Behavioral models in mice. Implication of the alpha noradrenergic system.

1. The mechanism of action of drugs might change according to the test used. Several noradrenergic drugs were tested in order to understand their implication in the mobility tests. 2. It was found that clonidine, an Alpha 2 agonist, acted differently according to the test used. It provoked sedation in spontaneous activity test, and anti-immobility effects in the other tests. 3. Tail suspension test is able to show the double acting of clonidine. 4. Idazoxan might act either as an alpha 2 antagonist or as partial alpha 2 agonist. TST shown the unexpected partial alpha agonist effect of the molecule. 5. Forced swimming test is more specific for predicting antidepressant activity than tail suspension test which is close to a spontaneous activity model.