Institut Pasteur, Centre National de la Recherche Scientifique (CNRS), URA 2182, Paris, France. pmlledo@pasteur.fr
In this issue of Neuron, Hen and colleagues shed new light on the behavioral effects of fluoxetine, one of the most commonly prescribed antidepressants. This report prompts us to revisit our understanding of the neural circuitry mediating mood disorders and also provides a framework for developing new antidepressant treatments.