Review
Biochemistry & Molecular Biology
Evrim Yildirim, Rachel Curtis, Dae-Sung Hwangbo
Summary: Biological clocks are essential mechanisms that synchronize physiological and behavioral processes with external cues to ensure organisms' fitness and survival. While the central clock in the brain drives daily activity rhythms, peripheral tissues have their own clock systems generating metabolic and physiological rhythms. The fruit fly Drosophila melanogaster has been a widely studied model organism for investigating the mechanism and functions of circadian clocks.
Article
Biology
Peter S. Johnstone, Maite Ogueta, Olga Akay, Inan Top, Sheyum Syed, Ralf Stanewsky, Deniz Top
Summary: This study developed a new method, called Locally Activatable BioLuminescence (LABL), to directly measure the transcriptional oscillation of specific neuronal and peripheral clocks in intact Drosophila. The results showed that loss of the receptor for the circadian neurotransmitter PDF only disrupted locomotor activity but not all tissue-specific circadian clocks.
Review
Pharmacology & Pharmacy
Jingxuan Zhou, Jiechen Wang, Xiaozhao Zhang, Qingming Tang
Summary: Circadian clocks play a vital role in maintaining homeostasis and are closely related to cancer development. Chronotherapy for cancer treatment should leverage circadian rhythms for higher efficacy, and an individualized approach is recommended due to interpatient differences in circadian functions. Understanding the specific association between circadian clocks and cancers will pave the way for more effective clinical treatments.
FRONTIERS IN PHARMACOLOGY
(2021)
Review
Biochemistry & Molecular Biology
Amy R. Poe, Kyla D. Mace, Matthew S. Kayser
Summary: Research shows that while molecular circadian rhythms are present in early development, most behavioral rhythms, like sleep-wake cycles, only emerge later. The study focuses on the development of circadian clocks, outputs, and behaviors in various species, with a specific emphasis on Drosophila. Potential mechanisms for communication between central clocks and circadian output sites are explored, along with the evolutionary perspective on why behavioral rhythms emerge long after central clocks begin functioning.
Article
Neurosciences
Michael C. Tackenberg, Jacob J. Hughey, Douglas G. McMahon
Summary: The research shows that selective activation of VIPergic SCN neurons induces photoperiodic network plasticity in the SCN, underlying photoperiodic entrainment of behavior.
EUROPEAN JOURNAL OF NEUROSCIENCE
(2021)
Review
Biochemistry & Molecular Biology
Leonardo Vinicius Monteiro de Assis, Henrik Oster
Summary: The circadian clock plays a crucial role in maintaining systemic homeostasis by synchronizing with environmental challenges and biological processes. Communication between central and peripheral clocks is essential, and the modulation of metabolic organs by the circadian clock is a key aspect of its function. Recent studies on communication between peripheral tissues provide new insights into circadian organization.
CELLULAR AND MOLECULAR LIFE SCIENCES
(2021)
Article
Neurosciences
Nien-Du Yang, Rebecca L. Mellor, Tracey O. Hermanstyne, Jeanne M. Nerbonne
Summary: Neurons in the suprachiasmatic nucleus (SCN) generate circadian changes in action potential firing rates that regulate daily rhythms. Changes in subthreshold potassium conductance or sodium leak conductance may mediate these circadian changes. This study investigated the role of sodium leak currents in regulating firing rates in SCN neurons and found that they selectively regulate daytime firing rates through interaction with potassium currents. These findings demonstrate the importance of sodium leak channels in regulating the excitability of SCN neurons.
JOURNAL OF NEUROSCIENCE
(2023)
Review
Neurosciences
Javier Cavieres-Lepe, John Ewer
Summary: Circadian rhythms in animals are driven by intracellular transcriptional/translational feedback loops, and Ca2+ signaling plays a crucial role in regulating the molecular rhythms and behavior. There is evidence of reciprocal interaction between Ca2+ signaling and circadian clocks, with genes encoding Ca2+ channels and binding proteins showing rhythmic expression and disruption affecting circadian function. Additionally, Ca2+ rhythms and signaling pathways modulate clock gene expression at transcriptional and post-translational levels, potentially impacting pharmacotherapy and clinical interventions.
FRONTIERS IN MOLECULAR NEUROSCIENCE
(2021)
Article
Endocrinology & Metabolism
Gabriella M. Marino, Deanna M. Arble
Summary: Sleep and circadian disruption are linked to a higher risk of metabolic disease. Researchers propose that targeting groups of cells with functional relationships can provide a better understanding of the consequences of sleep and circadian disruption, especially for metabolic outcomes that involve multiple sites of action.
FRONTIERS IN ENDOCRINOLOGY
(2023)
Review
Physiology
Maria Luisa Jabbur, Carl Hirschie Johnson
Summary: This paper reviews the literature on the ecology and evolution of circadian clocks, with a special focus on cyanobacteria as model organisms. It discusses the role of circadian clocks in adaptive fitness and their potential response to climate change. The paper also explores the oldest known circadian clock and its evolution under early Earth conditions.
FRONTIERS IN PHYSIOLOGY
(2022)
Review
Cell Biology
Rona Aviram, Yaarit Adamovich, Gad Asher
Summary: Circadian clocks are present in most light-sensitive organisms, leading to circadian rhythmicity in various biological functions, including intracellular organelles. Although there have been studies on the rhythmicity of organelles, there still exist knowledge gaps, particularly in the understanding of molecular mechanisms and functional significance.
Review
Physiology
Yaarit Adamovich, Vaishnavi Dandavate, Gad Asher
Summary: This article reviews the interaction between the circadian clock and the oxygen-signalling pathway in mammals under normal and pathological conditions. Evidence suggests that the circadian clock can sense and regulate changes in oxygen levels through the HIF-1 signalling pathway, further influencing the rhythmicity of the clock itself.
Article
Biology
Mikolaj Mazur, Magdalena Markowska, Magdalena Chadzinska, Lukasz Pijanowski
Summary: This study provides a detailed analysis of the rhythmic expression of key components of the biological clock in common carp. The expression of clock genes, bmal genes, per genes, and cry genes in the brain, pituitary gland, and retina of carp was found to be the highest. The expression pattern of clock and bmal genes aligned with the lights off, while per genes showed a similar phasing with acrophase close to light onset. The expression of cry genes varied depending on the type of tissue and gene subtype.
CHRONOBIOLOGY INTERNATIONAL
(2023)
Review
Cardiac & Cardiovascular Systems
Nadim El Jamal, Ronan Lordan, Sarah L. Teegarden, Tilo Grosser, Garret FitzGerald
Summary: Cardiac physiology is regulated by autonomous molecular clocks and the suprachiasmatic nucleus, exhibiting diurnal rhythms. Disrupting molecular clocks can lead to heart failure, and the time of day can condition myocardial response to injury. Human studies support the involvement of molecular clocks and circadian rhythms in the pathogenesis of heart failure. Certain circadian rhythms are maintained in heart failure patients, which can guide optimal timing of therapy. Manipulation of circadian rhythms and molecular clocks show promise in the prevention and treatment of heart failure.
CIRCULATION RESEARCH
(2023)
Article
Biology
Meimei Liao, Xinwei Gao, Chen Chen, Qi Li, Qingchun Guo, He Huang, Erquan Zhang, Dapeng Ju
Summary: This study presents the first comprehensive map of suprachiasmatic nucleus (SCN) efferent connections and suggests a molecular logic underlying these projections. The findings indicate variations in efferent projections from different subtypes of SCN neurons and the development of a new barcoding system to study the molecular logic of neuronal circuits.
SCIENCE CHINA-LIFE SCIENCES
(2023)
Article
Biochemical Research Methods
Suihong Huang, Qingqing Lu, Ming Ho Choi, Xuebing Zhang, Jin Young Kim
Summary: This protocol combines a protective cutting method and real-time monitoring of circadian oscillations for studying the impact of brain damages on local circadian clocks and variations in nearby areas. Further functional analyses with in vivo systems can determine whether these variations are detrimental or beneficial to the brain.