Circuits in the cerebral cortex consist of thousands of neurons connected by millions of synapses. A precise understanding of these local networks requires relating circuit activity with the ...underlying network structure. For pyramidal cells in superficial mouse visual cortex (V1), a consensus is emerging that neurons with similar visual response properties excite each other, but the anatomical basis of this recurrent synaptic network is unknown. Here we combined physiological imaging and large-scale electron microscopy to study an excitatory network in V1. We found that layer 2/3 neurons organized into subnetworks defined by anatomical connectivity, with more connections within than between groups. More specifically, we found that pyramidal neurons with similar orientation selectivity preferentially formed synapses with each other, despite the fact that axons and dendrites of all orientation selectivities pass near (<5 μm) each other with roughly equal probability. Therefore, we predict that mechanisms of functionally specific connectivity take place at the length scale of spines. Neurons with similar orientation tuning formed larger synapses, potentially enhancing the net effect of synaptic specificity. With the ability to study thousands of connections in a single circuit, functional connectomics is proving a powerful method to uncover the organizational logic of cortical networks.
Electron microscopy (EM) is widely used for studying cellular structure and network connectivity in the brain. We have built a parallel imaging pipeline using transmission electron microscopes that ...scales this technology, implements 24/7 continuous autonomous imaging, and enables the acquisition of petascale datasets. The suitability of this architecture for large-scale imaging was demonstrated by acquiring a volume of more than 1 mm
of mouse neocortex, spanning four different visual areas at synaptic resolution, in less than 6 months. Over 26,500 ultrathin tissue sections from the same block were imaged, yielding a dataset of more than 2 petabytes. The combined burst acquisition rate of the pipeline is 3 Gpixel per sec and the net rate is 600 Mpixel per sec with six microscopes running in parallel. This work demonstrates the feasibility of acquiring EM datasets at the scale of cortical microcircuits in multiple brain regions and species.
Objectives
Despite the high prevalence of mental disorders among youth (age 12 to 17) and emerging adults (age 18 to 24), few receive mental health (MH) services. Using a cross-sectional study ...design, we examined population characteristics associated with MH service use in this age group from 2011 to 2016.
Methods
Data were from six cycles of the Canadian Community Health Survey (2011–2016). Population characteristics associated with service use were analyzed using logistic regression models for each year. Changes in odds ratios over time were used to examine trends.
Results
Presence of a mood or anxiety disorder had the largest magnitude of association on MH service use in every year. Trends suggested an increased association size between self-rated MH status and service use; lower self-rated MH was associated with a 62% increase in odds of service use in 2011 and an 83% increase in 2016. Being female was associated with increased odds of MH service use (range: 59–107%). Compared with white respondents, individuals who were East and Southeast Asian or South Asian had decreased odds of MH service use. While the association size varied for South Asians, there was a trend toward decreasing likelihood of accessing care (55% decreased odds in 2011, 74% in 2016) for East and Southeast Asians.
Conclusion
Trends suggest changes in population characteristics associated with access to MH care (e.g., self-rated MH status) as well as persistent inequity in MH service use in Canada for males and individuals from Asian ethnic groups.
Bedtime resistance and night waking are common sleep problems throughout childhood, especially in the early years. These sleep problems may lead to difficulties in neurobehavioral functioning, but ...most research into childhood sleep problems has not emphasized the importance of the developmental context in which disruptions in neurobehavioral and daytime functioning occur. We review the development of sleep as well as executive functioning (EF) in childhood and suggest that EF may be particularly vulnerable to the effects of these common childhood sleep problems because of its prolonged course of maturation. Behavioral problems associated with common sleep problems suggest poor self-regulation in the context of sleep loss, and developing EF skills play important roles in self-regulation. A research agenda that considers a developmental approach to sleep and sleep problems in the context of childhood EF performance is outlined to promote future research in this area.
Turnbull K; Reid GJ; Morton JB. Behavioral sleep problems and their potential impact on developing executive function in children.
2013;36(7):1077-1084.
Behavioral sleep problems in early childhood are common, affecting about 25% of children, and include symptoms such as problems going to sleep and staying asleep. This review employed the ...developmental psychopathology framework and 4P model (Predisposing, Precipitating, Perpetuating, Protective) to organize the diverse risk/protective factors (distal variables experienced indirectly by the child) and processes (proximal variables experienced directly by the child) for child sleep problems among preschool (1–5 y) and school-age (6–10 y) children. Variables were categorized into biological, psychological, and environmental factors/processes at the individual, family/parent, and community levels. The quality of evidence was assessed using GRADE. A literature search identified 98 articles meeting inclusion criteria. Older child age, difficult temperament, previous sleep problems, externalizing psychopathology, internalizing psychopathology, and electronics use (e.g., bedtime TV viewing) were identified as child risk variables predicting sleep problems. Parental presence at bedtime (risk), negative parenting style (e.g., lax or permissive parenting; risk), consistent bedtime routines (protective), and lower composite socioeconomic status (risk) were identified as family/parent variables predicting child sleep problems. No well-established predictors were found at the community level. Future research should employ advanced research designs more frequently and investigate: 1) risk pathways across development; and 2) nightly fluctuations in sleep problems.
The term level of care is utilized in mental health care to refer to the different ways in which treatment can be delivered, including qualitative (e.g., modality, approach, setting) and quantitative ...(e.g., number of sessions, frequency of sessions) variations in services. The concept is often embedded in models of care and measures, yet there is no agreed upon definition or understanding of what it encompasses. A scoping review of level of care conceptualizations in models of care, and triage and service use measures was conducted. Twenty-nine conceptualizations across 63 articles were identified, 12 focused on qualitative components, four on quantitative components, and 13 on a combination of qualitative and quantitative components. A conceptual model to integrate the literature reviewed is proposed.
Pesticide exposure, infectious disease, and nutritional stress contribute to honey bee mortality and a high rate of colony loss. This realization has fueled a decades-long investigation into the ...single and combined effects of each stressor and their overall bearing on insect physiology. However, one element largely missing from this research effort has been the evaluation of underlying microbial communities in resisting environmental stressors and their influence on host immunity and disease tolerance. In humans, multigenerational bombardment by antibiotics is linked with many contemporary diseases. Here, we draw a parallel conclusion for the case in honey bees and suggest that chronic exposure to antimicrobial xenobiotics can systematically deplete honey bees of their microbes and hamper cross-generational preservation of host-adapted symbionts that are crucial to health.
Honey bees possess a distinct core microbiota that contributes greatly to host stress tolerance and disease resistance.Mounting evidence suggests that loss or depletion of key symbionts can weaken immunity, exacerbate pesticide toxicity, and reduce host nutritional status.Agrochemicals, many of which exhibit hidden antimicrobial properties, pose a major threat and have the potential to irreversibly damage the honey bee microbiota.Genetically engineered symbionts as well as naturally immunostimulatory Lactobacillus strains offer promise of being able to 'reset' dysbiotic microbiota phenotypes via modulation of host defense systems.Consideration of the insect microbiota should become standard practice during agrochemical risk assessments.
Daytime sleep during the preschool years (i.e., 1-5-years-old) is characterized by high inter-child variability in several components of nap behavior, including nap duration, nap timing, and the ...proportion of sleep during daytime. We used an empirical approach to examine variations amongst children in these aspects of napping and investigated correlates of these components of nap behavior.
A large, nationally representative sample (N = 702) of Canadian parents completed an online survey, including a one-month retrospective report of their 1.5–5 year old's daytime and nighttime sleep behavior and other questionnaires. To understand patterns of children's nap behaviors we applied Latent Profile Analysis (LPA) to typical nap duration, typical timing of naps, frequency of naps, proportion of sleep during the daytime, and the proportion of naps which were spontaneous (i.e., child just fell asleep). Then, multinominal logistic regression was used to examine correlates of profile membership.
Four profiles of children emerged: (1) regular nappers; (2) intermittent nappers; (3) spontaneous nappers; and (4) non-nappers. After controlling for demographic variables (e.g., child age, sex, ethnicity) and known correlates of napping behaviors (e.g., birthweight, nighttime sleep duration), profile membership was related to parents' beliefs about napping, parents’ own nap behaviors, family functioning, and child nighttime sleep problems in a multinominal logistic regression.
An empirical approach aided in understanding the inter-child variability in napping amongst preschool-age children. Parental beliefs about napping and the home environment were shown to be critical factors influencing this variability.
Display omitted
•The profiles were regular, intermittent, spontaneous, and non-napping.•Child age was not related to intermittent or spontaneous napping.•Parental beliefs and parents own nap behaviors predicted children's nap behavior.•Stable and predictable family functioning may support flexible approaches to naps.
The current study examined the joint effects of stress, social support, and self-esteem on adjustment to university. First-year undergraduate students (N = 115) were assessed during the first ...semester and again 10 weeks later, during the second semester of the academic year. Multiple regressions predicting adjustment to university from perceived social support (friends and family), self-esteem (academic, social, and global), and stress were conducted. From the fall to winter semesters, increased social support from friends, but not from family, predicted improved adjustment. Decreased stress predicted improved overall, academic, personal-emotional, and social adjustment. Increased global, academic, and social self-esteem predicted decreased depression and increased academic and social adjustment. Results are discussed with respect to potential mechanisms through which support and self-esteem may operate. (Contains 4 tables.)
PDF
