University of Rouen

About: University of Rouen is a education organization based out in Rouen, France. It is known for research contribution in the topics: Population & Receptor. The organization has 7299 authors who have published 13209 publications receiving 313477 citations.

Individual differences in response to imipramine in the mouse tail suspension test

Abstract: The tail suspension test is a behavioural primary screen for detecting potential antidepressant drugs. In this test, a reduction of duration of immobility after treatment with imipramine is obtained in mice of the NMRI strain but not of the CD1 strain. The present experiments evidence important differences between individuals of the latter strain in both the amount of immobility observed in naive mice and the effects of three antidepressants. The reproducibility of the tail suspension-induced behavioural despair was high in individual CD1 male mice and allowed a preselection of spontaneous high and low immobility scorers. Only the high immobility scorers were responsive to imipramine (30 mg/kg), desipramine (30 mg/kg) and paroxetine (10 mg/kg). The percentage of spontaneous high immobility scorers was higher in NMRI (50%) than in CD1 (20%) mice, justifying the use of the former strain for screening potential antidepressants. However, controlling for individual differences in the spontaneous performance in this animal model of depression may provide a useful tool to study behavioural, neurochemical and neuroendocrine correlates of antidepressant action.

ARAD proteins associated with pectic Arabinan biosynthesis form complexes when transiently overexpressed in planta

Abstract: Glycosyltransferase complexes are known to be involved in plant cell wall biosynthesis, as for example in cellulose. It is not known to what extent such complexes are involved in biosynthesis of pectin as well. To address this question, work was initiated on ARAD1 (ARABINAN DEFICIENT 1) and its close homolog ARAD2 of glycosyltransferase family GT47. Using bimolecular fluorescence complementation, Forster resonance energy transfer and non-reducing gel electrophoresis, we show that ARAD1 and ARAD2 are localized in the same Golgi compartment and form homo-and heterodimeric intermolecular dimers when expressed transiently in Nicotiana benthamiana. Biochemical analysis of arad2 cell wall or fractions hereof showed no difference in the monosaccharide composition, when compared with wild type. The double mutant arad1 arad2 had an arad1 cell wall phenotype and overexpression of ARAD2 did not complement the arad1 phenotype, indicating that ARAD1 and ARAD2 are not redundant enzymes. To investigate the cell wall structure of the mutants in detail, immunohistochemical analyses were carried out on arad1, arad2 and arad1 arad2 using the arabinan-specific monoclonal antibody LM13. In roots, the labeling pattern of arad2 was distinct from both that of wild type, arad1 and arad1 arad2. Likewise, in epidermal cell walls of inflorescence stems, LM13 binding differed between arad2 and WILD TYPE, arad1 or arad1 arad2. Altogether, these data show that ARAD2 is associated with arabinan biosynthesis, not redundant with ARAD1, and that the two glycosyltransferases may function in complexes held together by disulfide bridges.