Lack of dopamine D1 receptors in the antidepressant actions of (R)-ketamine in a chronic social defeat stress model.

It is reported that dopamine D1 receptors in the medial prefrontal cortex play a role in the antidepressant actions of (R,S)-ketamine. However, its role in the antidepressant actions of (R)-ketamine, which is more potent than (S)-ketamine, is unknown. In the locomotion test, tail suspension test, forced swimming test and 1% sucrose preference test, pretreatment with dopamine D1 receptor antagonist SCH-23390 did not block the antidepressant effects of (R)-ketamine in the susceptible mice after chronic social defeat stress. These findings suggest that dopamine D1 receptors may not play a major role in the antidepressant actions of (R)-ketamine.