Article
Multidisciplinary Sciences
Beatriz Bano-Otalora, Franck Martial, Court Harding, David A. Bechtold, Annette E. Allen, Timothy M. Brown, Mino D. C. Belle, Robert J. Lucas
Summary: The study reveals an impact of daytime light intensity on SCN physiology and the amplitude of circadian rhythms, with lower daytime irradiance leading to a marked reduction in the amplitude of spontaneous activity.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Deborah A. M. Joye, Kayla E. Rohr, Kimberlee Suenkens, Alissa Wuorinen, Thomas Inda, Madeline Arzbecker, Emma Mueller, Alec Huber, Harshida Pancholi, Murray G. Blackmore, Vania Carmona-Alcocer, Jennifer A. Evans
Summary: Daily and annual changes in light are processed by central clock circuits. The role of somatostatin (SST) in the response of the suprachiasmatic nucleus (SCN) to light has not been examined. Our study shows that SST signaling regulates daily rhythms in behavior and SCN function, with sex-specific effects. Lack of SST signaling increases circadian plasticity and eliminates sex differences in photic responses.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Takashi Maejima, Yusuke Tsuno, Shota Miyazaki, Yousuke Tsuneoka, Emi Hasegawa, Md Tarikul Islam, Ryosuke Enoki, Takahiro J. Nakamura, Michihiro Mieda
Summary: The study found that specific deletion of vesicular GABA transporter in AVP neurons led to significant impairment of circadian rhythm and disruption of GABA-mediated synaptic transmission in SCN neurons. While molecular circadian oscillations among SCN neurons did not significantly change, there were significant alterations in the phase relationships between molecular clocks and circadian behavioral activities.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Review
Biology
Ashley N. N. Starnes, Jeff R. R. Jones
Summary: In mammals, circadian rhythms are controlled by the suprachiasmatic nucleus (SCN), which synchronizes the brain and body to local time. However, the circuits linking the SCN to the external world and downstream targets are poorly understood. This review discusses the inputs to and outputs from the SCN, emphasizing the importance of understanding the circadian connectome for human health.
Article
Multidisciplinary Sciences
Qiang Liu, Benjamin J. Bell, Dong Won Kim, Sang Soo Lee, Mehmet F. Keles, Qili Liu, Ian D. Blum, Annette A. Wang, Elijah J. Blank, Jiali Xiong, Joseph L. Bedont, Anna J. Chang, Habon Issa, Jeremiah Y. Cohen, Seth Blackshaw, Mark N. Wu
Summary: This study reveals the role of a clock-output molecule in reducing arousal circuit excitability during the active phase, suggesting a multifaceted role for the circadian clock in regulating arousal.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Hester C. van Diepen, Robin A. Schoonderwoerd, Ashna Ramkisoensing, Jan A. M. Janse, Samer Hattar, Johanna H. Meijer
Summary: The study reveals the significant role of cone photoreceptors in regulating circadian rhythms, transmitting light information to the suprachiasmatic nuclei, and affecting their electrical activity levels.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Andrew P. Patton, Emma L. Morris, David McManus, Huan Wang, Yulong Li, Jason W. Chin, Michael H. Hastings
Summary: The hypothalamic suprachiasmatic nucleus (SCN) is the master mammalian circadian clock. GABA plays a role in circuit-level timekeeping of SCN neurons, despite the inhibitory effect of increased neuronal firing. The astrocytic clocks in SCN maintain the circadian clockwork by controlling GABAergic inhibition.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Biochemistry & Molecular Biology
Arthur H. Cheng, Samuel W. Fung, Sara Hegazi, Osama Hasan Mustafa Hasan Abdalla, Hai-Ying Mary Cheng
Summary: The hypothalamic suprachiasmatic nucleus (SCN) functions as the central circadian pacemaker, and the transcription factor Sox2 plays a crucial role in controlling the expression of circadian neuropeptides and transcription factors in the embryonic SCN. Sox2 deficiency leads to reduced survival of SCN neurons during the postnatal period, but does not affect progenitor cell proliferation or SCN specification.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Neurosciences
Anneke H. O. Olde Engberink, Pablo de Torres Gutierrez, Anna Chiosso, Ankita Das, Johanna H. Meijer, Stephan Michel
Summary: Aging impairs the function of the central circadian clock, resulting in reduced output signal and decline in rhythm strength. The reduced amplitude of the signal is caused by decreased synchrony among the SCN neurons. The study reveals an increased excitation/inhibition balance and altered Ca2+ homeostasis in SCN neurons of old mice, suggesting their contribution to the altered synchrony within the aged SCN network.
FRONTIERS IN NEUROSCIENCE
(2023)
Review
Biochemistry & Molecular Biology
Noboru Imai
Summary: Migraine, a type of primary headache, exhibits circadian and circannual rhythms in attack onset, which involve the hypothalamus and melatonin. The prophylactic effect of melatonin in migraines is still controversial. Meanwhile, calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating peptide (PACAP) play important roles in the pathophysiology and treatment of migraines by regulating circadian entrainment to light and could be potential therapeutic targets.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Physiology
Iwona Olejniczak, Benjamin Campbell, Yuan-Chen Tsai, Shiva K. Tyagarajan, Urs Albrecht, Jurgen A. Ripperger
Summary: The process of searching for food in mammals is well-organized and follows a decision-making process based on necessity. Scavenging is preferred during their active phase. Previous studies have identified various time-dependent regulatory processes originating from the suprachiasmatic nuclei (SCN), which convert external light information into synchronizing output signals. This study revisits the function of the SCN in influencing the timing of food searching in mice and finds that it is independent of light but modified by the palatability of the food source.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Neurosciences
Claudia Coomans, Dirk-Jan Saaltink, Tom Deboer, Mayke Tersteeg, Suzanne Lanooij, Anne Fleur Schneider, Aat Mulder, Jan van Minnen, Carolina Jost, Abraham J. Koster, Erno Vreugdenhil
Summary: The newly identified plasticity protein DCL is specifically expressed in the shell of the mouse suprachiasmatic nucleus and is involved in neuroplastic events that require rearrangements of the microtubule cytoskeleton for dynamic cell movement. DCL-positive astrocytes envelop AVP-expressing cells in the SCN, suggesting a role in astrocytic plasticity in regulating circadian rhythms and potentially influencing AVP biosynthesis.
Article
Neurosciences
Ryan Hamnett, Johanna E. Chesham, Elizabeth S. Maywood, Michael H. Hastings
Summary: Circadian rhythms in mammals are generated by cell-autonomous transcriptional/translational feedback loops, coordinated by the hypothalamic suprachiasmatic nucleus (SCN). Cells expressing VIP mediate retinal entrainment of the SCN, while deletion of Bmal1 severely disrupts circadian behavioral rhythms.
JOURNAL OF NEUROSCIENCE
(2021)
Article
Behavioral Sciences
Max de Leeuw, Sanne I. Verhoeve, Nic J. A. van der Wee, Albert M. van Hemert, Erno Vreugdenhil, Claudia P. Coomans
Summary: Circadian rhythms are closely related to depression, and disruption of circadian rhythms may contribute to the development of depression. A better understanding of the connection between disturbed circadian rhythms and the etiology of depression could lead to novel therapeutic and preventative strategies.
NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS
(2023)
Article
Biology
Beatriz Bano-Otalora, Matthew J. Moye, Timothy Brown, Robert J. Lucas, Casey O. Diekman, Mino D. C. Belle
Summary: The study revealed that SCN neurons in the diurnal rodent Rhabdomys pumilio are more excited during daytime hours, but their evoked activity includes a suppressive response not present in nocturnal rodents. By investigating the evoked electrical activity, researchers confirmed the key role of transient subthreshold A-type potassium channels in this response.
Article
Neurosciences
Lukasz Chrobok, Jagoda Stanislawa Jeczmien-Lazur, Kamil Pradel, Jasmin Daniela Klich, Monika Bubka, Michal Wojcik, Mariusz Kepczynski, Marian Henryk Lewandowski
Summary: The study reveals that biological clocks regulate the circadian rhythm of non-image forming visual structures through the orexinergic system. Orexins show higher levels at night and directly regulate responses to retinal input in the lateral geniculate nucleus. The orexinergic system plays a crucial role in circadian modulation of neurons processing ambient light levels in the brain.
JOURNAL OF PHYSIOLOGY-LONDON
(2021)
Article
Physiology
Lukasz Chrobok, Michal Wojcik, Jasmin Daniela Klich, Kamil Pradel, Marian Henryk Lewandowski, Hugh David Piggins
Summary: The study explored the phasic neuronal activity in the rodent NTS using multi-electrode array recordings ex vivo, revealing a characteristic phasic pattern displayed by a subset of neurons in the dorsomedial NTS. It found that mice exhibit higher phasic frequency and firing rate compared to rats, peaking at the middle of the night. Additionally, the phasic cells were shown to be sensitive to alpha(2) adrenergic receptors activation and responsive to electrical stimulation of the area postrema, potentially identifying them as downstream targets of the AP noradrenergic system.
FRONTIERS IN PHYSIOLOGY
(2021)
Article
Cell Biology
Mateusz Jez, Alicja Martyniak, Kalina Andrysiak, Olga Mucha, Krzysztof Szade, Alan Kania, Lukasz Chrobok, Katarzyna Palus-Chramiec, Anna M. Sanetra, Marian H. Lewandowski, Ewelina Pospiech, Jacek Stepniewski, Jozef Dulak
Summary: This study demonstrated for the first time the crucial role of HO-1 in the electrophysiology of human cardiomyocytes using CRISPR/Cas9 technology. While the lack of HO-1 did not affect the differentiation efficiency and metabolism of hiPSCs, it led to alterations in electrophysiological pathways in hiPSC-CMs, potentially impacting the functionality of cardiomyocytes.
Article
Biochemistry & Molecular Biology
Lukasz Chrobok, Jagoda Stanislawa Jeczmien-Lazur, Monika Bubka, Kamil Pradel, Aleksandra Klekocinska, Jasmin Daniela Klich, Amalia Ridla Rahim, Jihwan Myung, Mariusz Kepczynski, Marian Henryk Lewandowski
Summary: The study reveals a coordination between the orexin system and the rodent superior colliculus across the day-night cycle, with orexin input predominantly occurring nocturnally and the SC neurons responding to orexin A and exhibiting circadian expression of clock genes.
Article
Neurosciences
Lukasz Chrobok, Jasmin D. Klich, Jagoda S. Jeczmien-Lazur, Kamil Pradel, Katarzyna Palus-Chramiec, Anna M. Sanetra, Hugh D. Piggins, Marian H. Lewandowski
Summary: Recent research has shown that the dorsal vagal complex possesses strong circadian timekeeping capabilities, with specific areas showing robust clock properties. The dorsal motor nucleus of the vagus, as an executory part of this complex, plays a role in regulating gastric motility and energy homeostasis. This study found that neuronal activity in the DMV varies with time of day and diet, providing important insights into the daily control of vagal efferents and parasympathetic outflow.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Neurosciences
Lukasz Chrobok, Jasmin D. Klich, Anna M. Sanetra, Jagoda S. Jeczmien-Lazur, Kamil Pradel, Katarzyna Palus-Chramiec, Mariusz Kepczynski, Hugh D. Piggins, Marian H. Lewandowski
Summary: Short-term consumption of a high-fat diet increases daytime food intake and blunts daily rhythms in NTS neuronal discharge, while also decreasing responsiveness to metabolic neuropeptides and orexin immunoreactive fibres. These alterations occur without prominent body weight gain, suggesting that a high-fat diet initially reduces activity in the dorsal vagal complex to disinhibit mechanisms that suppress daytime feeding.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Biochemistry & Molecular Biology
Lukasz Chrobok, Sylwia Bajkacz, Jasmin Daniela Klich, Marian Henryk Lewandowski
Summary: Orexins are neuropeptides synthesised mainly in the brain lateral hypothalamic area, playing a vital role in feeding behaviour, regulation of the sleep-wake cycle and circadian rhythms. This study developed a LC-MS/MS method for quantitative bioanalysis of orexin in the rat vitreous body, showing potential implications on circadian regulation of vision with the first demonstration of daily rhythm of orexin synthesis by the retina.
Review
Medicine, Research & Experimental
Sandra Fawcett, Raida Al Kassas, Iain M. Dykes, Alun T. L. Hughes, Fawaz Ghali, Kehinde Ross
Summary: This review explores the intersection of mechanisms by which circadian and miRNA responses interact with each other in relation to wound repair in the skin, supporting the development of translational insights in circadian medicine.
Article
Neurosciences
Anna Magdalena Sanetra, Katarzyna Palus-Chramiec, Lukasz Chrobok, Marian Henryk Lewandowski
Summary: The dorsomedial hypothalamus (DMH) plays a crucial role in regulating feeding behavior and metabolism, particularly in relation to circadian rhythmicity and energy homeostasis. This study exposed rats to short-term high-fat diet (HFD) and found that it disrupted the firing frequency of DMH cells, leading to abnormal daytime feeding and potentially contributing to the development of obesity. Additionally, the study identified distinct anatomical and functional subpopulations of DMH neurons, providing insight into the complex electrophysiological characteristics of this brain structure.
EUROPEAN JOURNAL OF NEUROSCIENCE
(2022)
Article
Physiology
Kamil Pradel, Gniewosz Drwiega, Lukasz Chrobok, Tomasz Blasiak
Summary: The dopaminergic system is regulated by circadian rhythms, which affect animal motivation, responsiveness to rewards and punishment, exploratory behaviors, and motor performance. This regulation is likely achieved through changes in core clock genes, ion channels, neurotransmitter receptors, dopamine-synthesizing enzymes, and dopamine transporters.
FRONTIERS IN PHYSIOLOGY
(2022)
Editorial Material
Neurosciences
Alun Thomas Lloyd Hughes, Hrayr P. Attarian, Jun Hirayama
FRONTIERS IN NEUROSCIENCE
(2022)
Article
Physiology
Lukasz Chrobok, Jake Ahern, Hugh D. Piggins
Summary: This article evaluates how intrinsic circadian signals regulate the activity of the dorsal vagal complex (DVC) and proposes possible functions of DVC in circadian control of feeding behavior.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Neurosciences
Jagoda S. Jeczmien-Lazur, Anna M. Sanetra, Kamil Pradel, Gabriela Izowit, Lukasz Chrobok, Katarzyna Palus-Chramiec, Hugh D. Piggins, Marian H. Lewandowski
Summary: The intergeniculate leaflet and ventral lateral geniculate nucleus (IGL/VLG) play an important role in entraining the brain's circadian system to various cues. We investigated the sensitivity of IGL/VLG neurons to metabolism-related peptides and found that they responded to most of the substances tested, suggesting their involvement in the body's energy homeostasis.
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Article
Nutrition & Dietetics
Anna Magdalena Sanetra, Katarzyna Palus-Chramiec, Lukasz Chrobok, Jagoda Stanislawa Jeczmien-Lazur, Emilia Gawron, Jasmin Daniela Klich, Kamil Pradel, Marian Henryk Lewandowski
Summary: Obesity is a growing health problem and studying its developmental mechanism is crucial. This study found that a high-fat diet disrupts the circadian rhythmicity of the dorsomedial hypothalamus (DMH) in male rats, indicating its possible role in obesity development. Additionally, time-restricted feeding can prevent the disruptive effects of a high-fat diet on the DMH clock.
Article
Multidisciplinary Sciences
Timna Hitrec, Cheryl Petit, Emily Cryer, Charlotte Muir, Natalie Tal, Jean-Michel Fustin, Alun T. L. Hughes, Hugh D. Piggins
Summary: Timed daily access to a running-wheel synchronizes circadian rhythms and promotes stable rhythms in animals with impaired neuropeptide signaling. The transcriptome of the brain clock showed extensive dysregulation in these animals, but the molecular programs in the liver and lung were partially intact. Furthermore, exercise could correct behavioral abnormalities in circadian rhythms without causing large scale alterations in the brain clock.