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Reduced anxiety and depression-like behaviours in the circadian period mutant mouse afterhours.

Keers R, Pedroso I, Breen G, Aitchison KJ, Nolan PM, Cichon S, Nöthen MM, Rietschel M, Schalkwyk LC, Fernandes C - PLoS ONE (2012)

Bottom Line: Variation in genes encoding components of the molecular circadian clock has been associated with increased risk of the disorder in clinical populations.Similarly in animal models, disruption of the circadian clock can result in altered mood and anxiety which resemble features of human mania; including hyperactivity, reduced anxiety and reduced depression-like behaviour.One such mutant, after hours (Afh), an ENU-derived mutant with a mutation in a recently identified circadian clock gene Fbxl3, results in a disturbed (long) circadian rhythm of approximately 27 hours.

View Article: PubMed Central - PubMed

Affiliation: MRC SGDP Centre, Institute of Psychiatry, King's College London, London, United Kingdom.

ABSTRACT

Background: Disruption of the circadian rhythm is a key feature of bipolar disorder. Variation in genes encoding components of the molecular circadian clock has been associated with increased risk of the disorder in clinical populations. Similarly in animal models, disruption of the circadian clock can result in altered mood and anxiety which resemble features of human mania; including hyperactivity, reduced anxiety and reduced depression-like behaviour. One such mutant, after hours (Afh), an ENU-derived mutant with a mutation in a recently identified circadian clock gene Fbxl3, results in a disturbed (long) circadian rhythm of approximately 27 hours.

Methodology: Anxiety, exploratory and depression-like behaviours were evaluated in Afh mice using the open-field, elevated plus maze, light-dark box, holeboard and forced swim test. To further validate findings for human mania, polymorphisms in the human homologue of FBXL3, genotyped by three genome wide case control studies, were tested for association with bipolar disorder.

Principal findings: Afh mice showed reduced anxiety- and depression-like behaviour in all of the behavioural tests employed, and some evidence of increased locomotor activity in some tests. An analysis of three separate human data sets revealed a gene wide association between variation in FBXL3 and bipolar disorder (P = 0.009).

Conclusions: Our results are consistent with previous studies of mutants with extended circadian periods and suggest that disruption of FBXL3 is associated with mania-like behaviours in both mice and humans.

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Related in: MedlinePlus

The corticosterone response to the forced swim test.A significant increase in plasma corticosterone level was seen following the forced swim (F = 160, P<0.0001) but there was no effect of genotype on either corticosterone level at baseline or in response to stress. (Data shown is mean ± SEM).
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pone-0038263-g004: The corticosterone response to the forced swim test.A significant increase in plasma corticosterone level was seen following the forced swim (F = 160, P<0.0001) but there was no effect of genotype on either corticosterone level at baseline or in response to stress. (Data shown is mean ± SEM).

Mentions: Following the first forced swim test, there was a significant increase in plasma corticosterone level (F = 211, P<0.0001), indicative of a stress response to the task. However, there was no effect of genotype on either baseline or the post-swim induced increase in plasma corticosterone level (Figure 4).


Reduced anxiety and depression-like behaviours in the circadian period mutant mouse afterhours.

Keers R, Pedroso I, Breen G, Aitchison KJ, Nolan PM, Cichon S, Nöthen MM, Rietschel M, Schalkwyk LC, Fernandes C - PLoS ONE (2012)

The corticosterone response to the forced swim test.A significant increase in plasma corticosterone level was seen following the forced swim (F = 160, P<0.0001) but there was no effect of genotype on either corticosterone level at baseline or in response to stress. (Data shown is mean ± SEM).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3376117&req=5

pone-0038263-g004: The corticosterone response to the forced swim test.A significant increase in plasma corticosterone level was seen following the forced swim (F = 160, P<0.0001) but there was no effect of genotype on either corticosterone level at baseline or in response to stress. (Data shown is mean ± SEM).
Mentions: Following the first forced swim test, there was a significant increase in plasma corticosterone level (F = 211, P<0.0001), indicative of a stress response to the task. However, there was no effect of genotype on either baseline or the post-swim induced increase in plasma corticosterone level (Figure 4).

Bottom Line: Variation in genes encoding components of the molecular circadian clock has been associated with increased risk of the disorder in clinical populations.Similarly in animal models, disruption of the circadian clock can result in altered mood and anxiety which resemble features of human mania; including hyperactivity, reduced anxiety and reduced depression-like behaviour.One such mutant, after hours (Afh), an ENU-derived mutant with a mutation in a recently identified circadian clock gene Fbxl3, results in a disturbed (long) circadian rhythm of approximately 27 hours.

View Article: PubMed Central - PubMed

Affiliation: MRC SGDP Centre, Institute of Psychiatry, King's College London, London, United Kingdom.

ABSTRACT

Background: Disruption of the circadian rhythm is a key feature of bipolar disorder. Variation in genes encoding components of the molecular circadian clock has been associated with increased risk of the disorder in clinical populations. Similarly in animal models, disruption of the circadian clock can result in altered mood and anxiety which resemble features of human mania; including hyperactivity, reduced anxiety and reduced depression-like behaviour. One such mutant, after hours (Afh), an ENU-derived mutant with a mutation in a recently identified circadian clock gene Fbxl3, results in a disturbed (long) circadian rhythm of approximately 27 hours.

Methodology: Anxiety, exploratory and depression-like behaviours were evaluated in Afh mice using the open-field, elevated plus maze, light-dark box, holeboard and forced swim test. To further validate findings for human mania, polymorphisms in the human homologue of FBXL3, genotyped by three genome wide case control studies, were tested for association with bipolar disorder.

Principal findings: Afh mice showed reduced anxiety- and depression-like behaviour in all of the behavioural tests employed, and some evidence of increased locomotor activity in some tests. An analysis of three separate human data sets revealed a gene wide association between variation in FBXL3 and bipolar disorder (P = 0.009).

Conclusions: Our results are consistent with previous studies of mutants with extended circadian periods and suggest that disruption of FBXL3 is associated with mania-like behaviours in both mice and humans.

Show MeSH
Related in: MedlinePlus