Aberrant responses in social interaction of dopamine transporter knockout mice.
The dopamine (DA) transporter (DAT) controls the temporal and spatial resolution of dopaminergic neurotransmission. Disruption of the Dat1 gene in mice leads to increased extracellular DA concentrations and reduced expression of D1- and D2-like receptors in striatum. The mutants are hyperactive in the open field and they display deficits in learning and memory. In humans, dopaminergic dysfunction has been associated with a number of different psychiatric disorders and some of these conditions are accompanied by abnormal social responses. To determine whether social responses were also impaired in DAT knockout (KO) mice, behaviors of group- and isolation-housed animals were compared. All group-housed animals readily established hierarchies. However, the social organizations of the mutants were changed over time. Under both group- and isolation-housed conditions, mutants exhibited increased rates of reactivity and aggression following mild social contact. In isolation, exposure to a novel environment exacerbated these abnormal responses. Regardless of housing context, stereotyped and perseverative patterns of social responses were a common feature of the KO repertoire. In fact, many abnormal behaviors were due to the emergence and predominance of these inflexible behaviors. These data suggest that KO mice may serve as a useful animal model for understanding not only how DA dysfunction contributes to social abnormalities, but also how behavioral inflexibility distorts their social responses.
Rodriguiz
Ramona M
RM
Department of Psychiatry, Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, NC 27710, USA.
Chu
Richard
R
Caron
Marc G
MG
Wetsel
William C
WC
D000374:Aggression / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D004192:Discrimination, Psychological / Q000502:physiology; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D005838:Genotype; D006608:Hierarchy, Social; D007398:Interpersonal Relations; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout / Q000235:genetics / Q000523:psychology*; D009419:Nerve Tissue Proteins; D012044:Regression Analysis; D012903:Smell / Q000502:physiology; D012931:Social Environment; D013239:Stereotyped Behavior; D013315:Stress, Psychological; D013997:Time Factors
D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493215:Slc6a3 protein, mouse