Lithium Effects on Circadian Rhythms

Engelmann, Wolfgang

doi:10.1007/978-3-642-72637-8_24

Cited by 10 publications

(11 citation statements)

References 35 publications

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“…The period lengthening effect by Li + ions was observed in many organisms (Engelmann, 1987;Iwahana et al, 2004;LakinThomas, 1993), including humans (Johnsson et al, 1979). Lithium compounds also play a significant pharmaceutical role in the treatment of bipolar disorder (Keck, 2004), which was tentatively related to lithium's period-lengthening effects in humans.…”

mentioning

confidence: 96%

Lithium Leads to an Increased FRQ Protein Stability and to a Partial Loss of Temperature Compensation in the Neurospora Circadian Clock

Jolma

Falkeid²,

Bamerni

et al. 2006

J Biol Rhythms

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In many organisms, the presence of lithium leads to an increase of the circadian period length. In Neurospora crassa, it was earlier found that lithium results in a decrease of overall growth and increased circadian periods. In this article, the authors show that lithium leads to a reduction of FRQ degradation with elevated FRQ levels and to a partial loss of temperature compensation. At a concentration of 13 mM lithium, FRQ degradation is reduced by about 60% while, surprisingly, the activity of the 20S proteasome remains unaffected. Experiments and model calculations have shown that the stability of FRQ is dependent on its phosphorylation state and that increased FRQ protein stabilities lead to increased circadian periods, consistent with the observed increase of the period when lithium is present. Because in Neurospora the proteasome activity is unaffected by lithium concentrations that lead to significant FRQ stabilization, it appears that lithium acts as an inhibitor of kinases that affect phosphorylation of FRQ and other proteins. A competition between Li(+) and Mg(2+) ions for Mg(2+)-binding sites may be a mechanism to how certain kinases are inhibited by Li(+). A possible kinase in this respect is GSK-3, which in other organisms is known to be inhibited by lithium. The partial loss of temperature compensation in the presence of lithium can be understood as an increase in the overall activation energy of FRQ degradation. This increase in activation energy may be related to a reduction in FRQ phosphorylation so that more kinase activity, that is, higher temperature and longer times, is required to achieve the necessary amount of FRQ phosphorylation leading to turnover. Using a modified Goodwin oscillator as a semiquantitative model for the Neurospora clock, the effects of lithium can be described by adding lithium inhibitory terms of FRQ degradation to the model.

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mentioning

confidence: 96%

Lithium Leads to an Increased FRQ Protein Stability and to a Partial Loss of Temperature Compensation in the Neurospora Circadian Clock

Jolma

Falkeid²,

Bamerni

et al. 2006

J Biol Rhythms

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“…Under lithium, mice maintain their normal circadian timekeeping related to vigilance level and basic emotional reactivity. From another biological perspective, the same conclusions were also reached: that this psychoactive drug could affect the X pacemaker rather than the Y modulator (Engelmann, 1987).…”

Section: Emerging Concepts In Psychophysiology and Comparative Psychomentioning

confidence: 52%

Evidence for Two Asynchronous Circadian Systems of Emotionality: Theoretical Aspects in Comparative Psychology

Poirel

1995

The Journal of General Psychology

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“…This lithium eect seems to be of a general nature and is not speci®c for circumnutation oscillations. Lithium ions aect circadian systems from humans to unicellular organisms (éstgaard et al 1982;Engelmann 1987). Stomatal oscillations with a period of about 30 min are aected (BrogaÊ rdh and Johnsson 1974) as well as leaf movements (Mayer and Hampp 1995).…”

Section: Some Cellular-physiological Approachesmentioning

confidence: 99%

Circumnutations: results from recent experiments on Earth and in space

Johnsson

1997

Planta

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Results of experiments on circumnutations from the last few decades are discussed, particularly in regard to the relationship between gravity and circumnutations. Pertinent and new results from experiments in microgravity as well as results from ground-based studies are summarized, and questions with relevance to space activities are posed. Theoretical approaches to describe aspects of circumnutation are also discussed. The review indicates some areas where further research efforts are needed.

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Lithium Effects on Circadian Rhythms

Cited by 10 publications

References 35 publications

Lithium Leads to an Increased FRQ Protein Stability and to a Partial Loss of Temperature Compensation in the Neurospora Circadian Clock

Lithium Leads to an Increased FRQ Protein Stability and to a Partial Loss of Temperature Compensation in the Neurospora Circadian Clock

Evidence for Two Asynchronous Circadian Systems of Emotionality: Theoretical Aspects in Comparative Psychology

Circumnutations: results from recent experiments on Earth and in space

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