TMU4142 is a selective 5-HT1a agonist with high GoA activity. Its Gi3 activity is relatively weak, allowing it to swiftly produce antidepressant-like effects or inhibit serotonergic neuron firing without significantly activating 5-HT1a autoreceptors in the DRN region. In mouse models of depression, TMU4142 demonstrates rapid-onset antidepressant effects. TMU4142 is applicable for antidepressant research.