Mainen, ZacharyCorreia, Patrícia2017-04-172017-04-172015-11-272015-10http://hdl.handle.net/10362/20495Serotonin (5-hydroxytryptamine, 5-HT) is a major neuromodulator linked to a disparate set of brain functions and disorders including depression and anxiety, but its fundamental roles in behavior remain a mystery. Three main theories for 5-HT function attempt to unravel how this complex neuromodulator acts in the brain: 1) behavioral inhibition, 2) sensorimotor hypothesis and 3) reward action. The vast literature in the 5-HT field is hard to reconcile and presents ambiguous results, due in part to the limitations of traditional pharmacological and physiological methods.(...)engdoctoral thesis