Effects of aging on entrainment and rate of resynchronization of circadian locomotor activity

1992 ◽  
Vol 263 (5) ◽  
pp. R1099-R1103 ◽  
Author(s):  
P. C. Zee ◽  
R. S. Rosenberg ◽  
F. W. Turek
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Activity Rhythm ◽  
Phase Advance ◽  
Middle Aged ◽  
Age Related ◽  
Free Running ◽  
Effects Of Aging ◽  
Free Running Period ◽  
Related Phase

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.

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
Keyword(s):  
Locomotor Activity ◽  
Wheel Running ◽  
Activity Rhythm ◽  
Age Groups ◽  
Temporal Distribution ◽  
Similar Rate ◽  
Middle Aged ◽  
Running Activity ◽  
Age Related ◽  
Wheel Running Activity

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.

scholarly journals Effects of bright light on age-related changes in the locomotor activity of Syrian hamsters

1998 ◽  
Vol 274 (3) ◽  
pp. R830-R839 ◽  
Author(s):  
Susan E. Labyak ◽  
Fred W. Turek ◽  
Edward P. Wallen ◽  
Phyllis C. Zee
Keyword(s):  
Locomotor Activity ◽  
Daily Activity ◽  
Activity Rhythm ◽  
Bright Light ◽  
Light Signal ◽  
Light Cycle ◽  
Middle Aged ◽  
Syrian Hamsters ◽  
Age Related ◽  
Age Related Changes

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.

Are membrane properties essential for the circadian rhythm of Gonyaulax?

1984 ◽  
Vol 247 (2) ◽  
pp. R250-R256
Author(s):  
H. G. Scholubbers ◽  
W. Taylor ◽  
L. Rensing
Keyword(s):  
Circadian Rhythm ◽  
Phase Shift ◽  
Fluorescence Polarization ◽  
The Other ◽  
Membrane Properties ◽  
Response Curves ◽  
Whole Cells ◽  
Different Temperatures ◽  
Free Running ◽  
Free Running Period

Membrane properties of whole cells of Gonyaulax polyedra were measured by fluorescence polarization. Circadian changes of fluorescence polarization exist in exponentially growing cultures. They show an amplitude larger than that of stationary cultures, indicating that a part of the change is due to or amplified by an ongoing cell cycle. Measurements of parameters of the circadian glow rhythm were analyzed for possible correlation with the membrane data. Considerable differences (Q10 = 2.5-3.0) in fluorescence polarization were found in cultures kept at different temperatures ranging from 15 to 27.5 degrees C. The free-running period length at different temperatures, on the other hand, differed only slightly (Q10 = 0.9-1.1). Stationary cultures showed higher fluorescence polarization compared with growing cultures, whereas the free-running period lengths did not differ in cultures of various densities and growth rates. Temperature steps of different sign changed the fluorescence polarization slightly in different directions. The phase shift of 4-h pulses (-5, -9, +7 degrees C) resulted in maximal phase advances of 4, 6, and 2 h, respectively. The phasing of the phase-response curves was identical in all these experiments, a finding not to be expected if the pulses act via the measured membrane properties. Pulses of drugs that change the fluorescence polarization (e.g., chlorpromazine and lidocaine) did not or only slightly phase-shift the circadian rhythm.

Gonadal hormones organize and modulate the circadian system of the rat

1981 ◽  
Vol 241 (1) ◽  
pp. R62-R66 ◽  
Author(s):  
H. E. Albers
Keyword(s):  
Testosterone Propionate ◽  
Wheel Running ◽  
Activity Rhythm ◽  
Gonadal Hormones ◽  
Circadian System ◽  
Female Rats ◽  
Constant Darkness ◽  
Before And After ◽  
Free Running ◽  
Free Running Period

The circadian wheel-running rhythms of gonadectomized adult male, female, and perinatally androgenized female rats, maintained in constant darkness, were examined before and after implantation of Silastic capsules containing cholesterol (C) or estradiol-17 beta (E). The free-running period of the activity rhythm (tau) before capsule implantation tended to be shorter in animals exposed to perinatal androgen. Administration of C did not reliably alter tau in any group. E significantly shortened tau in 100% of females injected with oil on day 3 of life. In females, injected with 3.5 micrograms testosterone propionate on day 3, and males, E shortened or lengthened tau, with the direction and magnitude of this change in tau inversely related to the length of the individual's pretreatment tau. These data indicate that the presence of perinatal androgen does not eliminate the sensitivity of the circadian system of the rat to estrogen, since estrogen alters tau in a manner that depends on its pretreatment length.

Neuropeptide F immunoreactive clock neurons modify evening locomotor activity and free-running period in Drosophila melanogaster

2012 ◽  
Vol 520 (5) ◽  
pp. 970-987 ◽  
Author(s):  
Christiane Hermann ◽  
Taishi Yoshii ◽  
Verena Dusik ◽  
Charlotte Helfrich-Förster
Keyword(s):  
Drosophila Melanogaster ◽  
Locomotor Activity ◽  
Free Running ◽  
Neuropeptide F ◽  
Free Running Period

Variation in the naturally occurring rhythm of the estuarine amphipod, Corophium volutator (Pallas)

1983 ◽  
Vol 63 (4) ◽  
pp. 833-850 ◽  
Author(s):  
Walter F. Holmström ◽  
Elfed Morgan
Keyword(s):  
Activity Rhythm ◽  
Time Lapse ◽  
Early Summer ◽  
Corophium Volutator ◽  
Use Of Time ◽  
Recording Conditions ◽  
Free Running ◽  
Endogenous Activity ◽  
Free Running Period ◽  
Time Lapse Photography

The endogenous activity rhythm of the estuarine amphipod Corophium volutator has been studied by direct observation and with the use of time lapse photography. The rhythm persists under constant conditions having a free running period of between 12 and 13 h, and with activity maxima occurring during the early ebb. Freshly collected animals show a rhythm which is modulated on a semi-lunar basis, the activity maxima being attenuated during the neap tide periods, and the rhythm has also been found to vary in definition throughout the year. The activity pattern is most clearly denned in early summer and autumn, the population becoming arrhythmic during the winter months. The rhythm is relatively unaffected by the ambient light intensity and temperature of the recording conditions, and is evident in all post-natal stages of development. The possibility of mutual entrainment is discussed.

Sign in / Sign up

Export Citation Format

Share Document