scholarly journals Drugs of Abuse Can Entrain Circadian Rhythms

2007 ◽  
Vol 7 ◽  
pp. 203-212 ◽  
Author(s):  
Ann E. K. Kosobud ◽  
Andrea G. Gillman ◽  
Joseph K. Leffel ◽  
Norman C. Pecoraro ◽  
G. V. Rebec ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Drug Metabolism ◽  
Suprachiasmatic Nucleus ◽  
Drugs Of Abuse ◽  
Social Cues ◽  
Dark Cycle ◽  
Drug Reward ◽  
Locomotor Stimulation ◽  
Almost All

Circadian rhythms prepare organisms for predictable events during the Earth's 24-h day. These rhythms are entrained by a variety of stimuli. Light is the most ubiquitous and best known zeitgeber, but a number of others have been identified, including food, social cues, locomotor activity, and, most recently drugs of abuse. Given the diversity of zeitgebers, it is probably not surprising that genes capable of clock functions are located throughout almost all organs and tissues. Recent evidence suggests that drugs of abuse can directly entrain some circadian rhythms. We have report here that entrainment by drugs of abuse is independent of the suprachiasmatic nucleus and the light/dark cycle, is not dependent on direct locomotor stimulation, and is shared by a variety of classes of drugs of abuse. We suggest that drug-entrained rhythms reflect variations in underlying neurophysiological states. This could be the basis for known daily variations in drug metabolism, tolerance, and sensitivity to drug reward. These rhythms could also take the form of daily periods of increased motivation to seek and take drugs, and thus contribute to abuse, addiction and relapse.

Internal synchronization among several circadian rhythms in rats under constant light

1978 ◽  
Vol 235 (5) ◽  
pp. R243-R249 ◽  
Author(s):  
K. I. Honma ◽  
T. Hiroshige
Keyword(s):  
Locomotor Activity ◽  
Body Temperature ◽  
Circadian Rhythms ◽  
Continuous Light ◽  
Biological Rhythms ◽  
Plasma Corticosterone ◽  
Dark Cycle ◽  
Internal Oscillator ◽  
Free Running ◽  
Phase Angles

Three biological rhythms (locomotor activity, body temperature, and plasma corticosterone) were measured simultaneously in individual rats under light-dark cycles and continuous light. Spontaneous locomotor activity was recorded on an Animex and body temperature was telemetrically monitored throughout the experiments. Blood samples were obtained serially at 2-h intervals on the experimental days. Phase angles of these rhythms were calculated by a least-squares spectrum analysis. Under light-dark cycles, the acrophases of locomotor activity, body temperature, and plasma corticosterone were found at 0029, 0106, and 1940 h, respectively. When rats were exposed to 200 lx continuous light, locomotor activity and body temperature showed free-running rhythms with a period of 25.2 h on the average. Plasma corticosterone levels determined at 12 days after exposure to continuous light exhibited a circadian rhythm with the acrophase shifted to 0720. The acrophases of locomotor activity and body temperature, determined simultaneously on the same day, were found to be located at 1303 and 1358 h, respectively. Phase-angle differences among the three rhythms on the 12th day of continuous light were essentially the same with those under the light-dark cycle. These results suggest that circadian rhythms of locomotor activity, body temperature, and plasma corticosterone are most probably coupled to a common internal oscillator in the rat.

Adaptation of circadian rhythmicity to shift in light-dark cycle accelerated by a benzodiazepine

1987 ◽  
Vol 253 (1) ◽  
pp. R204-R207 ◽  
Author(s):  
O. van Reeth ◽  
F. W. Turek
Keyword(s):  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Abrupt Change ◽  
Single Injection ◽  
Activity Rhythm ◽  
Circadian Rhythmicity ◽  
Dark Cycle ◽  
Short Acting ◽  
Locomotor Activity Rhythm ◽  
Human Circadian Rhythms

The light-dark cycle is the major synchronizing agent for circadian rhythms in animals. After an abrupt shift in the light-dark cycle, it usually takes many days for circadian rhythms to resynchronize. A single injection of the short-acting benzodiazepine, triazolam, to hamsters subjected to an 8-h advance of the light-dark cycle resulted in an approximately 50% reduction in the time taken for the circadian locomotor activity rhythm to be resynchronized to the new lighting schedule. These results suggest that it may be possible to use drugs to facilitate the resynchronization of human circadian rhythms following an abrupt change in environmental time.

scholarly journals Neural Mechanisms of Circadian Regulation of Natural and Drug Reward

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Lauren M. DePoy ◽  
Colleen A. McClung ◽  
Ryan W. Logan
Keyword(s):  
Circadian Rhythms ◽  
Drugs Of Abuse ◽  
Neural Circuitry ◽  
Circadian System ◽  
Neural Mechanisms ◽  
Drug Reward ◽  
Reward Function ◽  
Timing System ◽  
Circadian Timing System ◽  
Negative Health Outcomes

Circadian rhythms are endogenously generated near 24-hour variations of physiological and behavioral functions. In humans, disruptions to the circadian system are associated with negative health outcomes, including metabolic, immune, and psychiatric diseases, such as addiction. Animal models suggest bidirectional relationships between the circadian system and drugs of abuse, whereby desynchrony, misalignment, or disruption may promote vulnerability to drug use and the transition to addiction, while exposure to drugs of abuse may entrain, disrupt, or perturb the circadian timing system. Recent evidence suggests natural (i.e., food) and drug rewards may influence overlapping neural circuitry, and the circadian system may modulate the physiological and behavioral responses to these stimuli. Environmental disruptions, such as shifting schedules or shorter/longer days, influence food and drug intake, and certain mutations of circadian genes that control cellular rhythms are associated with altered behavioral reward. We highlight the more recent findings associating circadian rhythms to reward function, linking environmental and genetic evidence to natural and drug reward and related neural circuitry.

scholarly journals IA Channels Encoded by Kv1.4 and Kv4.2 Regulate Neuronal Firing in the Suprachiasmatic Nucleus and Circadian Rhythms in Locomotor Activity

2012 ◽  
Vol 32 (29) ◽  
pp. 10045-10052 ◽  
Author(s):  
D. Granados-Fuentes ◽  
A. J. Norris ◽  
Y. Carrasquillo ◽  
J. M. Nerbonne ◽  
E. D. Herzog
Keyword(s):  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Suprachiasmatic Nucleus ◽  
Neuronal Firing

Identification of the suprachiasmatic nucleus in birds

2001 ◽  
Vol 280 (4) ◽  
pp. R1185-R1189 ◽  
Author(s):  
Takashi Yoshimura ◽  
Shinobu Yasuo ◽  
Yoshikazu Suzuki ◽  
Eri Makino ◽  
Yuki Yokota ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Circadian Clock ◽  
Suprachiasmatic Nucleus ◽  
Japanese Quail ◽  
Clock Genes ◽  
Biological Clock ◽  
Circadian Oscillators ◽  
Circadian Clock Genes ◽  
Dim Light

Circadian rhythms are generated by an internal biological clock. The suprachiasmatic nucleus (SCN) in the hypothalamus is known to be the dominant biological clock regulating circadian rhythms in mammals. In birds, two nuclei, the so-called medial SCN (mSCN) and the visual SCN (vSCN), have both been proposed to be the avian SCN. However, it remains an unsettled question which nuclei are homologous to the mammalian SCN. We have identified circadian clock genes in Japanese quail and demonstrated that these genes are expressed in known circadian oscillators, the pineal and the retina. Here, we report that these clock genes are expressed in the mSCN but not in the vSCN in Japanese quail, Java sparrow, chicken, and pigeon. In addition, mSCN lesions eliminated or disorganized circadian rhythms of locomotor activity under constant dim light, but did not eliminate entrainment under light-dark (LD) cycles in pigeon. However, the lesioned birds became completely arrhythmic even under LD after the pineal and the eye were removed. These results indicate that the mSCN is a circadian oscillator in birds.

scholarly journals Entrainment of circadian rhythms of locomotor activity by ambient temperature cycles in the dromedary camel

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hicham Farsi ◽  
Mohamed R. Achaâban ◽  
Mohammed Piro ◽  
Béatrice Bothorel ◽  
Mohammed Ouassat ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Body Temperature ◽  
Circadian Rhythms ◽  
Ambient Temperature ◽  
Cycle Phase ◽  
Dromedary Camel ◽  
Dark Cycle ◽  
Free Running ◽  
Activity Onset ◽  
Master Clock

Abstract In the dromedary camel, a well-adapted desert mammal, daily ambient temperature (Ta)-cycles have been shown to synchronize the central circadian clock. Such entrainment has been demonstrated by examining two circadian outputs, body temperature and melatonin rhythms. Locomotor activity (LA), another circadian output not yet investigated in the camel, may provide further information on such specific entrainment. To verify if daily LA is an endogenous rhythm and whether the desert Ta-cycle can entrain it, six dromedaries were first kept under total darkness and constant-Ta. Results showed that the LA rhythm free runs with a period of 24.8–24.9 h. After having verified that the light–dark cycle synchronizes LA, camels were subjected to a Ta-cycle with warmer temperatures during subjective days and cooler temperatures during subjective nights. Results showed that the free-running LA rhythm was entrained by the Ta-cycle with a period of exactly 24.0 h, while a 12 h Ta-cycle phase advance induced an inversion of the LA rhythm and advanced the acrophase by 9 h. Similarly, activity onset and offset were significantly advanced. All together, these results demonstrate that the Ta-cycle is a strong zeitgeber, able to entrain the camel LA rhythm, hence corroborating previous results concerning the Ta non-photic synchronization of the circadian master clock.

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