Delta Activity Research Articles

SARS-CoV-2 clade dynamics and their associations with hospitalisations during the first two years of the COVID-19 pandemic.

The COVID-19 pandemic was characterised by rapid waves of disease, carried by the emergence of new and more infectious SARS-CoV-2 virus variants. How the pandemic unfolded in various locations during its first two years has yet to be sufficiently covered. To this end, here we are looking at the circulating SARS-CoV-2 variants, their diversity, and hospitalisation rates in Estonia in the period from March 2000 to March 2022. We sequenced a total of 27,550 SARS-CoV-2 samples in Estonia between March 2020 and March 2022. High-quality sequences were genotyped and assigned to Nextstrain clades and Pango lineages. We used regression analysis to determine the dynamics of lineage diversity and the probability of clade-specific hospitalisation stratified by age and sex. We successfully sequenced a total of 25,375 SARS-CoV-2 genomes (or 92%), identifying 19 Nextstrain clades and 199 Pango lineages. In 2020 the most prevalent clades were 20B and 20A. The various subsequent waves of infection were driven by 20I (Alpha), 21J (Delta) and Omicron clades 21K and 21L. Lineage diversity via the Shannon index was at its highest during the Delta wave. About 3% of sequenced SARS-CoV-2 samples came from hospitalised individuals. Hospitalisation increased markedly with age in the over-forties, and was negligible in the under-forties. Vaccination decreased the odds of hospitalisation in over-forties. The effect of vaccination on hospitalisation rates was strongly dependent upon age but was clade-independent. People who were infected with Omicron clades had a lower hospitalisation likelihood in age groups of forty and over than was the case with pre-Omicron clades regardless of vaccination status. COVID-19 disease waves in Estonia were driven by the Alpha, Delta, and Omicron clades. Omicron clades were associated with a substantially lower hospitalisation probability than pre-Omicron clades. The protective effect of vaccination in reducing hospitalisation likelihood was independent of the involved clade.

High SARS-CoV-2 incidence and asymptomatic fraction during Delta and Omicron BA.1 waves in The Gambia

Little is known about SARS-CoV-2 infection risk in African countries with high levels of infection-driven immunity and low vaccine coverage. We conducted a prospective cohort study of 349 participants from 52 households in The Gambia between March 2021 and June 2022, with routine weekly SARS-CoV-2 RT-PCR and 6-monthly SARS-CoV-2 serology. Attack rates of 45% and 57% were seen during Delta and Omicron BA.1 waves respectively. Eighty-four percent of RT-PCR-positive infections were asymptomatic. Children under 5-years had a lower incidence of infection than 18-49-year-olds. One prior SARS-CoV-2 infection reduced infection risk during the Delta wave only, with immunity from ≥2 prior infections required to reduce the risk of infection with early Omicron lineage viruses. In an African population with high levels of infection-driven immunity and low vaccine coverage, we find high attack rates during SARS-CoV-2 waves, with a high proportion of asymptomatic infections and young children remaining relatively protected from infection.

Involvement of prelimbic cortex neurons and related circuits in the acquisition of a cooperative learning by pairs of rats

AbstractSocial behaviors such as cooperation are crucial for mammals. A deeper knowledge of the neuronal mechanisms underlying cooperation can be beneficial for people suffering from pathologies with impaired social behavior. Our aim was to study the brain activity when two animals synchronize their behavior to obtain a mutual reinforcement. In a previous work, we showed that the activity of the prelimbic cortex (PrL) was enhanced during cooperation in rats, especially in the ones leading most cooperative trials (leader rats). In this study, we investigated the specific cells in the PrL contributing to cooperative behaviors. To this end, we collected rats’ brains at key moments of the learning process to analyze the levels of c-FOS expression in the main cellular groups of the PrL. Leader rats showed increased c-FOS activity in cells expressing D1 receptors during cooperation. Besides, we analyzed the levels of anxiety, dominance, and locomotor behavior, finding that leader rats are in general less anxious and less dominant than followers. We also recorded local field potentials (LFPs) from the PrL, the nucleus accumbens septi (NAc), and the basolateral amygdala (BLA). A spectral analysis showed that delta activity in PrL and NAc increased when rats cooperated, while BLA activity in delta and theta bands decreased considerably during cooperation. The PrL and NAc also increased their connectivity in the high theta band during cooperation. Thus, the present work identifies the specific PrL cell types engaged in this behavior, as well as the way this information is propagated to selected downstream brain regions (BLA, NAc).

Characteristics of Right-Sided Accessory Pathways Associated With Right Cardiac Veins.

The anatomy of myocardial fibers around the right cardiac veins (RCVs) and their roles in accessory pathways (APs) are rarely reported. Six RCV-APs were identified from 566 patients with right-sided APs. Mapping of retrograde atrial activation was performed using CARTO 3 system under orthodromic tachycardia or right ventricular pacing. Venography of RCVs was acquired at the earliest retrograde atrial activation. Patients enrolled had a median age of 30 (11-51) years, 5 of them were male. Venography of RCVs could be classified into 3 distinct patterns based on the identified ventricular branches, right marginal vein only (type I; n=3), both right marginal vein and anterior cardiac veins (type II; n=2), and anterior cardiac vein only (type III; n=1). Patients with type I venography had rS QRS pattern in lead V1, negative delta wave in lead III and negative or isoelectric delta wave in lead aVF. However, patients with type II and III venography had QS QRS patterns in lead V1 and variable patterns of delta wave in inferior leads. Earliest retrograde atrial activation was found at a median of 16.75 (14.60-20.00) mm away from the tricuspid annulus, all with A larger than V. At the earliest retrograde atrial activation, far-field ventricular electrogram was found 30 ms later than QRS onset in 1 patient under sinus rhythm. AP conduction was eliminated by mechanical pressure in 2 and by radiofrequency ablation in 4 at the ostium of the veins colocalizing with the earliest retrograde activation of the right atrium. No recurrence observed during 36 (10-60) months follow-up. The RCV-AP is a rare form of right-sided APs characterized by atrial insertions distant from the annulus. ECG-speculated ventricular insertion sites conformed to the location of identified RCVs.

Investigating the impact of Mahā Mantra chanting on anxiety and depression : An EEG Rhythm Analysis Approach

Hare kṛṣṇa hare kṛṣṇa kṛṣṇa kṛṣṇa hare hare hare rāma hare rāma rāma rāma hare hare is the Mahā Mantra (MM). The Mantra is believed to be the sacred mantra from the ancient times. In the current research, an attempt has been made to study the brain dynamics of oscillatory changes after MM chanting. The mantra chanting produces a state of mind that has a positive effect on the individual’s brain. The electroencephalogram (EEG) signals are asynchronous in nature and record the brain's present state. In this study, forty individuals were assigned randomly into two (pre &post) groups,(n=20) with equal ratio of male and female and having mean age 25.5 yr. EEG signal was recorded in eyes closed condition both prior as well as after the MM chanting. The rhythms (Delta, theta, alpha, beta, and gamma) were extracted from the recorded EEG signals. To match the behavioural changes in the nature of the EEG, the power of the rhythm was computed and compared. According to the study, chanting MM leads to increase in alpha relative power in the central and parietal regions of the brain, which indicates that the brain has been refreshed and relieved. The study showed generous production of alpha, theta and delta waves which has been found in the study to be associated with the secretion of hormones or neurotransmitters causing dilation of blood vessels. As per literature it has been found that increase in relative alpha band power is associated with the secretion of hormones or neurotransmitters causing dilation of blood vessels which is further associated with the improvement in the mental well-being and feeling relaxed and releived, thus leading to decrease in anxiety and depression. The current research study proves the impact of the MM chanting leads to mental alleviation and mental well-being to a great extent.

Frontal delta and theta power reflect strategy changes during human spatial memory retrieval in a virtual water maze task: an exploratory analysis

Brain oscillations in humans play a role in a wide range of cognitive processes, including navigation and memory. The oscillatory dynamics contributing to successful spatial memory recall in humans are not well-understood. To investigate specific oscillatory frequency bands during the recall process in human navigation, we recorded electroencephalographic (EEG) activity during a recall trial in healthy young adults (n = 15) following the learning of a goal location in a Virtual Water Maze task. We compared this to the activity during the same trial length, in a group of participants who did not learn a target location and navigated freely but were time-matched to the learning group (non-learning, n = 15). We compared relative power in Delta (2–4 Hz), Theta (5–7 Hz), Alpha (8–12 Hz), Beta (15–29 Hz), and Gamma (30–40 Hz) bands across the scalp. We found that delta and theta activity were greater during recall in our learning group, as opposed to our non-learning group. We also demonstrated clear suppression in the alpha band at posterior sites during memory-guided navigation compared to our non-learning group. Additionally, when goal-directed navigation switches to focused searching behavior, power becomes greater at the frontal region; with increases in the delta and theta bands reflecting this strategy change. There was also greater beta and gamma activity at posterior sites in our learning group. We discuss the results further in terms of the possible roles and functions of these oscillations during human navigation and hope this exploratory analysis can provide hypotheses for future spatial navigation and memory work.

COVID-19 Aftereffects (Long COVID) Associated with Wuhan, Delta, and Omicron Variants Reported in Japanese Hospitals

COVID-19 Aftereffects (Long COVID) Associated with Wuhan, Delta, and Omicron Variants Reported in Japanese Hospitals

Assessment of Effects of Carbon Dioxide Exposure on Sleep Stability in Insomnia Using the Envelope Analysis

Objectives: Insomnia is a common sleep disorder, and various strategies have been explored for its treatment. One of the methods involves the administration of carbon dioxide (CO<sub>2</sub>) at bedtime, as the CO<sub>2</sub> increment exerts a sedative effect on the central nervous system. We aimed to assess the effect of CO<sub>2</sub> on sleep quality in patients with insomnia using the coefficient of variation of the envelope (CVE) analysis, a novel analytical method. Methods: In this randomized, double-blind, sham-controlled crossover trial, 24 adults with sleeping difficulties underwent level 1 polysomnography. Two interventions involved exposure to either 2% low-concentration CO<sub>2</sub> gas or room air. CVE analysis was performed to assess the stability of the delta band. Morphological variations in delta waves can be quantitatively monitored using the envelope analysis, which assesses the effect of manipulations on sleep that may otherwise elude detection. Results: Exposure to CO<sub>2</sub> improved the total sleep time (TST) (<i>p</i>=0.010) and total arousal index (TAI) (<i>p</i>=0.011). The CVE analysis showed a distinct distribution between the experimental and sham-controlled groups. Moreover, correlations between the TST and CVE (r=0.41) and those between the TAI and CVE (r=0.40) were observed. Conclusions: This study is the first to evaluate the effects of CO<sub>2</sub> exposure on sleep stability in patients with insomnia. The CVE analysis implies the possibility of sleep stabilization by CO<sub>2</sub> administration and suggests a link between enhanced sleep maintenance and sleep stability.

Retraction: A comparison of Delta and Omicron waves of COVID-19 pandemic: An observation from a tertiary care center from North India

Retraction: A comparison of Delta and Omicron waves of COVID-19 pandemic: An observation from a tertiary care center from North India

Significance of thalamic hyperperfusion patterns in computed tomography perfusion in patients with nonconvulsive status epilepticus: possible utility in predicting antiseizure medication resistance

Background: This study aimed to determine the characteristics of computed tomography perfusion (CTP) patterns and their utility in predicting antiseizure medication (ASM) resistance in patients with nonconvulsive status epilepticus (NCSE).Methods: We retrospectively reviewed patients diagnosed with NCSE at Inje University Haeundae Paik Hospital Epilepsy Center between March 2015 and March 2022. CTP patterns were analyzed for those patients. A hyperperfusion pattern (HPP) in CTP was defined as a region of both increased cerebral blood flow and cerebral blood volume that did not necessarily follow the vascular territories. The primary endpoint was the responses to ASMs according to CTP patterns.Results: Fourteen (74%) of the 19 included patients met the criteria for definite NCSE, with the remaining 26% showing nonepileptiform activities with fluctuating quasirhythmic delta activities at >0.5 Hz on electroencephalogram. Three of the four patients who had HPPs with thalamic involvement were refractory to ASMs, whereas all eight patients who had HPPs without thalamic involvement were responsive to ASMs (<i>p</i> = 0.018). Although HPPs themselves were not associated with ASM responses, HPPs with thalamic involvement were associated with resistance to ASMs.Conclusions: HPP with thalamic involvement in CTP might be associated with ASM resistance. Therefore, CTP may be useful for predicting ASM resistance in NCSE patients.

Recurrent Orthodromic SVT AVRT with Multiple Accessory Pathway in WPW Syndrome: Ablate All or Not?

Background: Patients diagnosed with Wolff-Parkinson-White syndrome (WPW) have a relatively low, nevertheless persistent risk of unexpected mortality. However, this risk can be effectively mitigated by applying radiofrequency catheter ablation targeting the accessory pathway. It is difficult to accurately study predictors because only a minority of patients develop potentially malignant arrhythmias (MA) or passed away, despite essential risk variables being relatively well-known.1 This study aimed to describe ablation in WPW syndrome. Case presentation: A 16-year-old male presents with symptoms characterized by palpitations during intense physical exertion, followed by chest pain episodes. The physical examination, CXR, laboratorium, and echocardiography were all within the normal range; his ECG showed shortened PR interval and a delta wave with a positive delta wave at V1 and mostly positive at the inferior lead. He also has recorded ECG when the patient has a tachycardia event with SVT AVRT orthodromic pattern. He underwent EP Study and had several accessory pathways at the posteroseptal mitral annulus and anteroseptal tricuspid. The decision was made to perform ablation on the posteroseptal accessory pathway located at the mitral annulus. An electrophysiology (EP) investigation was conducted at the anteroseptal tricuspid annulus, which did not induce tachyarrhythmia. Conclusion: Wolff-Parkinson-White syndrome is a congenital cardiac pathway formation, with not all accessory pathways causing tachyarrhythmias. Ablation therapy is necessary for patients with multiple pathways, with pathways with an ERP less than 250 being the only option. Keyword: Ablation, Multiple Accessories Pathway, SVT AVRT Orthodromic, WPW Syndrome.

Angiopoietins as Predictor Indexes in COVID-19 Patients in Delta and Omicron Waves

This study aimed to explore the correlation between Angiopoietin-1 (Ang-1) and Angiopoietin-2 (Ang-2) concentrations and the Angiopoietin-2/Angiopoietin-1 ratio (Ang-2/Ang-1) with clinical outcomes, potentially serving as disease severity and survival biomarkers. A study at AHEPA University Hospital involved 90 Coronavirus Disease 2019 (COVID-19) adult patients, 30 hospitalized intensive care units (ICU), 30 inward units (non-ICU), and 30 asymptomatic non-hospitalized individuals as controls. Estimated endothelial dysfunction markers related to angiogenesis were measured. There was a statistically significant difference only between outpatient and hospitalized patients (non-ICU–ICU groups) for the Ang-1 and Ang-2 indices. The Ang-2/Ang-1 ratio has differed significantly among the individual patient groups. An ROC analysis was conducted to find an optimal threshold for distinguishing between (outpatients–non-ICU) and (non-ICU–ICU) groups. It was based on Youden’s index of 0.1122 and 0.3825, respectively. The Ang-1, Ang-2 levels, and Ang-2/Ang-1 ratio were analyzed as severity indicators in COVID-19 patients. The Ang-2/Ang-1 ratio demonstrated better prognostic and diagnostic utility than individual biomarker levels. Monitoring the Ang-2/Ang-1 ratio can identify COVID-19 patients at risk and assist clinicians in tailoring treatment strategies to improve outcomes.

The impact of the COVID-19 pandemic, and care home closures on timing of mortality in residents of English LTCFs

Background In the UK, mortality incidence of residents in long-term care facilities (LTCFs) was high during the first two waves of the COVID-19 pandemic. Prior to the pandemic, mortality risk was greater amongst new LTCFs admissions compared to longer term residents. Following the re-opening of these facilities to new residents after the second wave of the pandemic, we hypothesised that this difference would be more pronounced. We aimed to establish whether this occurred by comparing mortality risk in new admissions with existing residents. Methods Data were accessed from the VIVALDI study, a prospective cohort study set up to investigate COVID-19 in English LTCFs. Residents aged over 65 were included and analysis performed over the Delta (16th May 2021-19th December 2021) and Omicron (19th December 2021-31st March 2022) waves of the pandemic. Classification into new and existing residents was based on presence in the LTCF before or after 24th April 2021. Mixed effects Cox regression models were used, with separate hazard ratios associated for existing vs new residents estimated for each calendar month. Results 11,532 residents were observed during the Delta wave and 9,801 during the Omicron wave. Mortality hazard ratios for existing care home residents compared to new care home residents stabilised after September 2021, following a period of reduced risk between May (HR: 0.23 95% CI: 0.11-0.47) and August (HR: 0.37, CI:0.29-0.47) 2021. No mortality displacement was observed in the Omicron wave. Conclusions Mortality rates amongst existing residents were lower than anticipated between May and August 2021 but increased and stabilised by September 2021, providing evidence for mortality displacement within this population. Improved monitoring of infection outcomes for LTCF residents that consider time since admission would help improve our understanding of the dynamics and composition of LTCF populations in non-pandemic periods.

Discovery of recessive effect of human polymerase δ proofreading deficiency through mutational analysis of POLD1-mutated normal and cancer cells.

Constitutional heterozygous pathogenic variants in the exonuclease domain of POLE and POLD1, which affect the proofreading activity of thecorresponding polymerases, cause a cancer predisposition syndrome characterized by increased risk of gastrointestinal polyposis, colorectal cancer, endometrial cancer and other tumor types. The generally accepted explanation for the connection between the disruption of the proofreading activity of polymerases epsilon and delta and cancer development is through an increase in the somatic mutation rate. Here we studied an extended family with multiple members heterozygous for the pathogenic POLD1 variant c.1421T>C p.(Leu474Pro), which segregates with the polyposis and cancer phenotypes. Through the analysis of mutational patterns of patient-derived fibroblasts colonies and de novo mutations obtained by parent-offspring comparisons, we concluded that heterozygous POLD1 L474P just subtly increases the somatic and germline mutation burden. In contrast, tumors developed in individuals with a heterozygous mutation inthe exonuclease domain of POLD1, including L474P, have an extremely high mutation rate (>100 mut/Mb) associated with signature SBS10d. We solved this contradiction through the observation that tumorigenesis involves somatic inactivation of the wildtype POLD1 allele. These results imply that exonuclease deficiency of polymerase delta has a recessive effect on mutation rate.

Long-term monitoring of SARS-CoV-2 seroprevalence and variants in Ethiopia provides prediction for immunity and cross-immunity

Under-reporting of COVID-19 and the limited information about circulating SARS-CoV-2 variants remain major challenges for many African countries. We analyzed SARS-CoV-2 infection dynamics in Addis Ababa and Jimma, Ethiopia, focusing on reinfection, immunity, and vaccination effects. We conducted an antibody serology study spanning August 2020 to July 2022 with five rounds of data collection across a population of 4723, sequenced PCR-test positive samples, used available test positivity rates, and constructed two mathematical models integrating this data. A multivariant model explores variant dynamics identifying wildtype, alpha, delta, and omicron BA.4/5 as key variants in the study population, and cross-immunity between variants, revealing risk reductions between 24% and 69%. An antibody-level model predicts slow decay leading to sustained high antibody levels. Retrospectively, increased early vaccination might have substantially reduced infections during the delta and omicron waves in the considered group of individuals, though further vaccination now seems less impactful.

Outcome measures of brainwave entrainment using delta wave stimulation in individuals with tinnitus having normal hearing sensitivity.

The current study aimed to evaluate the efficacy of delta frequency binaural beats stimulation in treatment of individuals with tinnitus having normal hearing sensitivity. Twenty-four individuals who reported bothersome tinnitus in the presence of clinically normal hearing were grouped into two (I and II). The group was provided with delta frequency binaural beats and II was provided with white noise stimulation (both of 20min duration) for 30days. Post 30days, the re-assessment of tinnitus handicap, depression, anxiety, and quality of life parameters were performed and compared with that of pre-treatment scores. A considerable reduction of tinnitus handicap scores, depression and anxiety levels were observed for both the groups, except for the quality-of-life parameters. However, few of the participants showed limited or negligible improvement post-treatment. On comparison of reduction of scores observed across the groups, there was a higher reduction of scores observed for group I when compared to group II. The current study was an initial attempt to study the efficacy of binaural beats in treatment of individuals with tinnitus having normal hearing. Apart from a few individuals, the delta wave stimulation acted as a helpful tool in improving tinnitus borne distress symptoms in such patients with normal hearing.The results of the present study put forward the scope of adapting binaural beats stimulation for the treatment of individuals presenting with tinnitus having normal hearing sensitivity. This technique could be adopted into clinical practice after extensive research involving an extended treatment duration on a larger population.

Machine learning reveals differential effects of depression and anxiety on reward and punishment processing.

Recent studies suggest that depression and anxiety are associated with unique aspects of EEG responses to reward and punishment, respectively; also, abnormal responses to punishment in depressed individuals are related to anxiety, the symptoms of which are comorbid with depression. In a non-clinical sample, we aimed to investigate the relationships between reward processing and anxiety, between punishment processing and anxiety, between reward processing and depression, and between punishment processing and depression. Towards this aim, we separated feedback-related brain activity into delta and theta bands to isolate activity that indexes functionally distinct processes. Based on the delta/theta frequency and feedback valence, we then used machine learning (ML) to classify individuals with high severity of depressive symptoms and individuals with high severity of anxiety symptoms versus controls. The significant difference between the depression and control groups was driven mainly by delta activity; there were no differences between reward- and punishment-theta activities. The high severity of anxiety symptoms was marginally more strongly associated with the punishment- than the reward-theta feedback processing. The findings provide new insights into the differences in the impacts of anxiety and depression on reward and punishment processing; our study shows the utility of ML in testing brain-behavior hypotheses and emphasizes the joint effect of theta-RewP/FRN and delta frequency on feedback-related brain activity.

Creutzfeldt-Jakob disease in a man surviving COVID-19: disentangling a casual or causal association by neuropathology.

Literature reporting the onset of Creutzfeldt-Jakob disease (CJD) immediately after COVID-19 infection has strengthened a possible causal link between infection and neurodegeneration. Here, we report a novel case undergoing detailed neuropathological assessment. Two months after he had contracted SARS-CoV-2 infection, a 54-year-old man manifested a subacute onset of ataxia, headache, anosmia, and hallucinations, followed by rapidly progressive cognitive decline. Electroencephalography documented unspecific slowing with periodic polyphasic delta waves. Brain MRI showed hyperintensities of basal ganglia and thalami on DWI/FLAIR. CSF tested positive for the 14-3-3 protein, and prion seeding activity was demonstrated by the real-time quaking-induced conversion assay. The patient died 2months after the neurologic onset. The neuropathological examination confirmed the diagnosis of CJD and ruled out COVID-19-related encephalitis. To disentangle the link between COVID-19 infection and CJD, neuropathology is essential determining the extent of changes related to both conditions. In our patient, we did not find any specific abnormality related to COVID-19. Our conclusion is in line with the current worldwide epidemiological data that do not show an increase in CJD cases since the beginning of the COVID-19 pandemic.

Neuroligin-2 shapes individual slow waves during slow-wave sleep and the response to sleep deprivation in mice

BackgroundSleep disturbances are a common comorbidity to most neurodevelopmental disorders and tend to worsen disease symptomatology. It is thus crucial to understand mechanisms underlying sleep disturbances to improve patients’ quality of life. Neuroligin-2 (NLGN2) is a synaptic adhesion protein regulating GABAergic transmission. It has been linked to autism spectrum disorders and schizophrenia in humans, and deregulations of its expression were shown to cause epileptic-like hypersynchronized cerebral activity in rodents. Importantly, the absence of Nlgn2 (knockout: KO) was previously shown to alter sleep-wake duration and quality in mice, notably increasing slow-wave sleep (SWS) delta activity (1–4 Hz) and altering its 24-h dynamics. This type of brain oscillation is involved in memory consolidation, and is also a marker of homeostatic sleep pressure. Sleep deprivation (SD) is notably known to impair cognition and the physiological response to sleep loss involves GABAergic transmission.MethodsUsing electrocorticographic (ECoG) recordings, we here first aimed to verify how individual slow wave (SW; 0.5-4 Hz) density and properties (e.g., amplitude, slope, frequency) contribute to the higher SWS delta activity and altered 24-h dynamics observed in Nlgn2 KO mice. We further investigated the response of these animals to SD. Finally, we tested whether sleep loss affects the gene expression of Nlgn2 and related GABAergic transcripts in the cerebral cortex of wild-type mice using RNA sequencing.ResultsOur results show that Nlgn2 KO mice have both greater SW amplitude and density, and that SW density is the main property contributing to the altered 24-h dynamics. We also found the absence of Nlgn2 to accelerate paradoxical sleep recovery following SD, together with profound alterations in ECoG activity across vigilance states. Sleep loss, however, did not modify the 24-h distribution of the hypersynchronized ECoG events observed in these mice. Finally, RNA sequencing confirmed an overall decrease in cortical expression of Nlgn2 and related GABAergic transcripts following SD in wild-type mice.ConclusionsThis work brings further insight into potential mechanisms of sleep duration and quality deregulation in neurodevelopmental disorders, notably involving NLGN2 and GABAergic neurotransmission.

Study on the Effect of Dalbergia pinnata (Lour.) Prain Essential Oil on Electroencephalography upon Stimulation with Different Auditory Effects.

Dalbergia pinnata (Lour.) Prain (D. pinnata) is a valuable medicinal plant, and its volatile parts have a pleasant aroma. In recent years, there have been a large number of studies investigating the effect of aroma on human performance. However, the effect of the aroma of D. pinnata on human psychophysiological activity has not been reported. Few reports have been made about the effects of aroma and sound on human electroencephalographic (EEG) activity. This study aimed to investigate the effects of D. pinnata essential oil in EEG activity response to various auditory stimuli. In the EEG study, 30 healthy volunteers (15 men and 15 women) participated. The electroencephalogram changes of participants during the essential oil (EO) of D. pinnata inhalation under white noise, pink noise and traffic noise stimulations were recorded. EEG data from 30 electrodes placed on the scalp were analyzed according to the international 10-20 system. The EO of D. pinnata had various effects on the brain when subjected to different auditory stimuli. In EEG studies, delta waves increased by 20% in noiseless and white noise environments, a change that may aid sleep and relaxation. In the presence of pink noise and traffic noise, alpha and delta wave activity (frontal pole and frontal lobe) increased markedly when inhaling the EO of D. pinnata, a change that may help reduce anxiety. When inhaling the EO of D. pinnata with different auditory stimuli, women are more likely to relax and get sleepy compared to men.