We study synaptically coupled neuronal networks to identify the role of coupling delays in network synchronized behaviour. We consider a network of excitable, relaxation oscillator neurons where two distinct populations, one excitatory and one inhibitory, are coupled with time-delayed synapses. The excitatory population is uncoupled, while the inhibitory population is tightly coupled without time delay. A geometric singular perturbation analysis yields existence and stability conditions for periodic solutions where the excitatory cells are synchronized and different phase relationships between the excitatory and inhibitory populations can occur, along with formulae for the periods of such solutions. In particular, we show that if there are no delays in the coupling, oscillations where the excitatory population is synchronized cannot occur. Numerical simulations are conducted to supplement and validate the analytical results. The analysis helps to explain how coupling delays in either excitatory or inhibitory synapses contribute to producing synchronized rhythms. This article is part of the theme issue 'Nonlinear dynamics of delay systems'.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6661332 | PMC |
http://dx.doi.org/10.1098/rsta.2018.0129 | DOI Listing |
Nanomaterials (Basel)
January 2025
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Environmental changes, such as applied medication, nutrient depletion, and accumulation of metabolic residues, affect cell culture activity. The combination of these factors reflects on the local temperature distribution and local oxygen concentration towards the cell culture scaffold. However, determining the temporal variation of local temperature, independent of local oxygen concentration changes in biological specimens, remains a significant technological challenge.
View Article and Find Full Text PDFBMC Womens Health
January 2025
School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
Background: Prenatal maternal smoking, lower birthweight, and shorter breastfeeding duration have all been associated with an earlier age at menopause in daughters. We estimated the extent to which birthweight-for-gestational-age z-score and breastfeeding duration mediate the effect of prenatal maternal smoking on time to natural menopause in daughters.
Methods: Using pooled data from two prospective birth cohort studies - the 1970 British Cohort Study (n = 3,878) followed-up to age 46 years and the 1958 National Child Development Study (n = 4,822) followed-up to age 50 years - we perform mediation analysis with inverse odds weighting implemented in Cox proportional-hazards models.
Am J Emerg Med
January 2025
Departments of Emergency Medicine and Critical Care Medicine, Stanford Health Care, 900 Welch Road, Palo Alto, CA 94304, USA.
Background: Critically ill ED patients on life support may undergo transition to comfort care as decided by the surrogate decision maker. When several hours are needed for loved ones to arrive and say farewell before initiating comfort care ("delayed comfort care"), these patients require prolonged ED stays or costly intensive care unit (ICU) admissions.
Methods: A novel ED observation unit (EDOU)-based delayed comfort care pathway for ED patients on invasive mechanical ventilation and/or vasopressors was created in 2013 at Stanford Hospital.
Genet Mol Biol
January 2025
King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), College of Medicine, Riyadh, Saudi Arabia.
Sperm-associated antigen 9 (SPAG9) is a member of cancer-testis antigen, having characteristics of a scaffold protein, which is involved in the c-Jun N-terminal kinase JNK signaling pathway, suggesting its key involvement in different physiological processes, such as survival, apoptosis, tumorigenesis, and cell proliferation. We identified two families (A and B) having multisystem features like coarse facial features, albinism, cataracts, skeletal abnormalities, and developmental delay. Whole genome sequencing (WGS) in families A and B revealed a homozygous frameshift variant (c.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Mulliken Center for Theoretical Chemistry, Clausius Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms Universität Bonn, Beringstraße 4, 53115 Bonn, Germany.
With their narrow-band emission, high quantum yield, and good chemical stability, multiresonance thermally activated delayed fluorescence (MR-TADF) emitters are promising materials for OLED technology. However, accurately modeling key properties, such as the singlet-triplet (ST) energy gap and fluorescence energy, remains challenging. While time-dependent density functional theory (TD-DFT), the workhorse of computational materials science, suffers from fundamental issues, wave function-based coupled-cluster (CC) approaches, like approximate CC of second-order (CC2), are accurate but suffer from high computational cost and unfavorable scaling with system size.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!