of time in box prior to session are avoided, although some variation in elapsed time from home cage occurs.

6. Tests are 15 min tests, set up with three five min blocks.

7. At the completion of each mouse's test, the mouse is removed and replaced in the home cage. The control for the box is switched at the same time. As each mouse's session completes, the mouse can be removed. After all four, the control program is tended so that the files are saved, and the next squad set up.

8. All monitors are then cleaned.

9. Mice are transported back to the holding room (bottles now back on).