Basal Ganglia/drug effects; Dopamine/metabolism; Fluoxetine/pharmacology; Selective Serotonin Reuptake Inhibitors/pharmacology; Serotonin Plasma Membrane Transport Proteins/metabolism; Signal Transduction/drug effects; 3,4-Dihydroxyphenylacetic Acid/metabolism; Age Factors; Animals; Animals, Newborn; Basal Ganglia/pathology; Basal Ganglia/physiopathology; Cell Count; Chromatography, High Pressure Liquid/methods; Dopamine Agents/pharmacology; Dopamine Agents/therapeutic use; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Interactions; Exploratory Behavior/drug effects; Fluoxetine/therapeutic use; Homovanillic Acid/metabolism; Levodopa/pharmacology; Levodopa/therapeutic use; Male; Mice; Mice, Transgenic; Movement Disorders/drug therapy; Movement Disorders/genetics; Movement Disorders/pathology; Psychomotor Performance/drug effects; Random Allocation; Rotarod Performance Test; Serotonin/metabolism; Serotonin Plasma Membrane Transport Proteins/deficiency; Selective Serotonin Reuptake Inhibitors/therapeutic use; Signal Transduction/physiology; Substantia Nigra/drug effects; Substantia Nigra/metabolism; Substantia Nigra/pathology; Ventral Tegmental Area/cytology; Ventral Tegmental Area/drug effects