Modulation of interactions among neurons can manifest as dramatic changes in the state of population dynamics in cerebral cortex. How such transitions in cortical state impact the information processing performed by cortical circuits is not clear. Here we performed experiments and computational modeling to determine how somatosensory dynamic range depends on cortical state. We used microelectrode arrays to record ongoing and whisker stimulus-evoked population spiking activity in somatosensory cortex of urethane anesthetized rats. We observed a continuum of different cortical states; at one extreme population activity exhibited small scale variability and was weakly correlated, the other extreme had large scale fluctuations and strong correlations. In experiments, shifts along the continuum often occurred naturally, without direct manipulation. In addition, in both the experiment and the model we directly tuned the cortical state by manipulating inhibitory synaptic interactions. Our principal finding was that somatosensory dynamic range was maximized in a specific cortical state, called criticality, near the tipping point midway between the ends of the continuum. The optimal cortical state was uniquely characterized by scale-free ongoing population dynamics and moderate correlations, in line with theoretical predictions about criticality. However, to reproduce our experimental findings, we found that existing theory required modifications which account for activity-dependent depression. In conclusion, our experiments indicate that in vivo sensory dynamic range is maximized near criticality and our model revealed an unanticipated role for activity-dependent depression in this basic principle of cortical function.
The Pediatric Cardiac Genomics Consortium (PCGC) designed the Congenital Heart Disease Genetic Network Study to provide phenotype and genotype data for a large congenital heart defects (CHDs) cohort. This article describes the PCGC cohort, overall and by major types of CHDs (e.g., conotruncal defects) and subtypes of conotrucal heart defects (e.g., tetralogy of Fallot) and left ventricular outflow tract obstructions (e.g., hypoplastic left heart syndrome). Cases with CHDs were recruited through ten sites, 2010–2014. Information on cases (N = 9,727) and their parents was collected through interviews and medical record abstraction. Four case characteristics, eleven parental characteristics, and thirteen parent-reported neurodevelopment outcomes were summarized using counts and frequencies and compared across CHD types and subtypes. Eleven percent of cases had a genetic diagnosis. Among cases without a genetic diagnosis, the majority had conotruncal heart defects (40%) or left ventricular outflow tract obstruction (21%). Across CHD types, there were significant differences (p<0.05) in the distribution of all four case characteristics (e.g., sex), four parental characteristics (e.g., maternal pregestational diabetes), and five neurodevelopmental outcomes (e.g., learning disabilities). Several characteristics (e.g., sex) were also significantly different across CHD subtypes. The PCGC cohort is one of the largest CHD cohorts available for the study of genetic determinants of risk and outcomes. The majority of cases do not have a genetic diagnosis. This description of the PCGC cohort, including differences across CHD types and subtypes, provides a reference work for investigators who are interested in collaborating with or using publically available resources from the PCGC.
Maternal diabetes is associated with congenital heart defects (CHDs) as a group, but few studies have assessed risk for specific CHD phenotypes. We analyzed these relationships using data from the Texas Birth Defects Registry and statewide vital records for deliveries taking place in 1999-2009 (n = 48,249 cases). We used Poisson regression to calculate prevalence ratios for the associations between maternal diabetes (pregestational or gestational) and each CHD phenotype, adjusting for potential confounders. Analyses were repeated by type of diabetes. To address the potential for misclassification bias, we performed logistic regression, using malformed controls. We also conducted meta-analyses, combining our estimates of the association between pregestational diabetes and each CHD phenotype with previous estimates. The prevalence of every CHD phenotype was greater among women with pregestational diabetes than among nondiabetic women. Most of these differences were statistically significant (adjusted prevalence ratios = 2.47-13.20). Associations were slightly attenuated for many CHD phenotypes among women with gestational diabetes. The observed associations did not appear to be the result of misclassification bias. In our meta-analysis, pregestational diabetes was significantly associated with each CHD phenotype. These findings contribute to a better understanding of the teratogenic effects of maternal diabetes and improved counseling for risk of specific CHD phenotypes.
Key Points Question Is living in a neighborhood with a high concentration of household and population features characteristic of lower socioeconomic status (ie, a neighborhood with high deprivation) associated with epigenetic age acceleration across first- and second-generation clock metrics? Findings This cross-sectional study comprised 2630 women who had a sister with breast cancer but had not had breast cancer themselves. Those living in areas with the greatest compared with least neighborhood deprivation had higher epigenetic age acceleration estimated by Hannum, PhenoAge, and GrimAge clocks but not the Horvath clock. Meaning The results of this study suggest that residing in a neighborhood with a higher deprivation index appears to be reflected by methylation-based markers of aging.
Epigenome-wide studies of methylation in children support a role for epigenetic mechanisms in asthma. Studies in adults are rare, and few have examined non-atopic asthma. We conducted the largest epigenome-wide association study of blood DNA methylation in adults in relation to non-atopic and atopic asthma.We measured DNA methylation in blood using the Illumina MethylationEPIC array among 2286 participants in a case-control study of current adult asthma nested within a U.S. agricultural cohort. Atopy was defined by serum specific immunoglobulin E. Participants were categorised as atopy without asthma (n=185), non-atopic asthma (n=673), atopic asthma (n=271), or a reference group of neither atopy nor asthma (n=1157). Analyses were conducted using logistic regression.No associations were observed with atopy without asthma. Numerous CpGs were differentially methylated in non-atopic asthma (8 at family-wise error rate [FWER] p<9×10−8; 524 at False Discovery Rate [FDR]<0.05) and implicated 382 novel genes. More CpGs were identified in atopic asthma (181 at FWER; 1086 at FDR) and implicated 569 novel genes. 104 FDR CpGs overlapped. 35% of CpGs in non-atopic asthma and 91% in atopic asthma replicated in studies of whole blood, eosinophils, airway epithelium, or nasal epithelium. Implicated genes were enriched in pathways related to the nervous system or inflammation.We identified numerous, distinct differentially methylated CpGs in non-atopic and atopic asthma. Many CpGs from blood replicated in asthma-relevant tissues. These circulating biomarkers reflect risk and sequelae of disease and implicate novel genes associated with non-atopic and atopic asthma.
Background: Pesticide exposure is associated with many long-term health outcomes; the potential underlying mechanisms are not well established for most associations. Epigenetic modifications, such as DNA methylation, may contribute. Individual pesticides may be associated with specific DNA methylation patterns but no epigenome-wide association study (EWAS) has evaluated methylation in relation to individual pesticides. Objectives: We conducted an EWAS of DNA methylation in relation to several pesticide active ingredients. Methods: The Agricultural Lung Health Study is a case–control study of asthma, nested within the Agricultural Health Study. We analyzed blood DNA methylation measured using Illumina’s EPIC array in 1,170 male farmers of European ancestry. For pesticides still on the market at blood collection (2009–2013), we evaluated nine active ingredients for which at least 30 participants reported past and current (within the last 12 months) use, as well as seven banned organochlorines with at least 30 participants reporting past use. We used robust linear regression to compare methylation at individual C-phosphate-G sites (CpGs) among users of a specific pesticide to never users. Results: Using family-wise error rate ( ) or false-discovery rate ( ), we identified 162 differentially methylated CpGs across 8 of 9 currently marketed active ingredients (acetochlor, atrazine, dicamba, glyphosate, malathion, metolachlor, mesotrione, and picloram) and one banned organochlorine (heptachlor). Differentially methylated CpGs were unique to each active ingredient, and a dose–response relationship with lifetime days of use was observed for most. Significant CpGs were enriched for transcription motifs and 28% of CpGs were associated with whole blood cis -gene expression, supporting functional effects of findings. We corroborated a previously reported association between dichlorodiphenyltrichloroethane (banned in the United States in 1972) and epigenetic age acceleration. Discussion: We identified differential methylation for several active ingredients in male farmers of European ancestry. These may serve as biomarkers of chronic exposure and could inform mechanisms of long-term health outcomes from pesticide exposure. https://doi.org/10.1289/EHP8928
Hypospadias is one of the most common birth defects in male infants. Maternal hypertension is a suspected risk factor; however, few previous studies have addressed the possibility of reporting bias, and several previous studies have not accounted for hypospadias severity. We analyzed data from the Texas Birth Defects Registry for 10,924 nonsyndromic cases and statewide vital records for deliveries during 1999-2009, using Poisson regression. After adjustment for potential confounders, hypospadias was associated with maternal hypertension (adjusted prevalence ratio: 1.5, 95% confidence interval: 1.4-1.7). Similar associations were observed with gestational and pregestational hypertension, including separate analyses restricted to the subset of cases with severe (second- or third-degree) hypospadias. All of these associations were also similar among the subset of cases with isolated hypospadias (without additional birth defects). To evaluate the potential for bias due to potential hypertension misclassification, we repeated our analyses using logistic regression, comparing the cases to controls with other birth defects. In these analyses, the associations with gestational hypertension were similar, but adjusted associations with pregestational hypertension were no longer observed. Our findings support an association between gestational hypertension and hypospadias in offspring, but also suggest that previously observed associations with pregestational hypertension may have been inflated due to differential misclassification of hypertension (e.g., reporting bias). As gestational hypertension is recognized after hypospadias development, more research is needed to determine if this association reflects an increase in gestational hypertension risk secondary to hypospadias or if both conditions have shared risk factors (e.g., precursors of gestational hypertension). © 2016 Wiley Periodicals, Inc.
D iphtheria is a serious childhood disease with a high mortality rate (1). After a diphtheria-tetanus-pertussis vaccine (DTP) was introduced in the early 20th century, the number of cases dramatically decreased. Incidence reached a low of 4,333 cases in 2006, but more recently, the number of reported cases has increased, with incidence reaching 16,648 cases in 2018 (2). In 1981, Vietnam introduced a vaccination program in which participants received 3 primary doses of DTP (DTP3) vaccine; in 2011, a booster shot (DTP4) to be given 18 months after the initial doses was added (3). Although diphtheria cases had become sporadic by 2010, beginning in 2013, outbreaks occurred in the western and central highland areas of Vietnam, which prompted our study (4). The Study During June 2015-April 2018, the Pasteur Institute in Nha Trang, Vietnam, and the provincial health authority investigated 46 cases involving patients with suspected diphtheria, 8 of whom died, and 49 asymptomatic contacts in the provinces of Quang Nam and Quang Ngai in the central highlands region of Vietnam (Figure 1). We used standard case investigation forms to collect demographic and clinical information. We collected throat swab specimens from 93 patients and contacts but were unable to collect samples from 2 patients who had died. No cutaneous diphtheria was reported. We used sheep blood agar and tellurite medium cultures to identify Corynebacterium diphtheriae and extracted DNA with a QIAGEN DNA Mini Kit (QIA-GEN, https://www.qiagen.com), following a standard protocol. We used 2 sets of primers, Tox1/Tox2 and Dipht6F/Dipht6R, for PCR testing (5). The Elek test for diphtheria is not available in Vietnam. Laboratory testing confirmed diphtheria in 22 of 46 suspected cases: 17 patients, including 4 who died, tested positive in both culture and PCR tests, whereas 5 patients, including 1 who died, tested positive only
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