Genotype- and experience-dependent susceptibility to depressive-like responses in the forced-swimming test.
BACKGROUND
The forced-swimming test (FST) is utilized to reproduce passive coping responses to stress that may model a relevant aspect of human depression in rodent species. Animals showing high levels of passive responses to the FST are assumed to model pathologically depressed individuals.


OBJECTIVE
We evaluated sensitivity of FST-induced behavioral responses to the interaction between genetic and environmental influences.


METHODS
Behavioral responses to FST were evaluated in naive mice of the C57BL/6 and DBA/2 strains, in mice of both strains pre-exposed to FST 14 days before test, and in FST-experienced animals subsequently exposed to 12 days of stress experience (food restriction).


RESULTS
C57BL/6 mice are characterized by high propensity to adopt passive coping responses in the FST. Moreover, stress enhances FST-induced immobility in mice of the C57BL/6 strain but reduces this response in DBA/2 mice. Finally, FST-induced immobility in C57BL/6 mice is reduced by chronic treatment with clinically effective antidepressants.


CONCLUSIONS
These results support the view that behavioral and neural responses to FST exhibited by C57BL/6 mice can be usefully exploited by pre-clinical research on depression.
Alcaro
Antonio
A
Department of Psychology, University "La Sapienza", via dei Marsi 78, 00185 Rome, Italy.
Cabib
Simona
S
Ventura
Rossella
R
Puglisi-Allegra
Stefano
S
D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000661:Amphetamine / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology; D003863:Depression / Q000235:genetics / Q000523:psychology*; D003891:Desipramine / Q000494:pharmacology; D020022:Genetic Predisposition to Disease; D005838:Genotype; D007103:Immobilization / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D011897:Random Allocation; D012931:Social Environment; D013045:Species Specificity; D013312:Stress, Physiological / Q000235:genetics / Q000523:psychology*; D013550:Swimming / Q000502:physiology / Q000523:psychology*; D013997:Time Factors
D018759:Adrenergic Uptake Inhibitors; D000929:Antidepressive Agents, Tricyclic; D000661:Amphetamine; D003891:Desipramine