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
Multidisciplinary Sciences
Natthapong Sueviriyapan, Daniel Granados-Fuentes, Tatiana Simon, Erik D. Herzog, Michael A. Henson
Summary: In the SCN, different types of GABA(A) receptors have been found to regulate circadian rhythms, with blocking GABA signaling modestly increasing synchrony and increasing the relative density of gamma over delta subunits significantly increasing synchrony.
JOURNAL OF THE ROYAL SOCIETY INTERFACE
(2021)
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
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
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
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
Neurosciences
Masahiro Matsuo, Kazuyuki Seo, Naoki Mizuguchi, Fumiyoshi Yamazaki, Shoichi Urabe, Naoto Yamada, Masao Doi, Keiko Tominaga, Hitoshi Okamura
Summary: The alpha 2 delta 3 protein plays a crucial role in synchronized cellular oscillations in the suprachiasmatic nucleus (SCN) and contributes to enhancing the sustainability of circadian rhythms in behavior. Mice lacking alpha 2 delta 3 showed severely impaired circadian locomotor activity rhythms under constant light conditions but exhibited normal behavior under constant dark conditions.
Article
Neurosciences
Chelsea A. Vadnie, Kaitlyn A. Petersen, Lauren A. Eberhardt, Mariah A. Hildebrand, Allison J. Cerwensky, Hui Zhang, Jennifer N. Burns, Darius D. Becker-Krail, Lauren M. DePoy, Ryan W. Logan, Colleen A. McClung
Summary: Individuals with mood and anxiety disorders often experience disruptions in sleep and circadian rhythms. This study explores the potential mechanisms underlying these disturbances, focusing on the dysregulation of the suprachiasmatic nucleus (SCN) and its impact on depressive- and anxiety-like behavior in mice. The results suggest that the dampening of homecage activity rhythms, mediated by the SCN, is directly correlated with increased anxiety-like behavior.
FRONTIERS IN NEUROSCIENCE
(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)
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
Eui Min Jeong, Miri Kwon, Eunjoo Cho, Sang Hyuk Lee, Hyun Kim, Eun Young Kim, Jae Kyoung Kim
Summary: In metazoan organisms, circadian rhythms are regulated by pacemaker neurons organized in a master-slave hierarchy. This study reveals the heterogeneity in molecular clockworks between master pacemakers and slave oscillators, with higher PER synthesis and turnover, as well as lower CLK levels in the master pacemakers. The distinct molecular clockwork of the master pacemakers allows them to generate strong rhythms and adapt flexibly to environmental changes.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Ashleigh G. Wilcox, R. Sonia Bains, Debbie Williams, Elizabeth Joynson, Lucie Vizor, Peter L. Oliver, Elizabeth S. Maywood, Michael H. Hastings, Gareth Banks, Patrick M. Nolan
Summary: The study describes a mouse mutant with the central pacemaker SCN genetically ablated, leading to arrhythmicity in circadian rhythms and metabolic parameters, although the mutants could still anticipate food availability. Despite disruptions to SCN cell identity and circuitry, the mutants' activity levels were altered and other zeitgebers could not restore rhythmicity.
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)
Article
Multidisciplinary Sciences
Lidia Giantomasi, Joao F. Ribeiro, Olga Barca-Mayo, Mario Malerba, Ermanno Miele, Davide De Pietri Tonelli, Luca Berdondini
Summary: In mammals, the suprachiasmatic nucleus (SCN) is the master regulator of circadian rhythms, synchronizing clocks in the central nervous system and periphery. The mechanisms behind how these clocks are effectively synchronized are not well understood. This study investigated the involvement of astrocytes and neuronal paracrine factors in clock synchronization. The findings revealed that both pathways play a role, with astrocytes acting as active cells in distributing long-range signals to synchronize brain clocks.
SCIENTIFIC REPORTS
(2023)
Article
Biology
Iain Hunter, Raz Leib
Summary: Natural movement is related to health, but it is difficult to measure. Existing methods cannot capture the full range of natural movement. Comparing movement across different species helps identify common biomechanical and computational principles. Developing a system to quantify movement in freely moving animals in natural environments and relating it to life quality is crucial. This study proposes a theoretical framework based on movement ability and validates it in Drosophila.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Andy Gardner
Summary: Fisher's geometric model is a useful tool for predicting key properties of Darwinian adaptation, and here it is applied to predict differences between the evolution of altruistic versus nonsocial phenotypes. The results suggest that the effect size maximizing probability of fixation is smaller in the context of altruism and larger in the context of nonsocial phenotypes, leading to lower overall probability of fixation for altruism and higher overall probability of fixation for nonsocial phenotypes.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Thomas F. Pak, Joe Pitt-Francis, Ruth E. Baker
Summary: Cell competition is a process where cells interact in multicellular organisms to determine a winner or loser status, with loser cells being eliminated through programmed cell death. The winner cells then populate the tissue. The outcome of cell competition is context-dependent, as the same cell type can win or lose depending on the competing cell type. This paper proposes a mathematical framework to study the emergence of winner or loser status, highlighting the role of active cell death and identifying the factors that drive cell competition in a cell-based modeling context.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Haruto Tomizuka, Yuuya Tachiki
Summary: Batesian mimicry is a strategy in which palatable prey species resemble unpalatable prey species to avoid predation. The evolution of this mimicry plays a crucial role in protecting the unpalatable species from extinction.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Jason W. Olejarz, Martin A. Nowak
Summary: Gene drive technology shows potential for population control, but its release may have unpredictable consequences. The study suggests that the failure of suppression is a natural outcome, and there are complex dynamics among wild populations.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Hamid Ravaee, Mohammad Hossein Manshaei, Mehran Safayani, Javad Salimi Sartakhti
Summary: Gene expression analysis is valuable for cancer classification and phenotype identification. IP3G, based on Generative Adversarial Networks, enhances gene expression data and discovers phenotypes in an unsupervised manner. By converting gene expression profiles into images and utilizing IP3G, new phenotype profiles can be generated, improving classification accuracy.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Beatrix Rahnsch, Leila Taghizadeh
Summary: This study forecasts the evolution of the COVID-19 pandemic in Germany using a network-based inference method and compares it with other approaches. The results show that the network-inference based approach outperforms other methods in short-to mid-term predictions, even with limited information about the new disease. Furthermore, predictions based on the estimation of the reproduction number in Germany can yield more reliable results with increasing data availability, but still cannot surpass the network-inference based algorithm.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Rongsheng Huang, Qiaojun Situ, Jinzhi Lei
Summary: Maintaining tissue homeostasis requires appropriate regulation of stem cell differentiation. Random inheritance of epigenetic states plays a pivotal role in stem cell differentiation. This computational model provides valuable insights into the intricate mechanism governing stem cell differentiation and cell reprogramming, offering a promising path for enhancing the field of regenerative medicine.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Patrick Vincent N. Lubenia, Eduardo R. Mendoza, Angelyn R. Lao
Summary: This study compares insulin signaling in healthy and type 2 diabetes states using reaction network analysis. The results show similarities and differences between the two conditions, providing insights into the mechanisms of insulin resistance, including the involvement of other complexes, less restrictive interplay between species, and loss of concentration robustness in GLUT4.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Nuverah Mohsin, Heiko Enderling, Renee Brady-Nicholls, Mohammad U. Zahid
Summary: Mathematical modeling is crucial in understanding radiobiology and designing treatment approaches in radiotherapy for cancer. This study compares three tumor volume dynamics models and analyzes the implications of model selection. A new metric, the point of maximum reduction of tumor volume (MRV), is introduced to quantify the impact of radiotherapy. The results emphasize the importance of caution in selecting models of response to radiotherapy due to the artifacts imposed by each model.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
Article
Biology
Armindo Salvador
Summary: Michael Savageau's Biochemical Systems Analysis papers have had a significant impact on Systems Biology, generating core concepts and tools. This article provides a brief summary of these papers and discusses the most relevant developments in Biochemical Systems Theory since their publication.
JOURNAL OF THEORETICAL BIOLOGY
(2024)
