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
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)
Review
Cell Biology
Raymond E. A. Sanchez, Franck Kalume, Horacio O. de la Iglesia
Summary: Nearly all mammals have robust daily rhythms called circadian rhythms, which are controlled by a master clock in the hypothalamus and affect various biological processes. This review summarizes the current understanding of circadian regulation of sleep, including neural circuitry, molecular mechanisms, and developmental regulation.
SEMINARS IN CELL & DEVELOPMENTAL BIOLOGY
(2022)
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
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.
Review
Neurosciences
Mariana Astiz, Lina Maria Delgado-Garcia, Laura Lopez-Mascaraque
Summary: Astrocytes have gained importance in building brain circuits and regulating complex behavior alongside neurons. The circadian system synchronizes physiological processes in mammals such as sleep-wake cycle and cognition. Recent breakthrough discoveries have implicated astrocytes as essential time-keepers in addition to neurons in the suprachiasmatic nucleus.
Article
Neurosciences
Vendula Luzna, Pavel Houdek, Karolina Liska, Alena Sumova
Summary: During fetal development, maternal signaling can impact the developing clock in the suprachiasmatic nuclei. Disruption of maternal signaling due to disturbances in the light/dark cycle can lead to changes in gene expression profiles in the fetal SCN. The fetal SCN is highly sensitive to various changes in maternal signaling related to environmental disturbances, showing gene-specific responses.
FRONTIERS IN NEUROSCIENCE
(2021)
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
Behavioral Sciences
Kayla E. Rohr, Adam Telega, Alexandra Savaglio, Jennifer A. Evans
Summary: Arginine vasopressin (AVP) is a neurohormone that affects cellular physiology through both endocrine and synaptic signaling. Circadian rhythms and other biological processes are regulated by the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Loss of AVP signaling has been found to alter circadian behavior, increase water consumption, and accelerate recovery from simulated jetlag. Additionally, it affects the period, imprecision, and plasticity of behavioral rhythms under constant darkness, and its impact on circadian period is influenced by sex. Examining SCN function directly, it has been shown that loss of AVP signaling modulates the period, precision, and phase relationships of SCN neurons in both sexes, suggesting sex differences in downstream targets of the SCN.
HORMONES AND BEHAVIOR
(2021)
Review
Cell Biology
Victoria M. Alvord, Elizabeth J. Kantra, Julie S. Pendergast
Summary: Circadian rhythms are 24-hour cycles of behavior and physiology generated by molecular clocks in various tissues. The suprachiasmatic nucleus (SCN) serves as the main circadian clock in mammals, receiving light information and coordinating tissue clocks. Estrogens play a role in regulating biological processes and behavior by interacting with circadian genes. This review focuses on the interplay between estrogens and the circadian system in female rodents, summarizing current understanding of their effects.
SEMINARS IN CELL & DEVELOPMENTAL BIOLOGY
(2022)
Article
Neurosciences
Floriana Mogavero, Kitty Zwieten, Jan K. Buitelaar, Jeffrey C. Glennon, Marloes J. A. G. Henckens
Summary: The study found that aggressive BALB/cJ mice showed deviations in various components related to circadian rhythm and hormone levels, including a shorter free-running period in constant darkness, reduced variability in state corticosterone levels, lower testosterone levels, and alterations in the expression of specific proteins in the suprachiasmatic nucleus.
EUROPEAN JOURNAL OF NEUROSCIENCE
(2022)
Review
Neurosciences
Daisuke Ono
Summary: Circadian rhythms are 24-hour oscillations in physiology and behavior, regulated by the suprachiasmatic nucleus (SCN) as the central circadian clock. Studies have shown that circadian oscillations can still occur in mice lacking certain clock genes, suggesting the presence of alternative oscillatory mechanisms. The neuronal circuits responsible for regulating sleep and wakefulness from the SCN have not been fully identified.
NEUROSCIENCE RESEARCH
(2022)
Article
Neurosciences
Hana Mikova, Viktor Kuchtiak, Irena Svobodova, Veronika Spisska, Dominika Pacesova, Ales Balik, Zdenka Bendova
Summary: The study evaluated the circadian rhythmicity of AMPA receptor GluA2 subunit in the SCN and other brain structures in Wistar rats, revealing differences in expression patterns and correlations in different brain regions.
MOLECULAR NEUROBIOLOGY
(2021)
Review
Biochemistry & Molecular Biology
Daisuke Ono, Ken-ichi Honma, Sato Honma
Summary: The central circadian clock in the mammalian suprachiasmatic nucleus (SCN) is regulated by the inhibitory neurotransmitter gamma-amino butyric acid (GABA), which influences circadian rhythms through intracellular Cl- concentration. The excitatory and inhibitory effects of GABA in the SCN are influenced by factors such as day-length, time, and region within the SCN. GABA mediates oscillatory coupling of circadian rhythms and refines circadian output rhythms, suggesting a downstream role in regulating the physiological and behavioral temporal order.
JOURNAL OF NEUROCHEMISTRY
(2021)
Article
Neurosciences
Dominika Pacesova, Veronika Spisska, Jiri Novotny, Zdenka Bendova
Summary: The study found that early-life morphine exposure has significant effects on the circadian clock and liver of rats, especially those born to control mothers but cross-fostered by morphine-exposed dams. These animals exhibited the highest mesor and amplitude in the rhythm of Per2 and Nr1d1 gene expression in the suprachiasmatic nuclei (SCN), as well as arrhythmicity in AA-NAT activity in the pineal gland. Five specific genes in the liver showed significant differences in expression, indicating the impact of cross-fostering on gene expression profiles.
BRAIN RESEARCH BULLETIN
(2021)
Article
Neurosciences
Yang He, Jun Tang, Meng Zhang, Junjie Ying, Dezhi Mu
Summary: This study investigated the protective effects and mechanisms of human placenta derived mesenchymal stem cells (hPMSCs) transplantation in a rat model of hypoxic-ischemic encephalopathy (HIE). The results showed that hPMSCs transplantation reduced apoptosis and improved long-term neurological prognosis. Furthermore, the downregulation of Sema 3A/NRP-1 expression and activation of the PI3K/Akt/mTOR signaling pathway played a key role in the protective effects of hPMSCs.
Article
Neurosciences
Emily L. Isenstein, Edward G. Freedman, Jiayi Xu, Ian A. DeAndrea-Lazarus, John J. Foxe
Summary: This study evaluated electrophysiological discrimination of parametric somatosensory stimuli in healthy young adults to understand how the brain processes the duration of tactile information. The results showed that participants did not electrophysiologically discriminate between 100 and 115 ms, but they exhibited distinct electrophysiological responses when the deviant stimuli were 130, 145, and 160 ms. These findings contribute to a better understanding of tactile sensitivity in different clinical conditions.
Article
Neurosciences
Juliana R. Souza, Ludmila Lima-Silveira, Daniela Accorsi-Mendonca, Benedito H. Machado
Summary: This study demonstrates that A2A receptors play a crucial role in modulating synaptic transmission in the NTS neurons and are required for the enhancement of glutamatergic transmission observed under short-term sustained hypoxia conditions.
Article
Neurosciences
Miki Hashizume, Rina Ito, Rie Suge, Yasushi Hojo, Gen Murakami, Takayuki Murakoshi
Summary: The basolateral amygdaloid complex (BLA) is closely involved in the formation of emotional memories, including both aversive memory and contextual fear memory. Acute sleep deprivation (SD) disrupts the acquisition of tone-associated fear memory in juvenile rats, but has no significant effect on contextual fear memory. Slow network oscillation in the amygdala contributes to the formation of amygdala-dependent fear memory in relation to sleep.
Article
Neurosciences
Qunxian Wang, Shipeng Guo, Dongjie Hu, Xiangjun Dong, Zijun Meng, Yanshuang Jiang, Zijuan Feng, Weihui Zhou, Weihong Song
Summary: GSDME plays a crucial role in the pathogenesis of Alzheimer's disease by regulating the switch from apoptosis to pyroptosis and participating in neuroinflammatory response. Knockdown of GSDME has been shown to improve cognitive impairments, indicating that GSDME could be a therapeutic target for Alzheimer's disease.
