Basic Mechanisms Research Articles

Acoustically Enhanced Triboelectric Stethoscope for Ultrasensitive Cardiac Sounds Sensing and Disease Diagnosis.

Electronic stethoscope used to detect cardiac sounds that contains essential clinical information is a primary tool for diagnosis of various cardiac disorders. However, the linear electro-mechanical constitutive relation makes conventional piezoelectric sensors rather ineffective to detect low-intensity, low-frequency heart acoustic signal without the assistance of complex filtering and amplification circuits. Herein, we find that triboelectric sensor features superior advantages over piezoelectric one for micro-quantity sensing originated from the fast saturated constitutive characteristic. As a result, the triboelectric sensor shows ultrahigh sensitivity (1215mV/Pa) than the piezoelectric counterpart (21mV/Pa) in the sound pressure range of 50 - 80dB under the same testing condition. By designing a trumpet-shaped auscultatory cavity with a power function cross-section to achieve acoustic energy converging and impedance matching, triboelectric stethoscope delivers 36dB signal-to-noise ratio for human test (2.3 times of that for piezoelectric one). Further combining with machine learning, five cardiac states can be diagnosed at 97% accuracy. In general, the triboelectric sensor is distinctly unique in basic mechanism, provides a novel design concept for sensing micromechanical quantities, and presents significant potential for application in cardiac sounds sensing and disease diagnosis. This article is protected by copyright. All rights reserved.

Steps into a Small World: First glimpses on everyday moment‐to‐moment decision making in an ecologically meaningful multi‐choice system for assessing animal preferences

AbstractThe behaviour shown by an animal at any one time is the consolidated output of its behavioural control mechanism. Moreover, what animals “want” is viewed as (the most) important component for individual welfare. Accordingly, studying the motivation of animals helps understanding basic mechanisms and welfare related needs. However, studying wants of animals is notoriously difficult and many previous studies on the preferences of animals have been restricted in the sense that only two choice options were presented in an artificial test environment. Here, an extended approach, the “Small World” is presented, in which the choices of animals between eight ecologically relevant resources can be observed in a long‐term test to reach conclusions with respect to everyday moment‐to‐moment decisions. In this sense, the system offers a quasi‐natural environment. The approach was tested in three experiments with observations of individual female rats, small groups of female rats (Long Evans, Rattus norvegicus) and small groups of female chickens (Lohmann Brown, Gallus gallus domesticus). The animals oriented themselves quickly in the system and it was possible to collect multifaceted data on the use of the resources. These data included the faecal and urinary markings in the Small World cages, the daily frequency and duration of visits to these cages, the sequential analyses of the choices for and decisions among the resources, and the synchrony of the animals in the groups. Given the richness of these data and the lack of a stress response in the tested animals, the use of the Small World approach seems to be highly promising as an extension to previously used procedures. To further improve the approach and more directly reflect the subjective value of the different resources from the animals' point of view, the distances between the resources in a quasi‐natural landscape shall be manipulated in future studies.

Ultrasound enhances the removal of V5+ in wastewater by ball-milled zero-valent iron: Effects and mechanisms

Vanadium is considered to be a harmful industrial pollutant that poses a serious threat to health. In this study, the effect of ultrasonic-enhanced ball milling zero-valent iron removal of vanadium in wastewater was investigated and the basic mechanism of this process was elucidated. The results of the study confirmed that the ultrasonic intervention significantly accelerated the vanadium removal rate and greatly shortened the time required to achieve equilibrium. Under certain experimental conditions, the removal efficiency of vanadium under ultrasonic conditions is 99.1 %, which is 1.4 times higher than that of the traditional constant-temperature water bath device (70.86 %). Analytical techniques such as electron paramagnetic resonance (EPR) and ultraviolet (UV) spectroscopy have confirmed that ultrasonic-induced cavitation and microjet phenomena actively stimulate the formation of more H radicals and Fe2+. The key role of Fe2+ in the removal reaction was further explored and confirmed by a quenching experiment. Through fitting the experimental data of different isothermal adsorption models and reaction kinetics, it is concluded that the adsorption process conforms to the pseudo-second-order kinetics and the Langmuir isothermal model. The adsorption process is dominated by chemisorption, and the maximum adsorption capacity is 153.033 mg·g−1. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and other analyses show that under the action of ultrasonic waves, V5+ is rapidly reduced to its lower oxidation state through reduction within the first 10 min of the reaction. Secondly, as the reaction progresses and the pH value increases, electrostatic adsorption and coprecipitation are involved in the removal reaction.

Update on human herpesvirus 7 pathogenesis and clinical aspects as a roadmap for future research.

Human herpesvirus 7 (HHV-7) is a common virus that is associated with various human diseases including febrile syndromes, dermatological lesions, neurological defects, and transplant complications. Still, HHV-7 remains one of the least studied members of all human betaherpesviruses. In addition, HHV-7-related research is mostly confined to case reports, while in vitro or in vivo studies unraveling basic virology, transmission mechanisms, and viral pathogenesis are sparse. Here, we discuss HHV-7-related literature linking clinical syndromes to the viral life cycle, epidemiology, and viral immunopathogenesis. Based on our review, we propose a hypothetical model of HHV-7 pathogenesis inside its host. Furthermore, we identify important knowledge gaps and recommendations for future research to better understand HHV-7 diseases and improve therapeutic interventions.

Human endogenous retrovirus W in multiple sclerosis: transcriptional activity is associated with decline in oligodendrocyte proportions in the white matter of the brain.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease. One of the basic mechanisms in this disease is the autoimmune response against the myelin sheet leading to axonal damage. There is strong evidence showing that this response is regulated by both genetic and environmental factors. In addition, the role of viruses has been extensively studied, especially in the case of human endogenous retroviruses (HERVs). However, although several associations with MS susceptibility, especially in the case of HERV-W family have been observed, the pathogenic mechanisms have remained enigmatic. To clarify these HERV-mediated mechanisms as well as the responsible HERV-W loci, we utilized RNA sequencing data obtained from the white matter of the brain of individuals with and without MS. CIBERSORTx tool was applied to estimate the proportions of neuronal, glial, and endothelial cells in the brain. In addition, the transcriptional activity of 215 HERV-W loci were analyzed. The results indicated that 65 HERV-W loci had detectable expression, of which 14 were differentially expressed between MS and control samples. Of these, 12 HERV-W loci were upregulated in MS. Expression levels of the 8 upregulated HERV-W loci had significant negative correlation with estimated oligodendrocyte proportions, suggesting that they are associated with the dynamics of oligodendrocyte generation and/or maintenance. Furthermore, Gene Set Enrichment Analysis (GSEA) results indicated that expression levels of three upregulated HERV-W loci: 2p16.2, 2q13, and Xq13.3, are associated with suppression of oligodendrocyte development and myelination. Taken together, these data suggest new HERV-W loci candidates that might take part in MS pathogenesis.

Exploring the potential of fennel (<i>Foeniculum vulgare</i> Mill.) as a valuable medicinal plant: a comprehensive (review)

Introduction. Foeniculum vulgare Mill., commonly known as fennel or drugstore dill, is very common as one of the world's oldest spice plants, which has significant economic importance and wide application in the pharmaceutical industry. In medical practice, the fruits of this plant are mainly used, which are included in the State Pharmacopoeia of the XIV edition and are a source of essential oil. They are used as an antispasmodic and carminative agent in the form of an infusion. Fennel grass harvested before flowering is used for food, as well as fruits, stems and inflorescences of the plant as a seasoning.Text. The purpose of this study is to summarize scientific papers on the morphological characteristics, phytochemical compounds, therapeutic properties and basic mechanisms of pharmacological activity of F. vulgare. A systematic literature search was conducted using relevant keywords such as "fennel", "Foeniculum vulgare Mill.", "therapeutic" and "pharmacology" in well-known databases, including ScienceDirect, Scopus, EBSCO and Medline. The search covered articles published before April 25, 2023 in available journals. The results of the study showed that fennel has a wide range of pharmacological properties, including antioxidant, anti-cancer, anti-inflammatory, antifungal, antibacterial and estrogenic effects. These effects can be explained by the presence of aromatic compounds, in particular anethole, estragole and fenchone, which are abundantly present in fennel.Conclusion. The diverse pharmacological properties and rich chemical composition of fennel make it a promising raw material for the development of new medicines. Further study of the therapeutic potential of fennel through in vivo and in vitro studies will contribute to the establishment of mechanisms of pharmacological action of biologically active substances (BAS) of fennel.

Intertextual satire in media discourse

Abstract The paper investigates intertextual satire in media discourse from the cognitive linguistic perspective. Within the frameworks of conceptual blending theory and the theory of precedent-related phenomena, we examine the cognitive processes of producing and understanding intertextual satire. By modelling conceptual integration networks, we aim to specify the cognitive mechanisms and operations involved in decoding intertextual satirical articles, drawing on examples from Private Eye magazine. The study demonstrates that the basic cognitive mechanism involved in creating intertextual satire is blending, and, in contrast to ironic utterances, which involve two contexts, in intertextual satire one and the same scenario unfolds in three contexts: real, fictional, and satirical. Thus, the blend that occurs as a result of combining real and fictional scenarios is verbalised and obvious to the recipient. The emergent structure, based on the blend, represents the intended (non-verbalised) meaning of intertextual satire, namely indirect criticism of the real situation under focus.

Development of an Educational Kit Using CAD Software for Simple Machine Learning

Traditional simple machine topic is frequently theoretical and does not provide enough hands-on practise. Students may as a result fail to comprehend the fundamentals of simple machines and their applications. This research presents an innovative educational kit for simple machine learning. Students can utilize this kit to understand the fundamental concepts behind simple machines like levers, gears, and pulleys. This study investigates the creation of a simple machine kit using CAD software as a teaching tool for fundamental mechanics. A survey study is employed as part of this technique in order to ascertain audience needs and expectations. Beginning with idea generation and followed by rigorous evaluation, the process of developing the kit focuses on aligning pedagogical viability, marketability, and profitability. The selected concept is then transformed into a detailed technical drawing specifying dimensions, components, and assembly instructions, ensuring coherence between educational goals and machine learning integration. Iterative prototyping and testing further refine the kit's design, ensuring seamless interaction between machine learning elements and LEGO-based components. This approach culminates in an innovative educational kit that effectively imparts foundational machine learning principles through an engaging platform. The simple machine kit made through this research can then be utilized as an educational tool in primary, secondary, or higher education environments to facilitate students' grasp of basic mechanics. Students learning product design may find this novel approach both enjoyable and useful in their studies.

Advanced Antimicrobial and Anti-Infective Strategies to Manage Peri-Implant Infection: A Narrative Review

Advanced Antimicrobial and Anti-Infective Strategies to Manage Peri-Implant Infection: A Narrative Review

Impact of bisphenol A and analogues eluted from resin-based dental materials on cellular and molecular processes: An insight on underlying toxicity mechanisms.

Dental resin systems, used for artificial replacement of teeth and their surrounding structures, have gained popularity due to the Food and Drug Administration's (FDA) recommendation to reduce dental amalgam use in high-risk populations and medical circumstances. Bisphenol A (BPA), an endocrine-disrupting chemical, is an essential monomer within dental resin in the form of various analogues and derivatives. Leaching of monomers from resins results in toxicity, affecting hormone metabolism and causing long-term health risks. Understanding cellular-level toxicity profiles of bisphenol derivatives is crucial for conducting toxicity studies in in vivo models. This review provides insights into the unique expression patterns of BPA and its analogues among different cell types and their underlying toxicity mechanisms. Lack of a consistent cell line for toxic effects necessitates exploring various cell lines. Among the individual monomers, BisGMA was found to be the most toxic; however, BisDMA and BADGE generates BPA endogenously and found to elicit severe adverse reactions. In correlating in vitro data with in vivo findings, further research is necessary to classify the elutes as human carcinogens or xenoestrogens. Though the basic mechanisms underlying toxicity were believed to be the production of intracellular reactive oxygen species and a corresponding decline in glutathione levels, several underlying mechanisms were identified to stimulate cellular responses at low concentrations. The review calls for further research to assess the synergistic interactions of co-monomers and other components in dental resins. The review emphasizes the clinical relevance of these findings, highlighting the necessity for safer dental materials and underscoring the potential health risks associated with current dental resin systems.

A Bayesian model calibration framework for stochastic compartmental models with both time-varying and time-invariant parameters

We consider state and parameter estimation for compartmental models having both time-varying and time-invariant parameters. In this manuscript, we first detail a general Bayesian computational framework as a continuation of our previous work. Subsequently, this framework is specifically tailored to the susceptible-infectious-removed (SIR) model which describes a basic mechanism for the spread of infectious diseases through a system of coupled nonlinear differential equations. The SIR model consists of three states, namely, the susceptible, infectious, and removed compartments. The coupling among these states is controlled by two parameters, the infection rate and the recovery rate. The simplicity of the SIR model and similar compartmental models make them applicable to many classes of infectious diseases. However, the combined assumption of a deterministic model and time-invariance among the model parameters are two significant impediments which critically limit their use for long-term predictions. The tendency of certain model parameters to vary in time due to seasonal trends, non-pharmaceutical interventions, and other random effects necessitates a model that structurally permits the incorporation of such time-varying effects. Complementary to this, is the need for a robust mechanism for the estimation of the parameters of the resulting model from data. To this end, we consider an augmented state vector, which appends the time-varying parameters to the original system states whereby the time evolution of the time-varying parameters are driven by an artificial noise process in a standard manner. Distinguishing between time-varying and time-invariant parameters in this fashion limits the introduction of artificial dynamics into the system, and provides a robust, fully Bayesian approach for estimating the time-invariant system parameters as well as the elements of the process noise covariance matrix. This computational framework is implemented by leveraging the robustness of the Markov chain Monte Carlo algorithm permits the estimation of time-invariant parameters while nested nonlinear filters concurrently perform the joint estimation of the system states and time-varying parameters. We demonstrate performance of the framework by first considering a series of examples using synthetic data, followed by an exposition on public health data collected in the province of Ontario.

Effects of doping with selected rare-earth elements (Eu3+, Dy3+, Eu3+/Dy3+) on the structural characteristics as well as electrical and luminescent properties of K0.5Na0.5NbO3.

The effects of adding Eu3+, Dy3+, and Eu3+/Dy3+ rare-earth elements on the microstructural, optical and electrical properties of lead-free piezoelectric materials based on K0.5Na0.5NbO3 (KNN) were investigated. A series of fine powders were synthesized via a modified Pechini route utilizing citric acid. Relatively large amounts of rare-earth elements were successfully incorporated into the crystal lattice of KNN. A combination of X-ray diffraction, X-ray absorption spectroscopy, energy-dispersive X-ray and scanning electron microscopy were used to characterize the structure and chemical composition of the powders and sinters. XRD patterns indicated the formation of a single-phase orthorhombic structure in the co-doped sinter. X-ray absorption spectroscopy revealed the nominal 3+ valence states of Eu and Dy in KNN ceramic sinters. The Mott model and group symmetry theory were used to discuss the characteristics of Raman spectra obtained for the EuDy:KNN ceramics. The ceramics exhibited good dielectric permittivity (ε≃1300) and low dielectric loss (tan δ=0.03) in the temperature range of 170-240°C. The electrical properties of the ceramics showed that the basic mechanism of conduction and relaxation was thermal activation, and that small polaron hopping was responsible for charge carrying. The Eu3+ and Dy3+ ions displayed characteristic red and orange emissions in sinters when excited with light in the wide ultraviolet spectra range (380-420nm).

Vascular Organization: Lessons from Development and Disease.

Organ formation requires tight coordination with vascular growth. Intricate networks of blood vessels course through all organs and tissues and are composed of both endothelial cells (ECs) and associated mural cells. Despite decades of research into the biology of blood vessel formation and homeostasis, little is known about how the vasculature ensures its properly coordinated growth and intimate development with the cells of different organs. Even more mystifying is how a highly dynamic endothelium quiesces to differentiate into mature vessels, and how disruption of this mature quiescence results in pathological conditions. Interestingly, both intra- and interorgan vascular architecture hold critical importance to the maintenance of blood vessels, as the rate of flow and supply of supportive angiogenic factors can be altered with deleterious effects. In this article, we review the basic mechanisms of blood vessel formation and maintenance with an emphasis on organ-specific vascular development, and we examine the case of transient pulmonary arteriovenous malformations as a case study of vascular homeostatic mechanisms.

Concise Review on Scientific Approaches to Burns and Scars.

Burns are large open surgical lesions bathed in virulent pus that result in rupturing of the cutaneous membrane, which has serious consequences such as an extensive loss of proteins, and body fluids, increased chances of infections, and sometimes death. These can be classified based on their penetration levels, i.e., first-degree burns penetrating the epidermis, second-degree burns including both epidermis and dermis, third-degree burns to both layers including the hair follicular cells, sweat glands and various core tissues, fourth-degree burns to adipose tissue, fifth stage burns to muscles, and sixth stage burns to bones. Wound healing/wound repair is a very perplexing process in which the tissues of the affected/burnt area repairs themselves to attain their original form and functionality but develop a scar at the wound site. This article mainly focuses on the algorithms to differentiate various degrees of burns, general first aid approaches to burns and scars, the rationale of treatment of burns, basic mechanisms highlighting the healing processes in humans in terms of free from scar formation as well as with scar formation at their elementary levels including cellular as well as biochemical levels, utility, and progression of pre-clinical data to humans and finally approaches for the improvement of scar formation in man.

Electro-fluid-dynamics (EFD) of soft-bodied organisms swimming through mucus having dilatant, viscous, and pseudo-plastic properties

The sperm propelling mechanism has been proposed as a possible resource for soft micro-robots in confined spaces, with potential applications in biomedical engineering. Human sperm cells essentially swim through the non-Newtonian liquid (cervical mucus) to reach their target. Thus, sperm cells swimming through non-Newtonian fluids is not vital only for physiology, but also for the fabrication of swimming micro-robots. Inspired by these remarkable applications, we examine the basic mechanics of spermatozoa motility using an undulating sheet model. This undulating sheet is bounded between two rigid walls which is self-propeling in the negative axial direction. The liquid around the spermatozoa is taken as Carreau fluid with electro-osmotic properties. The application of the lubrication approximation results in the reduction of momentum equations. The resulting ODE is solved numerically via the finite difference method and MATLAB’s built-in routine bvp5c. The unknowns that are present in the boundary conditions are refined by the root-finding algorithm. Power losses, cell speed, flow rate, velocity of the fluid, and streamline pattern are visualized by graphs. The findings of this study have important implications for the designing and optimization of electrically controlled microswimmers.

Photoresponsive Smart Hydrogels and Their Versatile Applications: A Review

Stimuli responsive hydrogels are emerging as smart materials due to their tunable chemical and physical properties in response to various stimuli like pH, temperature, chemicals, pressure, electrical or light. Photoresponsive hydrogels are more attractive for versatile applications as their properties can be manipulated via contact free fine tuning of wavelength and intensity of light. If designed properly photoresponsive hydrogels could also have inherent biocompatibility. Their smart responsiveness along with biocompatibility have made them suitable for applications in versatile fields starting from drug delivery, cell-culture to surface modification and soft-robotics. In this review article, basic mechanisms responsible for photo-responsiveness in hydrogels along with their potential applications are discussed.

In Vitro Identification of Phosphorylation Sites on TcPolβ by Protein Kinases TcCK1, TcCK2, TcAUK1, and TcPKC1 and Effect of Phorbol Ester on Activation by TcPKC of TcPolβ in Trypanosoma cruzi Epimastigotes

Chagas disease is caused by the single-flagellated protozoan Trypanosoma cruzi, which affects several million people worldwide. Understanding the signal transduction pathways involved in this parasite’s growth, adaptation, and differentiation is crucial. Understanding the basic mechanisms of signal transduction in T. cruzi could help to develop new drugs to treat the disease caused by these protozoa. In the present work, we have demonstrated that Fetal Calf Serum (FCS) can quickly increase the levels of both phosphorylated and unphosphorylated forms of T. cruzi DNA polymerase beta (TcPolβ) in tissue-cultured trypomastigotes. The in vitro phosphorylation sites on TcPolβ by protein kinases TcCK1, TcCK2, TcAUK1, and TcPKC1 have been identified by Mass Spectrometry (MS) analysis and with antibodies against phosphor Ser-Thr-Tyr. MS analysis indicated that these protein kinases can phosphorylate Ser and Thr residues on several sites on TcPolβ. Unexpectedly, it was found that TcCK1 and TcPKC1 can phosphorylate a different Tyr residue on TcPolβ. By using a specific anti-phosphor Tyr monoclonal antibody, it was determined that TcCK1 can be in vitro autophosphorylated on Tyr residues. In vitro and in vivo studies showed that phorbol 12-myristate 13-acetate (PMA) can activate the PKC to stimulate the TcPolβ phosphorylation and enzymatic activity in T. cruzi epimastigotes.

Advances in Understanding the Evolution Mechanism of Micropore Defects in Metal Materials under External Loads

Micropores are one of the critical factors affecting materials’ performance and service life. As the need for a deeper understanding of micropore evolution and damage mechanisms grows, assessing the mechanical properties of materials containing micropores and predicting the lifespan of related metal structural components becomes increasingly complex. This paper focuses on the evolution process, regularities, and research methods of micropores in metal materials. Based on recent research and practical applications, the key stages of micropore evolution are discussed, encompassing nucleation, growth, coalescence, collapse, interaction, and the influence of other microstructures. Firstly, the advantages and limitations of commonly used characterization methods such as scanning electron microscopy, transmission electron microscopy, and X-ray computed tomography are introduced in the study of micropore evolution. Subsequently, critical theoretical models for micropore evolution, such as the Gurson model and its extensions, are summarized. By using a multiscale approach combining the crystal plasticity finite element method, dislocation dynamics, and molecular dynamics, the factors influencing the micropore evolution, such as external stress conditions, internal microstructures, and micropore characteristics, are specifically elaborated, and the basic physical mechanisms of micropore evolution are analyzed. Finally, a comprehensive review and summary of current research trends and key findings are provided, and a forward-looking perspective on future research directions is presented.

The Interplay between Antibiotics and the Host Immune Response in Sepsis: From Basic Mechanisms to Clinical Considerations: A Comprehensive Narrative Review

Sepsis poses a significant global health challenge due to immune system dysregulation. This narrative review explores the complex relationship between antibiotics and the immune system, aiming to clarify the involved mechanisms and their clinical impacts. From pre-clinical studies, antibiotics exhibit various immunomodulatory effects, including the regulation of pro-inflammatory cytokine production, interaction with Toll-Like Receptors, modulation of the P38/Pmk-1 Pathway, inhibition of Matrix Metalloproteinases, blockade of nitric oxide synthase, and regulation of caspase-induced apoptosis. Additionally, antibiotic-induced alterations to the microbiome are associated with changes in systemic immunity, affecting cellular and humoral responses. The adjunctive use of antibiotics in sepsis patients, particularly macrolides, has attracted attention due to their immune-regulatory effects. However, there are limited data comparing different types of macrolides. More robust evidence comes from studies on community-acquired pneumonia, especially in severe cases with a hyper-inflammatory response. While studies on septic shock have shown mixed results regarding mortality rates and immune response modulation, conflicting findings are also observed with macrolides in acute respiratory distress syndrome. In conclusion, there is a pressing need to tailor antibiotic therapy based on the patient’s immune profile to optimize outcomes in sepsis management.

Optogenetic stimulation of medial septal glutamatergic neurons modulates theta-gamma coupling in the hippocampus

Hippocampal cross-frequency theta-gamma coupling (TGC) is a basic mechanism for information processing, retrieval, and consolidation of long-term and working memory. While the role of entorhinal afferents in the modulation of hippocampal TGC is widely accepted, the influence of other main input to the hippocampus, from the medial septal area (MSA, the pacemaker of the hippocampal theta rhythm) is poorly understood. Optogenetics allows us to explore how different neuronal populations of septohippocampal circuits control neuronal oscillations in vivo. Rhythmic activation of septal glutamatergic neurons has been shown to drive hippocampal theta oscillations, but the role of these neuronal populations in information processing during theta activation has remained unclear. Here we investigated the influence of phasic activation of MSA glutamatergic neurons expressing channelrhodopsin II on theta-gamma coupling in the hippocampus. During the experiment, local field potentials of MSA and hippocampus of freely behaving mice were modulated by 470 nm light flashes with theta frequency (2–10) Hz. It was shown that both the power and the strength of modulation of gamma rhythm nested on hippocampal theta waves depend on the frequency of stimulation. The modulation of the amplitude of slow gamma rhythm (30–50 Hz) prevailed over modulation of fast gamma (55–100 Hz) during flash trains and the observed effects were specific for theta stimulation of MSA. We discuss the possibility that phasic depolarization of septal glutamatergic neurons controls theta-gamma coupling in the hippocampus and plays a role in memory retrieval and consolidation.