Isolation-induced behavioural changes in a genetic animal model of depression

• Published in: Behavioural brain research Vol. 230; no. 1; pp. 85 - 91
• Main Authors: Fischer, Christina W., Liebenberg, Nico, Elfving, Betina, Lund, Sten, Wegener, Gregers
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 21.04.2012
• Subjects: Analysis of Variance; Animal behaviour; Animals; Behavior, Animal - physiology; Blood Glucose - metabolism; Body Weight - genetics; Brain-Derived Neurotrophic Factor - genetics; Brain-Derived Neurotrophic Factor - metabolism; CREB-Binding Protein - genetics; CREB-Binding Protein - metabolism; Depression; Depression - genetics; Depression - metabolism; Depression - physiopathology; Disease Models, Animal; Eating - genetics; Exploratory Behavior; Freezing Reaction, Cataleptic - physiology; Gene Expression Regulation - genetics; Glucose Tolerance Test; Insulin - blood; Male; Maze Learning - physiology; Metabolism; Rats; Recognition (Psychology) - physiology; RNA, Messenger - metabolism; Social isolation; Social Isolation - psychology; Stress; Swimming - physiology; Swimming - psychology; Time Factors; Vascular Endothelial Growth Factor A - genetics; Vascular Endothelial Growth Factor A - metabolism; Vascular Endothelial Growth Factor Receptor-2 - genetics; Vascular Endothelial Growth Factor Receptor-2 - metabolism; Depression; Animal behaviour; Metabolism; Social isolation; Stress
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2012.01.050

► The impact of social isolation in a genetic rat model of depression was investigated. ► Isolation suppresses the depression-like behaviour in the investigated rat model of depression. ► Healthy subjects are at least as responsive to isolation as the depressive phenotype. Depression is a heterogeneous disorder displaying a range of symptoms including feelings of despair and social withdrawal. Social isolation may complicate the progression of depression and have effects on both behaviour and physiology. The aim of this study was to investigate the effects of social isolation on behavioural and metabolic parameters in a genetic rat model of depression, the Flinders Sensitive and Resistant Line (FSL/FRL) rats. Rats were housed either individually (social isolation) or pair-housed for 5weeks, and subjected to behavioural testing and metabolic evaluation. We found that social isolation erased the characteristic difference in depressive-like behaviour, measured as immobility in the forced swim test, between the FSL and FRL rats. Social isolation affected both strains equally in impairing object recognition memory, while leading to an increased explorative behaviour in the elevated plus maze test. Surprisingly, single-housed FRL rats showed an increased food intake compared to pair-housed FRL rats, whereas no difference in food intake or body weight was evident in FSL rats. Our results indicate that social isolation for 5weeks causes behavioural alterations, independent of strain. As the changes in appetite were only observed in the FRL rats, this may suggest that this strain responds to the stress of isolation by a change in feeding behaviour.