Corrigendum: A Pipeline for Volume Electron Microscopy of the Caenorhabditis elegans Nervous System.

[This corrects the article DOI: 10.3389/fncir.2018.00094.]

A Pipeline for Volume Electron Microscopy of the Caenorhabditis elegans Nervous System.

The "connectome," a comprehensive wiring diagram of synaptic connectivity, is achieved through volume electron microscopy (vEM) analysis of an entire nervous system and all associated non-neuronal tissues. White et al. (1986) pioneered the fully manual reconstruction of a connectome using Caenorhabditis elegans. Recent advances in vEM allow mapping new C. elegans connectomes with increased throughput, and reduced subjectivity. Current vEM studies aim to not only fill the remaining gaps in the original connectome, but also address fundamental questions including how the connectome changes during development, the nature of individuality, sexual dimorphism, and how genetic and environmental factors regulate connectivity. Here we describe our current vEM pipeline and projected improvements for the study of the C. elegans nervous system and beyond

Conceptualizing Spirituality and Religion as Psychological Processes: Validation of the Factor Structure of the BMMRS

This study validated previous principal component analyses of the Brief Multidimensional Measure of Religiousness/Spirituality (BMMRS) that have been conducted with persons with diverse medical conditions and traumatic brain injuries from diverse cultures (India, US), ethnicities (African American, Caucasian, South Asian), and religions (Christian, Hindu, Muslim). Participants included 398 healthy undergraduate students who completed the BMMRS online. A principal components factor analysis identified a five factor solution accounting for 64.00% of the variance in scores, labelled as: (1) Positive Spiritual Experience; (2) Negative Spiritual Experience/Congregational Support; (3) Forgiveness; (4) Religious Practices; and (5) Positive Congregational Support. The current analysis is supportive of a conceptual framework in which the BMMRS spiritual and religious variables are best conceptualised in terms of positive/negative psychological processes including: (a) emotional connection with the divine (i.e., spirituality); (b) behavioural rituals/beliefs (i.e., religiosity); and (c) social support (i.e., congregationally based). Implications for psychoneuroimmunological research are discussed

A Pipeline for Volume Electron Microscopy of the Caenorhabditis elegans Nervous System

The “connectome,” a comprehensive wiring diagram of synaptic connectivity, is achieved through volume electron microscopy (vEM) analysis of an entire nervous system and all associated non-neuronal tissues. White et al. (1986) pioneered the fully manual reconstruction of a connectome using Caenorhabditis elegans. Recent advances in vEM allow mapping new C. elegans connectomes with increased throughput, and reduced subjectivity. Current vEM studies aim to not only fill the remaining gaps in the original connectome, but also address fundamental questions including how the connectome changes during development, the nature of individuality, sexual dimorphism, and how genetic and environmental factors regulate connectivity. Here we describe our current vEM pipeline and projected improvements for the study of the C. elegans nervous system and beyond

Global Analyses of Synaptic Remodeling and Wiring Variability of the Developing C. elegans Brain

From birth to adulthood, an animal's nervous system changes to facilitate the maturation, refinement, and expansion of its behavioural repertoire. Studies at individual synapse level have resulted in an assortment of genetic and cellular factors that affect synapse remodeling. What needs to be addressed, however, is whether and how synaptic changes collectively affect the circuit-level maturation and reshaping. My Ph.D. work addresses this question in the C. elegans nervous system. Using serial section-electron microscopy, I mapped the wiring diagram of its brain, or connectome, from birth to adulthood, to examine how and why brain wiring changes with age. I present the wiring diagrams and topology structures reconstructed from eight isogenic wild-type C. elegans, from the first larva to adult stages. By comparing these datasets, I reveal that despite a small and invariant neuron number and isogeneity, a nematode's brain has a large capacity for structural plasticity. Remarkably, the most stable connectivity of the central nervous system is its centralized decision-making circuitry, whereas sensory and motor pathways undergo substantial remodeling. I also find that the synapse remodeling events collectively lead to refined modularity of sensory and motor circuits. The overall topology of the nervous system is largely preserved from birth to adult, establishing a scaffold upon which all developmental and variable synaptic connectivity is built. I analyze the relationship between topology changes, synapse remodeling events, and wiring maturation during development. Four rules correlate synapse remodeling events with the structural characteristics of the L1 brain. Using in silico simulation, I demonstrate that they are sufficient to evolve the adult connectome from that of the L1 larva. These studies demonstrate that brain-wide wiring plasticity is an inherent property of individuals of an isogenic population. The connectome is not a fixed entity, as often assumed, but can itself be a target of developmental programs and external cues. It is necessary to obtain individual-level wiring to interpret plasticity and behaviours. This study has laid the essential foundation to explore how genetic factors, environments, and experiences shape the developing brain.Ph.D

Temperature regulates synaptic subcellular specificity mediated by inhibitory glutamate signaling.

Environmental factors such as temperature affect neuronal activity and development. However, it remains unknown whether and how they affect synaptic subcellular specificity. Here, using the nematode Caenorhabditis elegans AIY interneurons as a model, we found that high cultivation temperature robustly induces defects in synaptic subcellular specificity through glutamatergic neurotransmission. Furthermore, we determined that the functional glutamate is mainly released by the ASH sensory neurons and sensed by two conserved inhibitory glutamate-gated chloride channels GLC-3 and GLC-4 in AIY. Our work not only presents a novel neurotransmission-dependent mechanism underlying the synaptic subcellular specificity, but also provides a potential mechanistic insight into high-temperature-induced neurological defects

Structural Analysis of the Caenorhabditis elegans Dauer Larval Anterior Sensilla by Focused Ion Beam-Scanning Electron Microscopy

At the end of the first larval stage, the nematode Caenorhabditis elegans developing in harsh environmental conditions is able to choose an alternative developmental path called the dauer diapause. Dauer larvae exhibit different physiology and behaviors from non-dauer larvae. Using focused ion beam-scanning electron microscopy (FIB-SEM), we volumetrically reconstructed the anterior sensory apparatus of C. elegans dauer larvae with unprecedented precision. We provide a detailed description of some neurons, focusing on structural details that were unknown or unresolved by previously published studies. They include the following: (1) dauer-specific branches of the IL2 sensory neurons project into the periphery of anterior sensilla and motor or putative sensory neurons at the sub-lateral cords; (2) ciliated endings of URX sensory neurons are supported by both ILso and AMso socket cells near the amphid openings; (3) variability in amphid sensory dendrites among dauers; and (4) somatic RIP interneurons maintain their projection into the pharyngeal nervous system. Our results support the notion that dauer larvae structurally expand their sensory system to facilitate searching for more favorable environments

Filling the gap: adding super-resolution to array tomography for correlated ultrastructural and molecular identification of electrical synapses at the C. elegans connectome

Correlating molecular labeling at the ultrastructural level with high confidence remains challenging. Array tomography (AT) allows for a combination of fluorescence and electron microscopy (EM) to visualize subcellular protein localization on serial EM sections. Here, we describe an application for AT that combines near-native tissue preservation via high-pressure freezing and freeze substitution with super-resolution light microscopy and high-resolution scanning electron microscopy (SEM) analysis on the same section. We established protocols that combine SEM with structured illumination microscopy (SIM) and direct stochastic optical reconstruction microscopy (dSTORM). We devised a method for easy, precise, and unbiased correlation of EM images and super-resolution imaging data using endogenous cellular landmarks and freely available image processing software. We demonstrate that these methods allow us to identify and label gap junctions in Caenorhabditis elegans with precision and confidence, and imaging of even smaller structures is feasible. With the emergence of connectomics, these methods will allow us to fill in the gap-acquiring the correlated ultrastructural and molecular identity of electrical synapses

Corrigendum: A Pipeline for Volume Electron Microscopy of the Caenorhabditis elegans Nervous System.

[This corrects the article DOI: 10.3389/fncir.2018.00094.]