Wheel-running activity rhythms in two inbred strains of laboratory rats under different photoperiods

Siebert, Ursula; Wollnik, Franziska

doi:10.1016/0031-9384(91)90574-8

Cited by 17 publications

(9 citation statements)

References 17 publications

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“…Previous investigations of LEW rats suggest that the unusual activity pattern of this strain is caused by a distinct coupling of multiple circadian oscillators (34,46,47). However, the neurophysiological or neurochemical mechanisms underlying the unusual activity pattern of the LEW strain are still unknown.…”

Section: Discussionmentioning

confidence: 97%

“…These strains have rather unusual activity patterns that may be caused by multiple circadian oscillators coupled to each other with a phase relationship of 4-6 h (34,(46)(47)(48). The goal of the study was to investigate the effects of various antidepressant drugs on the circadian wheelrunning rhythms of the two strains compared to strain ACI, which shows an activity pattern found in most laboratory rats.…”

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confidence: 99%

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Effects of chronic administration and withdrawal of antidepressant agents on circadian activity rhythms in rats

Wollnik

1992

Pharmacology Biochemistry and Behavior

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WOLLNIK, F. E;ffects of chronic administration and Withdrawal of antidepressant agents on circadian activity rhythms in rats.PHARMACOL BIOCHEM BEHAV 43{2) S49-S61, 1992.-Experimental and clinical studies indicate that clinical depression may be associated with disturbances of circadian rhythms. To explore the interaction between circadian rhythmicity, behavioral state, and monoaminergic systems, the present study investigated the effects of chronic administration and withdrawal of the following antidepressant agents on circadian wheel-running rhythms of laboratory rats: a) moclobemide, a reversible and selective monoamine oxidase (MAO) type A inhibitor; b) Ro 19-6327, a selective MAO type B inhibitor; c) desipramine, a preferential norepinephrine reuptalce inhibitor; d) clomipramine and e) fluoxetine, both serotonin reuptake inhibitors; and f) levoprotillne, an atypical antidepressant whose biochemical mechanism is still unknown. Wheel-running activity rhythms were studied in three inbred strains of laboratory rats (ACI, BH, LEW) under constant darkness (DD). Two of these inbred strains (BH and LEW) show proround abnormalities in their circadian activity rhythms, namely, a reduced overall level of activity and bimodal or multimodal activity patterns. Chronic treatment with moclobemide and desipramine consistently increased the overall level, as well as the circadian amplitude, of the activity rhythm. Furthermore, the abnormal activity pattern of the LEW strain was changed into a unimodal activity pattern like that of other laboratory rats. The free-running period r was slightly shortened by moclobemide and dramatically shonened by desipramine. Effects of moclobemide and desipramine treatment on overall activity level and duration were reversed shortly after termination of treatment, whereas long aftereffects were observed for the free-running period. All other substances tested had no systematic effects on the activity rhythms of any of the strains. The fact that moclobemide and desipramine altered the period, amplitude, and pattern of circadian activity rhythms is consistent with the hypothesis that monoaminergic transmitters play a significant role in the neuronal control of behavioral state and circadian rhythmicity. Although the present study found that some antidepressives affect parameters of circadian rhythmicity, it could not demonstrate a common effect of all classes of antidepressives. Circadian rhythmsGenetic differences Inbred strains Antidepressives Moclobemide Ro 19-6327 Desipramine Clomipramine Fluoxetine Levoprotiline IT has often been suggested that there is an association between the pathophysiology of affective disorders and disturbances of circadian rhythms. For example, studies in humans have shown that affective disorders are associated with abnormalities in the period, phase, and/or amplitude of physiological, behavioral, and endocrine rhythms, resulting in quite a number of different hypotheses on the chronobiology of depression (16,18,20,39,41). Special attention has been paid to the ob...

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Section: Discussionmentioning

confidence: 97%

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confidence: 99%

Effects of chronic administration and withdrawal of antidepressant agents on circadian activity rhythms in rats

Wollnik

1992

Pharmacology Biochemistry and Behavior

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“…2), but were nearly completely absent in rats [26], which unlike hamsters, are minimally responsive to seasonal variations in day length [27]. …”

Section: Discussionmentioning

confidence: 99%

Sex differences in Siberian hamster ultradian locomotor rhythms

Prendergast

Stevenson

Zucker

2013

Physiology & Behavior

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Sex differences in ultradian activity rhythms (URs) and circadian rhythms (CRs) were assessed in Siberian hamsters kept in long day (LD) or short day (SD) photoperiods for 40 weeks. For both sexes URs of locomotor activity were more prevalent, greater in amplitude and more robust in SDs. The UR period was longer in females than males in both day lengths. The reproductive system underwent regression and body mass declined during the initial 10 weeks of SD treatment, and in both sexes these traits spontaneously reverted to the LD phenotype at or before 40 weeks in SD, reflecting the development of neuroendocrine refractoriness to SD patterns of melatonin secretion. Hamsters of both sexes, however, continued to display SD-like URs at the 40 weeks time point. CRs were less prevalent and the waveform less robust and lower in amplitude in SDs than LDs; the SD circadian waveform also did not revert to the long-day phenotype after 40 weeks of SD treatment. Short day lengths enhanced ultradian and diminished circadian rhythms in both sexes. Day length controls several UR characteristics via gonadal steroid and melatonin-independent mechanisms. Sex differences in ultradian timing may contribute to sex diphenisms in rhythms of sleep, food intake and exercise.

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“…These highly synchronizing conditions could account for the absence of a differentiated development. The study by Siebert and Wollnik (1991) has indicated that in rats 3-6 weeks of age, the phase relationship between individual activity bouts may be modified by LD cycles of different photoperiods; this modification was not observed in adults. This experiment thus demonstrated the fragility and plasticity of the system at an early stage.…”

Section: Discussionmentioning

confidence: 91%

Neonatal Exposure to Atypical Zeitgeber in the Wistar Rat. Effects on Development of Circadian Rhythms of Drinking and Motor Activities

Schelstraete¹,

Dutilleul²,

Weyers³

1997

Biological Rhythm Research

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The data described concern the maturation of circadian motor and drinking rhythms immediately after weaning. We ran two experiments in both of which mother rats and their litters were subjected to either an atypical Zeitgeber or to standard conditions from the birth of the young up to weaning on the 19th day. In the experimental groups, the light and the temperature cycles were permanently in phase opposition and were shifted by 12 hours every 3 days. In the control groups, the cycles were the same except that they were in phase and were never shifted. In the first experiment, after weaning the young were subjected to an LD cycle; in the second experiment to constant conditions. The results of both experiments showed that the circadian rhythms of drinking and locomotor activities appeared with a delay of ten days in the experimental rats. These rats kept an ultradian structure for a longer time. During the constant conditions, a lengthening (around 25 min.) of the free-running period was observed. In conclusion, atypical environmental cycles during early neonatal life affect the development of the circadian system.

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Wheel-running activity rhythms in two inbred strains of laboratory rats under different photoperiods

Cited by 17 publications

References 17 publications

Effects of chronic administration and withdrawal of antidepressant agents on circadian activity rhythms in rats

Effects of chronic administration and withdrawal of antidepressant agents on circadian activity rhythms in rats

Sex differences in Siberian hamster ultradian locomotor rhythms

Neonatal Exposure to Atypical Zeitgeber in the Wistar Rat. Effects on Development of Circadian Rhythms of Drinking and Motor Activities

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