1
|
Yousefzadehfard Y, Wechsler B, DeLorenzo C. Human circadian rhythm studies: Practical guidelines for inclusion/exclusion criteria and protocol. Neurobiol Sleep Circadian Rhythms 2022; 13:100080. [PMID: 35989718 PMCID: PMC9382328 DOI: 10.1016/j.nbscr.2022.100080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/03/2022] Open
Abstract
As interest in circadian rhythms and their effects continues to grow, there is an increasing need to perform circadian studies in humans. Although the constant routine is the gold standard for these studies, there are advantages to performing more naturalistic studies. Here, a review of protocols for such studies is provided along with sample inclusion and exclusion criteria. Sleep routines, drug use, shift work, and menstrual cycle are addressed as screening considerations. Regarding protocol, best practices for measuring melatonin, including light settings, posture, exercise, and dietary habits are described. The inclusion/exclusion recommendations and protocol guidelines are intended to reduce confounding variables in studies that do not involve the constant routine. Given practical limitations, a range of recommendations is provided from stringent to lenient. The scientific rationale behind these recommendations is discussed. However, where the science is equivocal, recommendations are based on empirical decisions made in previous studies. While not all of the recommendations listed may be practical in all research settings and with limited potential participants, the goal is to allow investigators to make well informed decisions about their screening procedures and protocol techniques and to improve rigor and reproducibility, in line with the objectives of the National Institutes of Health.
Collapse
Affiliation(s)
- Yashar Yousefzadehfard
- Center for Understanding Biology Using Imaging Technology, Department of Psychiatry, Stony Brook University, Stony Brook, NY, USA.,Department of Psychiatry, Texas Tech University Health Science Center, Midland, TX, USA
| | - Bennett Wechsler
- Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, USA
| | - Christine DeLorenzo
- Center for Understanding Biology Using Imaging Technology, Department of Psychiatry, Stony Brook University, Stony Brook, NY, USA
| |
Collapse
|
2
|
Ramdhany YD, Devi Goorah SS, Cheeneebash J, Niketan Oodun R. Factors Associated with Poor Sleep among Young People in Mauritius: A Survey-Based Study. INTERNATIONAL JOURNAL OF MEDICAL STUDENTS 2022. [DOI: 10.5195/ijms.2022.654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Poor sleep quality in young people is a global concern. This study was conducted to explore sleep quality and its contributory factors in young people of Mauritius.
Methods: This cross-sectional study comprised 202 participants aged between 14 to 29 years. The Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS) and the Adolescent Sleep Hygiene Scale (ASHS) were used to measure sleep quality, daytime sleepiness, and sleep hygiene respectively. Chi-squared tests were conducted to evaluate relationships between the collected variables. Multivariate logistic regression was used to identify associated factors with poor sleep quality.
Results: The mean global PSQI was 4.81 (95%CI: 4.4, 5.22). Prevalence of poor sleep quality (global PSQI score > 5) was 30.7%. The male gender reported better sleep (p=0.008). Sleep quality was significantly associated with longer sleep duration (p<0.0001), pre-bedtime relaxing activities (p=0.01), and daytime physical exercise (p=0.001). In contrast, alcohol consumption after 18:00 (p<0.0001), tobacco smoking after 18:00 (p<0.0001), pre-bedtime awakening activities (p=0.001), and poor sleep environment (p<0.0001) negatively influenced sleep quality. Multivariate logistic regression confirmed that female gender and sleep environment factors were associated with higher likelihood of poor sleep quality, while participants with longer duration of sleep (>7 hours), cognitive/emotional and sleep stability factors were found to be less likely to have poor sleep quality.
Conclusion: This study showed that the prevalence of poor sleep in young people in Mauritius was 30.7%. Female gender and sleep environment factors were main contributory factors. These initial results can guide further research on sleep quality
Collapse
|
3
|
Liu Y, Li H, Li G, Kang Y, Shi J, Kong T, Yang X, Xu J, Li C, Su KP, Wang F. Active smoking, sleep quality and cerebrospinal fluid biomarkers of neuroinflammation. Brain Behav Immun 2020; 89:623-627. [PMID: 32717405 DOI: 10.1016/j.bbi.2020.07.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 07/09/2020] [Accepted: 07/16/2020] [Indexed: 11/30/2022] Open
Abstract
BACKGROUNDS Cigarette smoking has been shown to be associated with sleep disorders and the related neuropathogenesis including neuroinflammation. Previous studies showed that pro- and anti-inflammatory cytokines are physiologically important in maintaining circadian function. In addition, sleep deprivation leads to immune dysregulations. However, no study has been published yet by using cerebrospinal fluid (CSF) biomarkers of neuroinflammation to investigate the relationship between active cigarette smoking and sleep disorders. METHODS CSF tissues from subjects of 191 male subjects (non-smokers n = 104; active smokers n = 87) receiving local anesthesia before surgery for anterior cruciate ligament injuries were obtained after the assessment of clinical information and Pittsburgh Sleep Quality Index (PSQI). The levels of tumor necrosis factor alpha (TNFα), Interleukin (IL) 1 beta (IL1β), IL2, IL4, IL6 and IL10 were measured using radioimmunoassay and ELISA. RESULTS PSQI scores were significantly higher in active smokers than that in non-smokers (p < 0.001, Cohen's d = 0.63). Significantly higher levels of CSF TNFα were found in active smokers compared to non-smokers (28 ± 1.97 vs. 22.97 ± 2.48, p < 0.05, Cohen's d = 2.23). There was a positive correlation between CSF IL1β levels and PSQI scores in non-smokers (r = 0.31, p = 0.01, adjustment R-Squared = 0.11). DISCUSSION This is the first study to reveal the association between higher CSF TNFα levels and poorer sleep quality in active smoking. In addition, CSF IL1β levels might be a potential biomarker in central nervous system for circadian dysregulation.
Collapse
Affiliation(s)
- Yanlong Liu
- School of Mental Health, Wenzhou Medical University, Wenzhou 325035, China; The Affiliated Kangning Hospital, Wenzhou Medical University, Wenzhou 325035, China
| | - Hui Li
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing 100871, China; The Second Affiliated Hospital, Xinjiang Medical University, Urumqi 830063, China; Psychosomatic Medicine Research Division, Inner Mongolia Medical University, Huhhot 010110, China
| | - Guohua Li
- The Second Affiliated Hospital, Xinjiang Medical University, Urumqi 830063, China
| | - Yimin Kang
- Psychosomatic Medicine Research Division, Inner Mongolia Medical University, Huhhot 010110, China
| | - Jianping Shi
- The Second Affiliated Hospital, Xinjiang Medical University, Urumqi 830063, China
| | - Tiantian Kong
- The Second Affiliated Hospital, Xinjiang Medical University, Urumqi 830063, China
| | - Xiaoyu Yang
- Beijing Jishuitan Hospital, Beijing 100035, China
| | - Jinzhong Xu
- The Affiliated Wenling Hospital of Wenzhou Medical University, Wenling 317500, China
| | - Cunbao Li
- Psychosomatic Medicine Research Division, Inner Mongolia Medical University, Huhhot 010110, China
| | - Kuan-Pin Su
- Department of Psychiatry & Mind-Body Interface Laboratory (MBI-Lab), China Medical University Hospital, Taichung, Taiwan; College of Medicine, China Medical University, Taichung, Taiwan; An-Nan Hospital, China Medical University, Tainan, Taiwan.
| | - Fan Wang
- Beijing Hui-Long-Guan Hospital, Peking University, Beijing 100096, China; The Second Affiliated Hospital, Xinjiang Medical University, Urumqi 830063, China.
| |
Collapse
|
4
|
Gillman AG, Rebec GV, Pecoraro NC, Kosobud AEK. Circadian entrainment by food and drugs of abuse. Behav Processes 2019; 165:23-28. [PMID: 31132444 DOI: 10.1016/j.beproc.2019.05.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 02/07/2023]
Abstract
Circadian rhythms organize behavior and physiological processes to be appropriate to the predictable cycle of daily events. These rhythms are entrained by stimuli that provide time of day cues (zeitgebers), such as light, which regulates the sleep-wake cycle and associated rhythms. But other events, including meals, social cues, and bouts of locomotor activity, can act as zeitgebers. Recent evidence shows that most organs and tissues contain cells that are capable of some degree of independent circadian cycling, suggesting the circadian system is broadly and diffusely distributed. Within laboratory studies of behavior, circadian rhythms tend to be treated as a complication to be minimized, but they offer a useful model of predictable shifts in behavioral tendencies. In the present review, we summarize the evidence that formed the basis for a hypothesis that drugs of abuse can entrain circadian rhythms and describe the outcome of a series of experiments designed to test that hypothesis. We propose that such drug-entrained rhythms may contribute to demonstrated daily variations in drug metabolism, tolerance, and sensitivity to drug reward. Of particular importance, these rhythms may be evoked by a single episode of drug taking, strengthen with repeated episodes, and re-emerge after long periods of abstinence, thereby contributing to drug abuse, addiction, and relapse.
Collapse
Affiliation(s)
- Andrea G Gillman
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - George V Rebec
- Program in Neuroscience, Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States
| | - Norman C Pecoraro
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States
| | - Ann E K Kosobud
- Dept. of Neurology, IU School of Medicine, 362 W 15th St, GH 4600, Indianapolis, Indiana, 46202-2266, United States.
| |
Collapse
|
5
|
Lindberg D, Andres-Beck L, Jia YF, Kang S, Choi DS. Purinergic Signaling in Neuron-Astrocyte Interactions, Circadian Rhythms, and Alcohol Use Disorder. Front Physiol 2018; 9:9. [PMID: 29467662 PMCID: PMC5808134 DOI: 10.3389/fphys.2018.00009] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 01/05/2018] [Indexed: 12/17/2022] Open
Abstract
Alcohol use disorder (AUD) is a debilitating condition marked by cyclic patterns of craving, use, and withdrawal. These pathological behaviors are mediated by multiple neurotransmitter systems utilizing glutamate, GABA, dopamine, ATP, and adenosine. In particular, purines such as ATP and adenosine have been demonstrated to alter the phase and function of the circadian clock and are reciprocally regulated by the clock itself. Importantly, chronic ethanol intake has been demonstrated to disrupt the molecular circadian clock and is associated with altered circadian patterns of activity and sleep. Moreover, ethanol has been demonstrated to disrupt purinergic signaling, while dysfunction of the purinergic system has been implicated in conditions of drug abuse such as AUD. In this review, we summarize our current knowledge regarding circadian disruption by ethanol, focusing on the reciprocal relationship that exists between oscillatory neurotransmission and the molecular circadian clock. In particular, we offer detailed explanations and hypotheses regarding the concerted regulation of purinergic signaling and circadian oscillations by neurons and astrocytes, and review the diverse mechanisms by which purinergic dysfuction may contribute to circadian disruption or alcohol abuse. Finally, we describe the mechanisms by which ethanol may disrupt or hijack endogenous circadian rhythms to induce the maladaptive behavioral patterns associated with AUD.
Collapse
Affiliation(s)
- Daniel Lindberg
- Neurobiology of Disease, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Lindsey Andres-Beck
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Yun-Fang Jia
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Seungwoo Kang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Doo-Sup Choi
- Neurobiology of Disease, Mayo Clinic College of Medicine, Rochester, MN, United States.,Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN, United States.,Department of Psychiatry and Psychology, Mayo Clinic College of Medicine, Rochester, MN, United States
| |
Collapse
|
6
|
Abstract
Reward-related learning, including that associated with drugs of abuse, is largely mediated by the dopaminergic mesolimbic pathway. Mesolimbic neurophysiology and motivated behavior, in turn, are modulated by the circadian timing system which generates ∼24-h rhythms in cellular activity. Both drug taking and seeking and mesolimbic dopaminergic neurotransmission can vary widely over the day. Moreover, circadian clock genes are expressed in ventral tegmental area dopaminergic cells and in mesolimbic target regions where they can directly modulate reward-related neurophysiology and behavior. There also exists a reciprocal influence between drug taking and circadian timing as the administration of drugs of abuse can alter behavioral rhythms and circadian clock gene expression in mesocorticolimbic structures. These interactions suggest that manipulations of the circadian timing system may have some utility in the treatment of substance abuse disorders. Here, the literature on bidirectional interactions between the circadian timing system and drug taking is briefly reviewed, and potential chronotherapeutic considerations for the treatment of addiction are discussed.
Collapse
|
7
|
Parekh PK, Ozburn AR, McClung CA. Circadian clock genes: effects on dopamine, reward and addiction. Alcohol 2015; 49:341-9. [PMID: 25641765 DOI: 10.1016/j.alcohol.2014.09.034] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 12/17/2022]
Abstract
Addiction is a widespread public health issue with social and economic ramifications. Substance abuse disorders are often accompanied by disruptions in circadian rhythms including sleep/wake cycles, which can exacerbate symptoms of addiction and dependence. Additionally, genetic disturbance of circadian molecular mechanisms can predispose some individuals to substance abuse disorders. In this review, we will discuss how circadian genes can regulate midbrain dopaminergic activity and subsequently, drug intake and reward. We will also suggest future directions for research on circadian genes and drugs of abuse.
Collapse
|
8
|
Webb IC, Lehman MN, Coolen LM. Diurnal and circadian regulation of reward-related neurophysiology and behavior. Physiol Behav 2015; 143:58-69. [PMID: 25708277 DOI: 10.1016/j.physbeh.2015.02.034] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/09/2015] [Accepted: 02/17/2015] [Indexed: 12/16/2022]
Abstract
Here, we review work over the past two decades that has indicated drug reward is modulated by the circadian system that generates daily (i.e., 24h) rhythms in physiology and behavior. Specifically, drug-self administration, psychomotor stimulant-induced conditioned place preference, and locomotor sensitization vary widely across the day in various species. These drug-related behavioral rhythms are associated with rhythmic neural activity and dopaminergic signaling in the mesocorticolimbic pathways, with a tendency toward increased activity during the species typical wake period. While the mechanisms responsible for such cellular rhythmicity remain to be fully identified, circadian clock genes are expressed in these brain areas and can function locally to modulate both dopaminergic neurotransmission and drug-associated behavior. In addition, neural and endocrine inputs to these brain areas contribute to cellular and reward-related behavioral rhythms, with the medial prefrontal cortex playing a pivotal role. Acute or chronic administration of drugs of abuse can also alter clock gene expression in reward-related brain regions. Emerging evidence suggests that drug craving in humans is under a diurnal regulation and that drug reward may be influenced by clock gene polymorphisms. These latter findings, in particular, indicate that the development of therapeutic strategies to modulate the circadian influence on drug reward may prove beneficial in the treatment of substance abuse disorders.
Collapse
Affiliation(s)
- Ian C Webb
- Dept. of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA.
| | - Michael N Lehman
- Dept. of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Lique M Coolen
- Dept. of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA; Dept. of Physiology & Biophysics, University of Mississippi Medical Center, Jackson, MS, USA
| |
Collapse
|
9
|
Gillman AG, Leffel JK, Kosobud AEK, Timberlake W. Behavioral characteristics and pharmacological manipulations of a nicotine-entrainable circadian oscillator. Chronobiol Int 2013; 30:855-69. [PMID: 23697901 DOI: 10.3109/07420528.2013.782314] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Chronic daily administration of nicotine and other drugs of abuse has been found to entrain pre- and post-drug circadian locomotor activity episodes that oscillate on a 24-h schedule and persist for several days after administration ceases. This drug-entrainable oscillator system could conceivably lead to circadian rhythms of drug seeking and drug use in human drug addicts. The present study (1) characterizes the ability of daily nicotine administration to entrain circadian wheel-running activity episodes in rats across a range of doses, lighting schedules, and food access; and (2) tests whether pre- and post-nicotine episodes can be altered through pharmacological manipulations. Adult female rats were housed in wheel boxes for 35-60 d, and both wheel-running and feeding-related behaviors were measured continuously. Following acclimation, nicotine or saline was administered for 16-24 d, and the rats were left undisturbed for several test days to observe the persistence of nicotine-entrained activity. The results showed that nicotine dose-dependently entrains wheel-running activity, and the highest dose of 1.0 mg/kg produces robust pre- and post-nicotine circadian activity episodes under constant, fixed, and variable light/dark schedules. In the pharmacological manipulation experiment, nicotine-entrained rats were administered one of seven pharmacological treatments (varenicline, mecamylamine, acamprosate, topiramate, naltrexone, SB-334867, or bupropion) in place of the nicotine injection for 2 d, and the rats were not disturbed for four subsequent days. Most of the treatment drugs significantly reduced post-nicotine activity episodes, but only three treatments affected pre-nicotine episodes: the μ- and κ-opioid receptor antagonist naltrexone, the orexin-1 receptor antagonist SB-334867, and the AMPA (2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid)/kainate antagonist topiramate. These results show that chronic daily nicotine administration is a robust zeitgeber that dose-dependently entrains a nonphotic oscillator system that includes opioid, orexin, and glutamate pathways.
Collapse
Affiliation(s)
- Andrea G Gillman
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania 15219-3143, USA.
| | | | | | | |
Collapse
|
10
|
Abstract
INTRODUCTION The ability of nicotine, the primary psychoactive substance in tobacco smoke, to regulate appetite and body weight is one of the factors cited by smokers that prevents them from quitting and is the primary reason for smoking initiation in teenage girls. The regulation of feeding and metabolism by nicotine is complex, and recent studies have begun to identify nicotinic acetylcholine receptor (nAChR) subtypes and circuits or cell types involved in this regulation. DISCUSSION We will briefly describe the primary anatomical and functional features of the input, output, and central integration structures of the neuroendocrine systems that regulate energy homeostasis. Then, we will describe the nAChR subtypes expressed in these structures in mammals to identify the possible molecular targets for nicotine. Finally, we will review the effects of nicotine and its withdrawal on feeding and energy metabolism and attribute them to potential central and peripheral cellular targets.
Collapse
Affiliation(s)
- Michele Zoli
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125, Modena, Italy.
| | | |
Collapse
|
11
|
The cholinergic system, circadian rhythmicity, and time memory. Behav Brain Res 2011; 221:466-80. [DOI: 10.1016/j.bbr.2010.11.039] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 11/19/2010] [Accepted: 11/22/2010] [Indexed: 01/23/2023]
|
12
|
Gillman AG, Leffel JK, Kosobud AEK, Timberlake W. Fentanyl, but not haloperidol, entrains persisting circadian activity episodes when administered at 24- and 31-h intervals. Behav Brain Res 2009; 205:102-14. [PMID: 19595707 PMCID: PMC2755526 DOI: 10.1016/j.bbr.2009.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 06/30/2009] [Accepted: 07/02/2009] [Indexed: 02/01/2023]
Abstract
Administration of several drugs of abuse on a 24-h schedule has been shown to entrain both pre-drug (anticipatory) and post-drug (evoked) circadian activity episodes that persist for several days when the drug is withheld. The present study tested the entrainment effects of fentanyl, an opioid agonist with a noted abuse liability, and haloperidol, an anti-psychotic dopamine antagonist without apparent abuse liability. Adult female Sprague-Dawley rats housed under constant light in cages with attached running wheels received repeated low, medium, or high doses of either fentanyl or haloperidol on a 24-h administration schedule followed by a 31-h schedule (Experiment 1) or solely on a 31-h schedule (Experiment 2). The results showed that all three doses of fentanyl entrained both pre-drug and post-drug episodes of wheel running when administered every 24h, and the combined pre- and post-fentanyl activity episodes persisted for at least 3 days when the drug was withheld during test days. On the 31-h schedule, fentanyl produced an "ensuing" activity episode approximately 24h post-administration, but failed to produce an anticipatory episode 29-31h post-administration. In contrast, haloperidol injections failed to produce both pre-drug episodes on the 24-h schedule and circadian ensuing episodes on the 31-h schedule, and post-haloperidol suppression of activity appeared to mask the free-running activity rhythm. Taken together, these results provide additional evidence that drugs of abuse share a common ability to entrain circadian activity episodes.
Collapse
Affiliation(s)
- Andrea G Gillman
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, United States.
| | | | | | | |
Collapse
|
13
|
Webb IC, Baltazar RM, Lehman MN, Coolen LM. Bidirectional interactions between the circadian and reward systems: is restricted food access a unique zeitgeber? Eur J Neurosci 2009; 30:1739-48. [PMID: 19878278 DOI: 10.1111/j.1460-9568.2009.06966.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Reward is mediated by a distributed series of midbrain and basal forebrain structures collectively referred to as the brain reward system. Recent evidence indicates that an additional regulatory system, the circadian system, can modulate reward-related learning. Diurnal or circadian changes in drug self-administration, responsiveness to drugs of abuse and reward to natural stimuli have been reported. These variations are associated with daily rhythms in mesolimbic electrical activity, dopamine synthesis and metabolism, and local clock gene oscillations. Conversely, the presentation of rewards appears capable of influencing circadian timing. Rodents can anticipate a daily mealtime by the entrainment of a series of oscillators that are anatomically distinct from the suprachiasmatic nucleus. Other work has indicated that restricted access to non-nutritive reinforcers (e.g. drugs of abuse, sex) or to palatable food in the absence of an energy deficit is capable of inducing relatively weak anticipatory activity, suggesting that reward alone is sufficient to induce anticipation. Recent attempts to elucidate the neural correlates of anticipation have revealed that both restricted feeding and restricted palatable food access can entrain clock gene expression in many reward-related corticolimbic structures. By contrast, restricted feeding alone can induce or entrain clock gene expression in hypothalamic nuclei involved in energy homeostasis. Thus, under ad libitum feeding conditions, the weak anticipatory activity induced by restricted reward presentation may result from the entrainment of reward-associated corticolimbic structures. The additional induction or entrainment of oscillators in hypothalamic regulatory areas may contribute to the more robust anticipatory activity associated with restricted feeding schedules.
Collapse
Affiliation(s)
- Ian C Webb
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | | | | | | |
Collapse
|
14
|
Abstract
The need to discover resources that are available under specific environmental constraints represents a fundamental environmental pressure on the evolution of behavior. Time-place discrimination refers to the ability to secure resources when they are available under specific temporal and spatial contingencies. This article reviews a number of examples of time-place discrimination. The review highlights theoretical and conceptual issues that are needed to behaviorally identify the mechanisms responsible for time-place performance. Next, limitations on time-place performance that may be imposed by a circadian system are described. Finally, a number of lines of research that broaden these limitations are discussed. These lines of research include studies that suggest that (i) a broad range of long intervals (outside the limited range of circadian entrainment) are timed, (ii) at least some long intervals (16-21 h) are timed with an endogenous self-sustaining oscillator, (iii) short intervals (in the range of 1-3 min) are timed with an endogenous self-sustaining oscillator, and (iv) memory for specific unique events (including when and where they occurred) is based on a circadian representation of time. It is concluded that a unified theory of timing that can retain the times of occurrence of individual events is needed. The time of occurrence of an event may be encoded not only with respect to a circadian oscillator but also with respect to other oscillators in the long-interval and short-interval ranges.
Collapse
Affiliation(s)
- Jonathon D Crystal
- Department of Psychology, University of Georgia, Athens, GA 30602-3013, USA.
| |
Collapse
|
15
|
Current world literature. Ageing: biology and nutrition. Curr Opin Clin Nutr Metab Care 2009; 12:95-100. [PMID: 19057195 DOI: 10.1097/mco.0b013e32831fd97a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|