In contrast, heterotrimeric G-protein pathways, previously associated with low reactivity mental states like those involved in major depression, or the GAD2 gene, which plays a pivotal role in the control systems deployed by the PFC to repress agonistic reactions, are both down-regulated, guaranteeing the development of the adequate combative responses needed during a “corrida” event. The gene discussed is GAD2; the disease is major depressive disorder.