Aging and photoperiod affect entrainment and quantitative aspects of locomotor behavior in Syrian hamsters

1997 ◽  
Vol 272 (4) ◽  
pp. R1219-R1225 ◽  
Author(s):  
K. Scarbrough ◽  
S. Losee-Olson ◽  
E. P. Wallen ◽  
F. W. Turek

Aging affects the regulation of diurnal and circadian rhythmicity. We tested the hypothesis that the age-related difference in the phase angle of entrainment of the locomotor activity rhythm to a light-dark (LD) cycle would be greater under LD 6:18 than LD 14:10. We also analyzed changes in quantitative aspects of wheel-running behavior according to age group. Young (9-wk-old), middle-aged (11- to 12-mo-old), and old (15- to 17-mo-old) male golden hamsters were entrained to a 14:10 LD cycle followed by re-entrainment to a 6:18 LD cycle. Fourteen days after the start of locomotor recording in LD 14:10 and again after 27 days in LD 6:18, the phase of activity onset, the total number of wheel revolutions performed per day, the peak intensity of wheel-running activity, the duration of the active period, and the level of fragmentation of locomotor activity were quantitated. We also studied the temporal distribution of the largest bout of wheel-running activity among the age groups in both photoperiods. Short days induced testicular regression at a similar rate among young, middle-aged, and old hamsters. The data are discussed in terms of the effects of age on overall circadian organization in the seasonally changing environment.

2000 ◽  
Vol 279 (2) ◽  
pp. R586-R590 ◽  
Author(s):  
Marilyn J. Duncan ◽  
Anthony W. Deveraux

Aging involves many alterations in circadian rhythms, including a loss of sensitivity to both photic and nonphotic time signals. This study investigated the sensitivity of young and old hamsters to the phase advancing effect of a 6-h dark pulse on the locomotor activity rhythm. Each hamster was tested four times during a period of ∼9 mo; periods of exposure to a 14-h photoperiod were alternated with the periods of exposure to constant light (20–80 lx), during which the dark pulses were administered. There was no significant difference in the phase shifts exhibited by the young (4–10 mo) and old hamsters (19–25 mo) or in the amount of wheel running activity displayed during each dark pulse. However, young hamsters had a significantly greater propensity to exhibit split rhythms immediately after the dark pulses. These results suggest that, although aging does not reduce the sensitivity of the circadian pacemaker to this nonphotic signal, it alters one property of the pacemaker, i.e., the flexibility of the coupling of its component oscillators.


1992 ◽  
Vol 263 (5) ◽  
pp. R1099-R1103 ◽  
Author(s):  
P. C. Zee ◽  
R. S. Rosenberg ◽  
F. W. Turek

The phase angle of entrainment of the circadian rhythm of the locomotor activity rhythm to a light-dark (LD) cycle was examined in young (2-5 mo old) and middle-aged (13-16 mo old) hamsters. An age-related phase advance in the onset of locomotor activity relative to lights off was seen during stable entrainment to a 14:10-h LD cycle. In addition, the effects of age on the rate of reentrainment of the circadian rhythm of locomotor activity were examined by subjecting young and middle-aged hamsters to either an 8-h advance or delay shift of the LD cycle. Middle-aged hamsters resynchronized more rapidly after a phase advance of the LD cycle than did young hamsters, whereas young hamsters were able to phase delay more rapidly than middle-aged hamsters. The age-related phase advance of activity onset under entrained conditions, and the alteration of responses in middle-aged hamsters reentraining to a phase-shifted LD cycle, may be due to the shortening of the free-running period of the circadian rhythm of locomotor activity with advancing age that has previously been observed in this species.


2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S872-S872
Author(s):  
Ted G Graber ◽  
Rosario Marota ◽  
Jill Thompson ◽  
Steve Widen ◽  
Blake Rasmussen

Abstract One inevitable consequence of the effect of age on our bodies is the graduated deterioration of physical function and exercise capacity, driven, in part by the adverse effect of age on muscle tissue. Our primary purpose was to determine the relationship between patterns of gene expression in skeletal muscle and loss of physical function. We hypothesized that some genes that change expression with age would correlate with functional decline, or conversely with preservation of function. Male C57Bl/6 mice [adults (6-7 months old, n=9), older (24-25 months old, n=9), and elderly (28+ months of age, n=9) were tested for physical ability using a comprehensive functional assessment battery [CFAB, a composite scoring system: comprised of the rotarod (overall motor function), grip strength (fore-limb strength), inverted cling (4-limb strength/endurance), voluntary wheel running (activity rate/volitional exercise), and treadmill tests (endurance)]. We extracted RNA from the tibialis anterior muscles, ran RNAseq to examine the transcriptome using an Illumina NextSeq 550, comparing adults (n=7) to older (n=7) and elderly mice (n=9). Age resulted in gene expression differences of 1.5 log2 fold change or greater (p<0.01) in 46 genes in the older mice and in 252 genes in the elderly (both compared to adults). Current ongoing work is examining the physiological relevance of these genes to age-related loss of physical function. We are in the process of using linear regression to determine which of the genes with age-related changes in expression are associated (R>0.5 and p<0.05) with functional status as measured by CFAB.


2005 ◽  
Vol 289 (4) ◽  
pp. R998-R1005 ◽  
Author(s):  
Juan J. Chiesa ◽  
Montserrat Anglès-Pujolràs ◽  
Antoni Díez-Noguera ◽  
Trinitat Cambras

Both temporary access to a running wheel and temporary exposure to light systematically influence the phase producing entrainment of the circadian activity rhythm in the golden hamster ( Mesocricetus auratus). However, precise determination of entrainment limits remains methodologically difficult, because such calculations may be influenced by varying experimental paradigms. In this study, effects on the entrainment of the activity pattern during successive light-dark (LD) cycles of stepwise decreasing periods, as well as wheel running activity, were investigated. In particular, the hamster activity rhythm under LD cycles with a period (T) shorter than 22 h was studied, i.e., when the LD cycle itself had been shown to be an insufficiently strong zeitgeber to synchronize activity rhythms. Indeed, it was confirmed that animals without a wheel do not entrain under 11:11-h LD cycles (T = 22 h). Subsequently providing hamsters continuous access to a running wheel established entrainment to T = 22 h. Moreover, this paradigm underwent further reductions of the T period to T = 19.6 h without loss of entrainment. Furthermore, restricting access to the wheel did not result in loss of entrainment, while even entrainment to T = 19 h was observed. To explain this observed shift in the lower entrainment limit, our speculation centers on changes in pacemaker response facilitated by stepwise changes of T spaced very far apart, thus allowing time for adaptation.


1997 ◽  
Vol 273 (6) ◽  
pp. R2132-R2137 ◽  
Author(s):  
Plamen D. Penev ◽  
Phyllis C. Zee ◽  
Fred W. Turek

The continuous monitoring of spontaneous locomotor activity has emerged as one of the most widely used metrics in rodent circadian research. This behavioral measure is also extremely useful for the description of the effects of aging on circadian rhythms. The present study describes the successful use of a log-survivorship approach to identify discrete bouts of hamster wheel-running activity and provides a detailed description of the age-related fragmentation in the 24-h profile of this behavioral variable. In addition, stepwise discriminant analysis identified the most important quantitative measures for distinguishing between the individual patterns of wheel-running activity of young (3 mo) and old (17–18 mo) golden hamsters. The results suggest that this method of bout analysis can be a valuable tool for the study of genetic, developmental, neurochemical, physiological, and environmental factors involved in the temporal control of rodent locomotor behavior.


1982 ◽  
Vol 242 (3) ◽  
pp. R261-R264 ◽  
Author(s):  
P. W. Cheung ◽  
C. E. McCormack

These experiments were undertaken to determine if the pineal gland is involved in the physiological mechanism by which the rat alters its free-running period (tau) in response to changes in illuminance. Spontaneous wheel-running activity was recorded from pinealectomized or sham-operated female Charles River rats. The tau of running activity was determined in continuous darkness (DD) or in continuous dim light (LL). Pinealectomized rats and sham-operated rats lengthened their tau's to approximately the same extent when shifted from DD to LL and shortened their tau's when shifted back to DD. Continuous melatonin administration via Silastic capsules failed to alter tau of rats kept in dim LL. These results indicate that the pineal is not primarily involved in the mechanism by which the rat alters tau in response to changes in illuminance.


1998 ◽  
Vol 275 (4) ◽  
pp. R960-R968 ◽  
Author(s):  
Fred C. Davis ◽  
N. Viswanathan

The causes of age-related disruptions in the timing of human sleep and wakefulness are not known but may include changes in both the homeostatic and circadian regulation of sleep. In Syrian hamsters the free running period of the circadian activity/rest rhythm has been reported to shorten with age. Although this has been observed under a variety of experimental conditions, the changes have been small and their consistency uncertain. In the present study, the wheel running activity/rest rhythm was continuously measured in male Syrian hamsters ( Mesocricetus auratus) in dim constant light (<1 lx) from 8 wk of age until death. Fifteen hamsters survived to at least 90 wk (28%). The average free running period of these hamsters did not change with age. In 18 hamsters that died between 50 and 88 wk, free running period also did not change before death. In contrast to free running period, other measures related to activity level changed significantly with age and before death. Despite changes in the expression of the activity/rest rhythm, the free running period of the hamster circadian pacemaker remained remarkably stable with age.


2011 ◽  
Vol 300 (3) ◽  
pp. R519-R530 ◽  
Author(s):  
Jens Hannibal ◽  
Hansen M. Hsiung ◽  
Jan Fahrenkrug

Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD) cycle. The neuropeptide vasoactive intestinal polypetide (VIP) and its receptor (VPAC2) are highly expressed in the SCN. Recent studies indicate that VIPergic signaling plays an essential role in the maintenance of ongoing circadian rhythmicity by synchronizing SCN cells and by maintaining rhythmicity within individual neurons. To further increase the understanding of the role of VPAC2 signaling in circadian regulation, we implanted telemetric devices and simultaneously measured core body temperature, spontaneous activity, and heart rate in a strain of VPAC2-deficient mice and compared these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ∼4–6 h prior to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral parameters, especially when animals have altered circadian phenotype.


1997 ◽  
Vol 273 (6) ◽  
pp. R1957-R1964 ◽  
Author(s):  
Verónica S. Valentinuzzi ◽  
Kathryn Scarbrough ◽  
Joseph S. Takahashi ◽  
Fred W. Turek

The effects of age on the circadian clock system have been extensively studied, mainly in two rodent species, the laboratory rat and the golden hamster. However, less information is available on how aging alters circadian rhythmicity in a commonly studied rodent animal model, the mouse. Therefore, in the present study we compared the rhythm of wheel-running activity in adult (6–9 mo) and old (19–22 mo) C57BL/6J mice maintained under different lighting conditions for a period of 4 mo. During this period, mice were subjected to phase advances and phase delays of the light-dark (LD) cycle and eventually to constant darkness (DD). In LD (12 h light, 12 h dark), old mice exhibited delayed activity onset relative to light offset and an increase in the variability of activity onset compared with adult mice. After a 4-h phase advance of the LD cycle, old mice took significantly longer to reentrain their activity rhythm when compared with adult animals. Old mice also demonstrated a decline in the number of wheel revolutions per day and a tendency toward a decrease in the length of the active phase. An increase in fragmentation of activity across the 24-h day was obvious in aging animals, with bouts of activity being shorter and longer rest periods intervening between them. No age difference was detected in the maximum intensity of wheel-running activity. In DD, the free-running period was significantly longer in old mice compared with adults. In view of the rapidly expanding importance of the laboratory mouse for molecular and genetic studies of the mammalian nervous system, the present results provide a basis at the phenotypic level to begin to apply genetic methods to the analysis of circadian rhythms and aging in mammals.


1998 ◽  
Vol 274 (3) ◽  
pp. R830-R839 ◽  
Author(s):  
Susan E. Labyak ◽  
Fred W. Turek ◽  
Edward P. Wallen ◽  
Phyllis C. Zee

Syrian hamsters display age-related changes in the expression of circadian rhythms and in responsiveness of the circadian system to photic and nonphotic stimuli. This study characterized the effects of age on the locomotor activity rhythm of middle-aged and old hamsters and evaluated the effects of strengthening the entraining light signal. Compared with young (4.5 mo) animals, middle-aged (11.25 mo) and old (16 mo) animals displayed increased daily bouts of activity ( P < 0.001) and reduced total daily activity and activity rhythm amplitude ( P < 0.05) in 14:10-h light-dark cycles. After the light intensity was increased from 300 to 1,500 lx during the light cycle, middle-aged hamsters demonstrated decreased daily activity bouts ( P < 0.05) and increased total daily activity ( P ≤ 0.01) and activity rhythm amplitude ( P≤ 0.001) compared with controls maintained in 300 lx. The pattern of changes in the activity rhythm of old experimental animals was similar to trends observed in middle-aged experimental hamsters, although not as robust. Thus age-related changes in the activity rhythm are occurring by middle age in hamsters, and the provision of stronger entraining signals may lead to more stable circadian organization.


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