Rhythmic Oscillations Research Articles

A highly stable electrode with low electrode-skin impedance for wearable brain-computer interface

To date, brain-computer interfaces (BCIs) have proved to play a key role in many medical applications, for example, the rehabilitation of stroke patients. For post-stroke rehabilitation, the BCIs require the EEG electrodes to precisely translate the brain signals of patients into intended movements of the paralyzed limb for months. However, the gold standard silver/silver-chloride electrodes cannot satisfy the requirements for long-term stability and preparation-free recording capability in wearable EEG devices, thus limiting the versatility of EEG in wearable BCI applications over time outside the rehabilitation center. Here, we design a long-term stable and low electrode-skin interfacial impedance conductive polymer-hydrogel EEG electrode that maintains a lower impedance value than gel-based electrodes for 29 days. With this technology, EEG-based long-term and wearable BCIs could be realized in the near future. To demonstrate this, our designed electrode is applied for a wireless single-channel EEG device that detects changes in alpha rhythms in eye-open/eye-close conditions. In addition, we validate that the designed electrodes could capture oscillatory rhythms in motor imagery protocols as well as low-frequency time-locked event-related potentials from healthy subjects, with similar or better performance than gel-based electrodes. Finally, we demonstrate the use of the designed electrode in online BCI-based functional electrical stimulation, which could be used for post-stroke rehabilitation.

Identifying hub circadian rhythm biomarkers and immune cell infiltration in rheumatoid arthritis.

BackgroundRheumatoid arthritis (RA) is a chronic systemic autoimmune disease with symptoms characterized by typical circadian rhythmic changes. This study aimed to identify the hub circadian rhythm genes (CRGs) in RA and explore their association with immune cell infiltration and pathogenesis of RA.MethodsThe differentially expressed CRGs (DECRGs) between RA and normal control samples were screened from Datasets GSE12021 and GSE55235. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis were used to explore the potential functional mechanisms of DECRGs in RA. Weighted Gene Co-expression Network Analysis and Least Absolute Shrinkage and Selection Operator regression analysis were performed to identify hub CRGs of RA. CIBERSORT was conducted to compare the infiltration level of immune cells in RA and control synovial tissue and their relationship with hub genes. In addition, the diagnostic value of hub biomarkers was evaluated by the area under the receiver operator characteristic curve. Further, a nomogram prediction model was constructed and its significance for clinical decision-making was evaluated.ResultsThe green module was identified as the hub module associated with RA. Four hub CRGs (EGR1, FOSL2, GADD45B, and NFIL3) were identified and showed that they had the highest specificity and sensitivity for RA diagnosis, respectively. The expression levels and diagnostic values of these genes were externally validated in the dataset GSE55457. A nomogram prediction model based on the four hub CRGs was constructed and proved to have a certain clinical decision value. Additionally, the correlation analysis of immune cells with hub genes showed that all hub genes were significantly positively correlated with activated mast cells, resting memory CD4+ T cells, and monocytes. Whereas, all hub genes were negatively correlated with plasma cells, CD8+ T cells, and activated memory CD4+ T cells. Meanwhile, FOSL2 and GADD45B were negatively correlated with Tfh cells.ConclusionFour hub CRGs were identified and showed excellent diagnostic value for RA. These genes may be involved in the pathological process of RA by disrupting the rhythmic oscillations of cytokines through immune-related pathways and could be considered molecular targets for future chronotherapy against RA.

Vertical ground reaction force oscillation during standing on hard and compliant surfaces: The "postural rhythm".

When a person stands upright quietly, the position of the Centre of Mass (CoM), the vertical force acting on the ground and the geometrical configuration of body segments is accurately controlled around to the direction of gravity by multiple feedback mechanisms and by integrative brain centres that coordinate multi-joint movements. This is not always easy and the postural muscles continuously produce appropriate torques, recorded as ground reaction force by a force platform. We studied 23 young adults during a 90 s period, standing at ease on a hard (Solid) and on a compliant support (Foam) with eyes open (EO) and with eyes closed (EC), focusing on the vertical component of the ground reaction force (VGRF). Analysis of VGRF time series gave the amplitude of their rhythmic oscillations (the root mean square, RMS) and of their frequency spectrum. Sway Area and Path Length of the Centre of Pressure (CoP) were also calculated. VGRF RMS (as well as CoP sway measures) increased in the order EO Solid ≈ EC Solid < EO Foam < EC Foam. The VGRF frequency spectra featured prevailing frequencies around 4–5 Hz under all tested conditions, slightly higher on Solid than Foam support. Around that value, the VGRF frequencies varied in a larger range on hard than on compliant support. Sway Area and Path Length were inversely related to the prevailing VGRF frequency. Vision compared to no-vision decreased Sway Area and Path Length and VGRF RMS on Foam support. However, no significant effect of vision was found on VGRF mean frequency for either base of support condition. A description of the VGRF, at the interface between balance control mechanisms and sway of the CoP, can contribute information on how upright balance is maintained. Analysis of the frequency pattern of VGRF oscillations and its role in the maintenance of upright stance should complement the traditional measures of CoP excursions in the horizontal plane.

The role of clock gene BMAL1 in exercise-induced skeletal muscle injury recovery

Objective: To investigate the role of clock gene BMAL1 in exercise-induced skeletal muscle injury recovery. Methods: Two hundred and eight 8-week-old SD rats were randomly divided into the control group (Group C, n=104) and the exercise group (Group E, n=104). Group E performed a 90-minute downhill run on the treadmill. After exercise, the gastrocnemius muscle of 8 rats in Group C and Group E were collected at 0 h, 6 h, 12 h, 18 h, 24 h, 30 h, 36 h, 42 h, 48 h, 54 h, 60 h, 66 h and 72 h. The expression of skeletal muscle core clock gene, BMAL1 was measured by real-time fluorescence quantitative PCR. The parameters of fitting cosine curve were obtained by cosine analysis software circacompare (R package), and the change trend of rhythmic oscillation was analyzed. The ultrastructure of skeletal muscle fibers was observed by transmission electron microscope. The expressions of skeletal muscle BMAL1 and DESMIN were detected by Western blot; Immunofluorescence was used to observe the localization and contents of BMAL1 and DESMIN. Results: In Group C, three complete circadian rhythm cycles of mRNA BMAL1 were observed within 72 hours; in Group E, the circadian rhythm of BMAL1 mRNA disappeared at 0 h～24 h. Compared with Group C, the expression level of BMAL1 mRNA was significantly increased at 0 h, 6 h, 12 h, and 18 h after exercise in Group E (P＜0.05), and the expression of BMAL1 protein was significantly increased at 0 h and 12 h after exercise(P＜0.05), and recovered to the level of that in Group C from 24 h to 72 h(P＞0.05). The expression of DESMIN protein was decreased at 0 h and 12 h after exercise(P＜0.05), gradually increased at 24 h, increased significantly at 48 h(P＜0.01), and recovered to the control level at 72 h (P＞0.05). In Group E, BMAL1 and DESMIN were co-localized at 0 h, 12 h, and 24 h after exercise; the colocalization at 0 h～24 h showed a trend of first decreasing and then increasing, and the fluorescence intensity at 24 h reached the highest value. Conclusion: The post-exercise clock gene BMAL1 may be involved in the enhanced synergy of regulating the cytoskeletal protein DESMIN, it is thus related to the promotion of muscle fiber structure recovery.

Brain-heart interactions are modulated across the respiratory cycle via interoceptive attention

Respiration and heartbeat continuously interact within the living organism at many different levels, representing two of the main oscillatory rhythms of the body and providing major sources of interoceptive information to the brain. Despite the modulatory effect of respiration on exteroception and cognition has been recently established in humans, its role in shaping interoceptive perception has been scarcely investigated so far.In two independent studies, we investigated the effect of spontaneous breathing on cardiac interoception by assessing the Heartbeat Evoked Potential (HEP) in healthy humans. In Study 1, we compared HEP activity for heartbeats occurred during inhalation and exhalation in 40 volunteers at rest. We found higher HEP amplitude during exhalation, compared to inhalation, over fronto-centro-parietal areas. This suggests increased brain-heart interactions and improved cortical processing of the heartbeats during exhalation. Further analyses revealed that this effect was moderated by heart rate changes. In Study 2, we tested the respiratory phase-dependent modulation of HEP activity in 20 volunteers during Exteroceptive and Interoceptive conditions of the Heartbeat Detection (HBD) task. In these conditions, participants were requested to tap at each heartbeat, either listened to or felt, respectively. Results showed higher HEP activity and higher detection accuracy at exhalation than inhalation in the Interoceptive condition only. Direct comparisons of Interoceptive and Exteroceptive conditions confirmed stronger respiratory phase-dependent modulation of HEP and accuracy when attention was directed towards the interoceptive stimuli. Moreover, HEP changes during the Interoceptive condition were independent of heart physiology, but were positively correlated with higher detection accuracy at exhalation than inhalation. This suggests a link between optimization of cortical processing of cardiac signals and detection of heartbeats across the respiratory cycle.Overall, we provide data showing that respiration shapes cardiac interoception at the neurophysiological and behavioural levels. Specifically, exhalation may allow attentional shift towards the internal bodily states.

The clock component OsLUX regulates rice heading through recruiting OsELF3-1 and OsELF4s to repress Hd1 and Ghd7

IntroductionCircadian clocks coordinate internal physiology and external environmental factors to regulate cereals flowering, which is critical for reproductive growth and optimal yield determination. ObjectivesIn this study, we aimed to confirm the role of OsLUX in flowering time regulation in rice. Further research illustrates how the OsELF4s–OsELF3-1–OsLUX complex directly regulates flowering-related genes to mediate rice heading. MethodsWe identified a circadian gene OsLUX by the MutMap method. The transcription levels of flowering-related genes were evaluated in WT and oslux mutants. OsLUX forms OsEC (OsELF4s–OsELF3-1–OsLUX) complex were supported by yeast two-hybrid, pull down, BiFC, and luciferase complementation assays (LCA). The EMSA, Chip-qPCR, luciferase luminescence images, and relative LUC activity assays were performed to examine the targeted regulation of flowering genes by the OsEC (OsELF4s–OsELF3-1–OsLUX) complex. ResultsThe circadian gene OsLUX encodes an MYB family transcription factor that functions as a vital circadian clock regulator and controls rice heading. Defect in OsLUX causes an extremely late heading phenotype under natural long-day and short-day conditions, and the function was further confirmed through genetic complementation, overexpression, and CRISPR/Cas9 knockout. OsLUX forms the OsEC (OsELF4s–OsELF3-1–OsLUX) complex by recruiting OsELF3-1 and OsELF4s, which were required to regulate rice heading. OsELF3-1 contributes to the translocation of OsLUX to the nucleus, and a compromised flowering phenotype results upon mutation of any component of the OsEC complex. The OsEC complex directly represses Hd1 and Ghd7 expression via binding to their promoter's LBS (LUX binding site) element. ConclusionOur findings show that the circadian gene OsLUX regulates rice heading by directly regulating rhythm oscillation and core flowering-time-related genes. We uncovered a mechanism by which the OsEC target suppresses the expression of Hd1 and Ghd7 directly to modulate photoperiodic flowering in rice. The OsEC (OsELF4s–OsELF3-1–OsLUX)–Hd1/Ghd7 regulatory module provides the genetic targets for crop improvement.

The Developmental Eye Movement Test Does Not Detect Oculomotor Problems: Evidence from Children with Nystagmus.

SIGNIFICANCEThe Developmental Eye Movement (DEM) test, a test purported to assess oculomotor skills, does not detect eye movement disorder in nystagmus syndromes. The test should not be used for the clinical evaluation of oculomotor disorders.PURPOSEThe DEM test ratio compares a horizontal number naming subtest with a vertical one to identify oculomotor problems independent of a child's visual-verbal naming skills. Here, we tested the construct validity of this method by comparing scores of children with and without pathologic nystagmus. Such a nystagmus disturbs normal fixation and saccadic behavior because of the presence of involuntary rhythmic oscillations of the eyes. Therefore, if the ratio is indeed a comprehensive measure of oculomotor problems, children with nystagmus should show an increased ratio score.METHODSThe DEM test performances of normally sighted children (n = 94), children with ocular visual impairments (VIo; n = 33), and children with cerebral visual impairment (n = 30) were analyzed using linear regression. Part of the children with VIo and cerebral visual impairment had either fusion maldevelopment nystagmus syndrome (n = 8) or infantile nystagmus syndrome (n = 20), whereas the others showed no pathologic nystagmus.RESULTSThe times needed for the horizontal and vertical subtests were significantly different between children with normal vision, VIo, and cerebral visual impairment (P < .001). However, the presence of nystagmus did not add significantly to the horizontal and vertical times (P > .20), nor did it have an effect on the ratio (P > .10).CONCLUSIONSThe DEM test ratio is not sensitive to fixation and saccade abnormalities associated with nystagmus, indicating that it does not have general construct validity to detect true eye movement disorders. Although not suitable for the evaluation of oculomotor disorders, the subtests do have clinical relevance in the diagnosis of cerebral visual impairment.

Cryptochrome 1 is involved in anti-bacterial immunity in Japanese flounder (Paralichthys olivaceus)

Cryptochrome is a pivotal protein of the core regulatory machinery in circadian clock and participates in various biological processes including immunity. In fish, the immunological functionality of Cryptochrome is unclear. In this study, we profiled the expression pattern of Japanese flounder cryptochrome 1 (named PoCry1) and investigated its involvement in the immune response during bacterial infection. PoCry1 is approximately 75% identical in amino acid sequence to mammalian Cryptochrome 1 and possesses the conserved DNA photolyase domain and FAD binding domain. Its transcription was detected in 10 flounder tissues and was reduced upon Vibrio harveyi challenge. The transcription of PoCry1 exhibited apparent rhythmic oscillation upon the light actuation of a day-night cycle in different tissues. The knockdown of PoCry1 resulted in significant augment of inflammatory cytokine expression. During bacterial infection, PoCry1 silencing led to increase in cytokine expression and decrease in bacterial dissemination, which could be neutralized by a specific PKA inhibitor, suggesting PoCry1 is likely able to negatively modulate the immune response to bacterial infection through PKA associated pathways.Taken together, our results revealed that PoCry1 is circadian oscillated in transcription upon rhythmic light stimulation and involved in anti-infection immunity, thus enlightening that light condition as a circadian zeitgeber could be exploited to strength fish immune system and benefit disease control in aquaculture.

The role of brain oscillations in post-stroke motor recovery: An overview.

Stroke is the second cause of disability and death worldwide, highly impacting patient’s quality of life. Several changes in brain architecture and function led by stroke can be disclosed by neurophysiological techniques. Specifically, electroencephalogram (EEG) can disclose brain oscillatory rhythms, which can be considered as a possible outcome measure for stroke recovery, and potentially shaped by neuromodulation techniques. We performed a review of randomized controlled trials on the role of brain oscillations in patients with post-stroke searching the following databases: Pubmed, Scopus, and the Web of Science, from 2012 to 2022. Thirteen studies involving 346 patients in total were included. Patients in the control groups received various treatments (sham or different stimulation modalities) in different post-stroke phases. This review describes the state of the art in the existing randomized controlled trials evaluating post-stroke motor function recovery after conventional rehabilitation treatment associated with neuromodulation techniques. Moreover, the role of brain pattern rhythms to modulate cortical excitability has been analyzed. To date, neuromodulation approaches could be considered a valid tool to improve stroke rehabilitation outcomes, despite more high-quality, and homogeneous randomized clinical trials are needed to determine to which extent motor functional impairment after stroke can be improved by neuromodulation approaches and which one could provide better functional outcomes. However, the high reproducibility of brain oscillatory rhythms could be considered a promising predictive outcome measure applicable to evaluate patients with stroke recovery after rehabilitation.

Endogenous ceramide phosphoethanolamine modulates circadian rhythm via neural-glial coupling in Drosophila.

While endogenous lipids are known to exhibit rhythmic oscillations, less is known about how specific lipids modulate circadian behavior. Through a series of loss-of-function and gain-of-function experiments on ceramide phosphoethanolamine (CPE) synthase of Drosophila, we demonstrated that pan-glial-specific deficiency in membrane CPE, the structural analog of mammalian sphingomyelin (SM), leads to arrhythmic locomotor behavior and shortens lifespan, while the reverse is true for increasing CPE. Comparative proteomics uncovered dysregulated synaptic glutamate utilization and transport in CPE-deficient flies. An extensive genetic screen was conducted to verify the role of differentially expressed proteins in circadian regulation. Arrhythmic locomotion under cpes1 mutant background was rescued only by restoring endogenous CPE or SM through expressing their respective synthases. Our results underscore the essential role of CPE in maintaining synaptic glutamate homeostasis and modulating circadian behavior in Drosophila. The findings suggest that region-specific elevations of functional membrane lipids can benefit circadian regulation.

Fine Mapping and Functional Research of Key Genes for Photoperiod Sensitivity in Maize.

Maize is native to the tropics and is very sensitive to photoperiod. Planting in temperate regions with increased hours of daylight always leads to late flowering, sterility, leggy plants, and increased numbers of maize leaves. This phenomenon severely affects the utilization of tropical maize germplasm resources. The sensitivity to photoperiod is mainly reflected in differences in plant height (PH), ear height (EH), total leaf number (LN), leaf number under ear (LE), silking stage (SS), and anthesis stage (AT) in the same variety under different photoperiod conditions. These differences are more pronounced for varieties that are more sensitive to photoperiod. In the current study, a high-density genetic map was constructed from a recombinant inbred line (RIL) population containing 209 lines to map the quantitative trait loci (QTL) for photoperiod sensitivity of PH, EH, LN, LE, SS, and AT. A total of 39 QTL were identified, including three consistent major QTL. We identified candidate genes in the consensus major QTL region by combined analysis of transcriptome data, and after enrichment by GO and KEGG, we identified a total of four genes (Zm00001d006212, Zm00001d017241, Zm00001d047761, and Zm00001d047632) enriched in the plant circadian rhythm pathway (KEGG:04712). We analyzed the expression levels of these four genes, and the analysis results showed that there were significant differences in response under different photoperiod conditions for three of them (Zm00001d047761, Zm00001d006212 and Zm00001d017241). The results of functional verification showed that the expression patterns of genes rhythmically oscillated, which can affect the length of the hypocotyl and the development of the shoot apical meristem. We also found that the phenotypes of the positive plants were significantly different from the control plants when they overexpressed the objective gene or when it was knocked out, and the expression period, phase, and amplitude of the target gene also shifted. The objective gene changed its own rhythmic oscillation period, phase, and amplitude with the change in the photoperiod, thereby regulating the photoperiod sensitivity of maize. These results deepen our understanding of the genetic structure of photoperiod sensitivity and lay a foundation for further exploration of the regulatory mechanism of photoperiod sensitivity.

Genome-Wide Identification, Characterization, and Expression Profile Analysis of CONSTANS-like Genes in Woodland Strawberry (Fragaria vesca).

CONSTANS-like (CO-like) gene is one of the most important regulators in the flowering process of the plant, playing a core role in the photoperiodic flowering induction pathway. In this study, we identified 10 distinct CO-like genes (FveCOs) in woodland strawberry (Fragaria vesca). They were classified into three groups with specific gene structure characteristics or protein domains in each group. The effect of selection pressure on the FveCOs in the woodland strawberry was tested by Ka/Ks, and it was shown that the evolution rate of FveCOs was controlled by purification selection factors. Intraspecific synteny analysis of woodland strawberry FveCOs showed that at least one duplication event existed in the gene family members. Collinearity analysis of woodland strawberry genome with genomes of Arabidopsis, rice (Oryza sativa), and apple (Malus × domestica) showed that CO-like genes of F. vesca and Malus × domestica owned higher similarity for their similar genomes compared with those of other two species. The FveCOs showed different tissue-specific expression patterns. Moreover, real-time quantitative PCR results revealed that the expressions of the most FveCOs followed a 24-h rhythm oscillation under both long-day (LD) and short-day (SD) conditions. Further expression analysis showed that the individual expression changing profile of FveCO3 and FveCO5 was opposite to each other under both LD and SD conditions. Moreover, the expression of FveCO3 and FveCO5 was both negatively correlated with the flowering time variation of the woodland strawberry grown under LD and SD conditions, indicating their potential vital roles in the photoperiodic flowering regulation. Further protein interaction network analysis also showed that most of the candidate interaction proteins of FveCO3 and FveCO5 were predicted to be the flowering regulators. Finally, LUC assay indicated that both FveCO3 and FveCO5 could bind to the promoter of FveFT1, the key regulator of flowering regulation in the woodland strawberry, and thus activate its expression. Taken together, this study laid a foundation for understanding the exact roles of FveCOs in the reproductive development regulation of the woodland strawberry, especially in the photoperiodic flowering process.

Dynamic theta-modulated high frequency oscillations in rat medial prefrontal cortex during spatial working memory task

Interaction of oscillatory rhythms at different frequencies is considered to provide a neuronal mechanism for information processing and transmission. These interactions have been suggested to have a vital role in cognitive functions such as working memory and decision-making. Here, we investigated the medial prefrontal cortex (mPFC), which is known to have a critical role in successful execution of spatial working memory tasks. We recorded local field potential oscillations from mPFC while rats performed a delayed-non-match-to-place (DNMTP) task. In the DNMTP task, the rat needed to decide actively about the pathway based on the information remembered in the first phase of each trial. Our analysis revealed a dynamic phase-amplitude coupling (PAC) between theta and high frequency oscillations (HFOs). This dynamic coupling emerged near the turning point and diminished afterward. Further, theta activity during the delay period, which is thought of as the maintenance phase, in the absence of the coupling, can predict task completion time. We previously reported diminished rat performance in the DNMTP task in response to electromagnetic radiation. Here, we report an increase in the theta rhythm during delay activity besides diminishing the coupling after electromagnetic radiation. These findings suggest that the different roles of the mPFC in working memory could be supported by separate mechanisms: Theta activity during the delay period for information maintenance and theta-HFOs phase-amplitude coupling relating to the decision-making procedure.

Dydrogesterone and levonorgestrel at environmentally relevant concentrations have antagonist effects with rhythmic oscillation in brain and eyes of zebrafish.

Synthetic progestins levonorgestrel (LNG) and dydrogesterone (DDG) are frequency detected in surface water. Combined effects of LNG and DDG on gonad differentiation are similar to LNG single exposure in juvenile zebrafish. However, LNG and DDG mixtures have stronger effects on spermatogenesis in testes of adult zebrafish, which show variable at different life stage. Effects of LNG and DDG mixtures on eyes and brain remain unknown. Here we investigated effects of LNG, DDG and their mixtures on eyes and brain. Zebrafish were exposed to LNG, DDG and their mixtures from 2 hpf to 144 dpf. Rhythm and vision related biological processes were enriched in eyes and brain in LNG and DDG treatments, which indicated rhythmic oscillation in eyes and brain. The qPCR data revealed that both LNG and DDG decreased transcription of arntl2 and clocka, while increased transcription of per1a, per1b, rpe65a and tefa in eyes and brain. However, DDG and LNG mixtures had slight effect on transcription of genes related to rhythm and vision. In addition, LNG and DDG reduced the thickness of inner nuclear layer in the eyes. Bliss independent model revealed that LNG and DDG had antagonist effects on transcription and histology in eyes and brain. Moreover, LNG and DDG formed the same hydrogen bonds with green-sensitive opsin-4 and rhodopsin kinase GRK7a. Taken together, LNG and DDG competed with each other for the same binding residues resulting in antagonist effect in their mixtures treatments, and have significant ecological implications to assess combined effects of progestins mixtures on fish in different organs.

Impact of the COVID-19 pandemic on individuals with nystagmus and an exploration of public assumptions about the condition: an electronic questionnaire study

PurposeNystagmus is a disorder characterized by uncontrolled, rhythmic oscillations of the eyes. It often causes reduced visual function beyond reduced visual acuity alone. There is a paucity of literature regarding the public understanding of nystagmus, and there are no published data on the impact of the COVID-19 pandemic on people living with the condition. This study explores the self-reported impact of the COVID-19 pandemic on those with nystagmus, and examines both public understanding of how nystagmus affects people who have it and the perceptions of public understanding by those with the condition and their carers.MethodsA qualitative questionnaire was designed following a stakeholder engagement process. This questionnaire was advertised via social media platforms and charity websites to achieve widespread recruitment. Data were collected between November and December 2020. Participants were divided into two groups based on their response to the question: “Do you, or anyone you know well, have nystagmus?”. Questions were posed to participants in a purpose-built, branching survey. The resulting data were analyzed using descriptive and inferential statistical methods.ResultsOne thousand six hundred forty-five respondents were recruited, of which 849 (51.6%) answered “Yes” to the initial filtering question. Analysis showed that, broadly, public understanding of nystagmus differs from the perception of it by those with nystagmus and their carers, that the COVID-19 pandemic has had a significant impact on those with nystagmus, and that respondents who have met someone with nystagmus, even briefly, tend to have a greater understanding of the impact of the condition.ConclusionThis study highlights the lack of public awareness regarding nystagmus and suggests opportunities to increase the awareness of nystagmus without the need for extensive knowledge of the condition. The COVID-19 pandemic has posed additional difficulties for those living with nystagmus, which is likely to be comparable among those with similar ocular disorders.

Review on circadian rhythm the role of core clock gene expression during sleep in epileptic syndrome

Circadian rhythm is a 24 hour or a day’s rhythmic oscillations with physiological and behavioural changes that is internally governed by the brain. This activity is generally anticipated by the internal and external cues from the environment. In circadian rhythm of our body is regulated by a transcriptional –translational Auto-regulatory loop which leads to the molecular oscillations of our “core clock genes” at a specific cellular level. In the many mammalian and animal models, the master pacemaker is in the hypothalamus at the suprachiasmatic nucleus (SCN) that can regulate downstream oscillations in the peripheral tissues of the brain. The core clock genes are self- sustained and cell autonomous not only on the pace maker but also on the other dissociated cultured cells and peripheral tissues. Here we can review the general mechanisms involved in the clock genes that is responsible for the circadian rhythmicity in epileptic syndromes and these findings can elucidate the cell specific expression of the clock genes in different syndromes. In the recent past there has been considerable amount of progress in elucidating the molecular and cellular mechanisms that is involved in understand the core clock gene expression and the circadian rhythms effects on epileptic syndromes. However, there is very little understanding on how these two mechanisms interact to cause a core clock genes disruptions plays an important role. Recent studies in several animal models have shown the effects of time of the day on the neurophysiology and path-physiology in the epileptic syndrome. Together, these evidences from the past suggest that there can be a common mechanism underlying the circadian rhythmicity and epileptogenesis mechanism.

Putative rhythms in attentional switching can be explained by aperiodic temporal structure

The neural and perceptual effects of attention were traditionally assumed to be sustained over time, but recent work suggests that covert attention rhythmically switches between objects at 3–8 Hz. Here I use simulations to demonstrate that the analysis approaches commonly used to test for rhythmic oscillations generate false positives in the presence of aperiodic temporal structure. I then propose two alternative analyses that are better able to discriminate between periodic and aperiodic structure in time series. Finally, I apply these alternative analyses to published datasets and find no evidence for behavioural rhythms in attentional switching after accounting for aperiodic temporal structure. The techniques presented here will help clarify the periodic and aperiodic dynamics of perception and of cognition more broadly.

Distinct roles for two Caenorhabditis elegans acid-sensing ion channels in an ultradian clock.

Biological clocks are fundamental to an organism's health, controlling periodicity of behaviour and metabolism. Here, we identify two acid-sensing ion channels, with very different proton sensing properties, and describe their role in an ultradian clock, the defecation motor program (DMP) of the nematode Caenorhabditis elegans. An ACD-5-containing channel, on the apical membrane of the intestinal epithelium, is essential for maintenance of luminal acidity, and thus the rhythmic oscillations in lumen pH. In contrast, the second channel, composed of FLR-1, ACD-3 and/or DEL-5, located on the basolateral membrane, controls the intracellular Ca2+ wave and forms a core component of the master oscillator that controls the timing and rhythmicity of the DMP. flr-1 and acd-3/del-5 mutants show severe developmental and metabolic defects. We thus directly link the proton-sensing properties of these channels to their physiological roles in pH regulation and Ca2+ signalling, the generation of an ultradian oscillator, and its metabolic consequences.

INSP-05. Development of fast cortical rhythms in health and mental disease

Synchronization of neuronal activity in fast oscillatory rhythms is a commonly observed feature in the adult cerebral cortex. While its exact functions are still a matter of debate, oscillatory activity in gamma frequency range (20-100 Hz) has been proposed to organize neuronal ensembles and to shape information processing in cortical networks. Gamma activity emerges from reciprocal interactions between excitatory and inhibitory neurons. A fine-tuned balance between excitatory drive and inhibitory feedback is mandatory for circuit function underlying cognitive performance, whereas imbalance between excitation and inhibition and resulting gamma disruption have been proposed to cause cognitive disabilities in psychiatric disorders. Despite extensive investigation of gamma activity in adult brain, its development and function early in life are still poorly understood. The talk will highlight recent experimental findings that uncover the mechanisms and role of fast oscillatory activity throughout development. We will uncover how different neuronal populations interact to generate gamma oscillations. Moreover, we will show that these early oscillations are necessary for the adult cognitive abilities. On the flip side, poorer mnemonic and social abilities that have been characterized in several psychiatric disorders, such as schizophrenia and autism, might result from developmental miswiring of the brain. Our data support this hypothesis by demonstrating that weaker fast oscillatory rhythms, sparser connectivity and lower communication are present in the core circuit of cognitive processing, including the prefrontal cortex, hippocampus and entorhinal cortex, in mouse models of these disorders. Together, these findings highlight the relevance of fast cortical rhythms early in life for the adult brain function.

The central circadian regulator CCA1 functions in Glycine max during defense to a root pathogen, regulating the expression of genes acting in effector triggered immunity (ETI) and cell wall metabolism

Expression of the central circadian oscillator components CIRCADIAN CLOCK ASSOCIATED 1 (CCA1), TIMING OF CAB1 (TOC1), GIGANTEA (GI), and CONSTANS (CO) occurs in Glycine max root cells (syncytia) parasitized by the nematode Heterodera glycines while undergoing resistance, indicating a defense role. GmCCA1-1 relative transcript abundance (RTA) in roots experiencing overexpression (OE) or RNA interference (RNAi) is characterized by rhythmic oscillations, compared to a ribosomal protein gene (GmRPS21) control. A GmCCA1-1 RTA change, advancing by 12 h, exists in H. glycines-infected as compared to uninfected controls in wild-type, H. glycines-resistant, G. max[Peking/PI 548402]. The G. max[Peking/PI 548402] transgenic controls exhibit the RTA change by 4 h post infection (hpi), not consistently occurring in the H. glycines-susceptible G. max[Williams 82/PI 518671] until 56 hpi. GmCCA1-1 expression is observed to be reduced in H. glycines-infected GmCCA1-1-OE roots as compared to non-infected transgenic roots with no significant change observed among RNAi roots. The GmCCA1-1 expression in transgenic GmCCA1-1-OE roots remains higher than control and RNAi roots. Decreased GmCCA1-1 mRNA among infected roots shows the altered expression is targeted by H. glycines. Gene expression of proven defense genes including 9 different mitogen activated protein kinases (GmMAPKs), NON-RACE SPECIFIC DISEASE RESISTANCE 1 (GmNDR1-1), RPM1-INTERACTING PROTEIN 4 (GmRIN4-4), and the secreted xyloglucan endotransglycosylase/hydrolase 43 (GmXTH43) in GmCCA1-1-OE and GmCCA1-1-RNAi roots, compared to controls, reveal a significant role of GmCCA1-1 expression in roots undergoing defense to H. glycines parasitism. The observation that GmCCA1-1 regulates GmXTH43 expression links the central circadian oscillator to the functionality of the secretion system.