Serotonin keeps Mice Straight

Serotonin is a neurotransmitter commonly found in the central nervous system of humans and animals. Serotonin serves to control mood, appetite, and even sleep. In a study, conducted by Zhou-Feng Chen of Washington University School of Medicine in St. Louis, Chen genetically engineered male mice to lack serotonin producing brain cells. Chen observed the mating patterns of these mice and saw that they still went after female mice, like the control mice with serotonin producing brain cells. But when they were put with both a female mouse and a male mouse, 50 percent of these mice went after another male mouse, while the other 50 percent went after a female mouse. These serotonin male mice were also more likely, than the control mice, and try to serenade another male mouse, by giving off an ultrasonic squeak.
There is still a lot not known about this study. For example it is still not know how female mice would be effected if they were to lack serotonin. Also not known is how this would effect human beings. But if serotonin is a neurotransmitter, which effects human emotions, and is said to make people feel better, could taking away serotonin producing brain cells make someone almost, for lack of a better term, crazy?
http://www.sciencenews.org/view/generic/id/71586/title/Brain_chemical_influences_sexual_preference_in_mice