title: Antidepressant-like effects in various mice strains in the forced swimming test.
abstract: BACKGROUND
  Strain differences in mice have been reported in response to drugs in the mouse forced swimming test (FST), even if few antidepressants were examined.
  
  
  OBJECTIVE
  The aim of the present study was to investigate the influence of genetic factors, using five antidepressants (imipramine, desipramine, citalopram, paroxetine and bupropion) in the mouse FST, in outbred strains (Swiss, NMRI) and inbred strains (DBA/2, C57BL/6J Rj). Moreover, whole brain levels of dopamine (DA), noradrenaline (NA), serotonin (5-HT) in vehicle treated animals, which were or were not subjected to the FST, were measured by HPLC analysis in an attempt to explain behavioural differences.
  
  
  METHODS
  For each antidepressant, a dose range (1-16 mg/kg) was tested in the locomotor apparatus and only non-psychostimulant doses were then tested in the FST in order to detect antidepressant-like activity.
  
  
  RESULTS
  No baseline differences among Swiss, NMRI, DBA/2 and C57BL/6J Rj strains were observed in our experiments, allowing the comparison of different antidepressants in each strain. Imipramine (16 mg/kg), desipramine, citalopram (4-16 mg/kg) and paroxetine (8 and 16 mg/kg) treatment decreased the immobility time in the Swiss strain and the size of the effect reached more than 20% for each of these antidepressants. C57BL/6J Rj was the only strain sensitive to bupropion (2 and 4 mg/kg). In the NMRI strain, only paroxetine treatment decreased the immobility time (16 mg/kg).
  
  
  CONCLUSIONS
  Our study showed that drug sensitivity is genotype dependent. FST results have shown that Swiss mice are the most sensitive strain to detect 5-HT and/or NA treatment. The use of DBA/2 inbred mice may be limited, as an absence of antidepressant-like response was observed in the FST. The lack of sensitivity to antidepressant treatment in DBA/2 strains could be due to high DA, NA and 5-HT whole brain concentrations.
authors.affiliation: EA 3256 Neurobiologie de l'anxiété et de la dépression, Faculté de Médecine, 1 rue Gaston Veil, BP 53508, 44035, Nantes Cedex 01, France.
authors.forename: Denis Joseph Paul
authors.initials: DJ
authors.lastname: David
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Renard
authors.forename: Pascale
authors.initials: P
authors.lastname: Jolliet
authors.forename: Martine
authors.initials: M
authors.lastname: Hascoët
authors.forename: Michel
authors.initials: M
authors.lastname: Bourin
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000378:metabolism* / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D001923:Brain Chemistry / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D008124:Locomotion / Q000187:drug effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D018377:Neurotransmitter Agents / Q000378:metabolism; D013045:Species Specificity; D013550:Swimming
chemical_list: D000928:Antidepressive Agents; D018377:Neurotransmitter Agents