title: Are serotonin transporter knockout mice 'depressed'?: hypoactivity but no anhedonia.
abstract: Although the serotonin transporter is a key target for antidepressants, its exact role in depression etiology remains unclear. While serotonin transporter knockout mice are a potential model to examine this problem, their depression profile is unclear in several 'despair' tests, and may be confounded by their hypoactivity phenotype (confirmed here by marble-burying and bedding tests). To assess depression in these mice, we evaluated wild-type, heterozygous, and serotonin transporter knockout C57BL/6 male mice on a well-validated, anhedonia-based depression paradigm, the sucrose preference test. Overall, all three genotypes showed similar sucrose preference, indicating an unaltered hedonic state. These results demonstrate that depression-like behavior (unlike hypoactivity) is not a baseline phenotypic feature of serotonin transporter knockout mice, suggesting anew that these mice do not represent a genetic model of depression.
authors.affiliation: Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, Maryland 20892-1264, USA. kalueva@mail.nih.gov
authors.forename: Allan V
authors.initials: AV
authors.lastname: Kalueff
authors.forename: Pamela S
authors.initials: PS
authors.lastname: Gallagher
authors.forename: Dennis L
authors.initials: DL
authors.lastname: Murphy
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D003863:Depression / Q000235:genetics* / Q000503:physiopathology*; D005106:Exploratory Behavior / Q000502:physiology; D005518:Food Preferences / Q000502:physiology*; D018476:Hypokinesia / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D051379:Mice; D018345:Mice, Knockout / Q000502:physiology*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000172:deficiency*; D013395:Sucrose / Q000008:administration & dosage
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins; D013395:Sucrose