Neuroimaging of Central Nervous System Infections.

Neuroimaging plays a key role in the diagnosis of central nervous system (CNS) infections, as well as common infectious mimics. Standard imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI), as well as advanced techniques such as vessel wall imaging and MR spectroscopy, are becoming widely used in many areas of the world and are valuable tools to aid neurologists in clinical practice. This review seeks to elucidate patterns of infectious pathogen tropism in the brain and spine, detail key imaging features of specific neuroinfectious pathogens such as patterns of enhancement and formation of mass lesions, and improve understanding of the sequential development of CNS infections and their complications including stroke and hydrocephalus.

Education Research: Bedside Rounding Alliance for Internal Medicine & Neurology (BRAINs): A Trainee-Led Program to Promote Residents' Confidence With Neurology.

Introduction And Problem Statement: Patients with neurologic symptoms are often first assessed by general medical providers, many of whom endorse low confidence and knowledge in evaluating neurologic patients. To address this gap, we designed, implemented, and evaluated the Bedside Rounding Alliance for Internal Medicine & Neurology Residents (BRAINs) Program.

Objectives: Program objectives for internal medicine residents (IMRs) were to develop an approach to obtaining a focused neurologic history and to performing a focused physical examination.

Neurologic Outcomes in People With Multiple Sclerosis Treated With Immune Checkpoint Inhibitors for Oncologic Indications.

Background And Objectives: Immune checkpoint inhibitors (ICIs) are increasingly used against various cancers but are associated with immune-related adverse events (irAEs). Risk of irAEs may be higher in patients with certain preexisting autoimmune diseases, and these patients may also experience exacerbation of the underlying autoimmune disease following ICI initiation. People with multiple sclerosis (MS) have mostly been excluded from clinical trials of ICIs, so data on the safety of ICIs in MS are limited.

SATB2 organizes the 3D genome architecture of cognition in cortical neurons.

The DNA-binding protein SATB2 is genetically linked to human intelligence. We studied its influence on the three-dimensional (3D) epigenome by mapping chromatin interactions and accessibility in control versus SATB2-deficient cortical neurons. We find that SATB2 affects the chromatin looping between enhancers and promoters of neuronal-activity-regulated genes, thus influencing their expression.

Schizophrenia-associated somatic copy-number variants from 12,834 cases reveal recurrent and disruptions.

While germline copy-number variants (CNVs) contribute to schizophrenia (SCZ) risk, the contribution of somatic CNVs (sCNVs)-present in some but not all cells-remains unknown. We identified sCNVs using blood-derived genotype arrays from 12,834 SCZ cases and 11,648 controls, filtering sCNVs at loci recurrently mutated in clonal blood disorders. Likely early-developmental sCNVs were more common in cases (0.

Neuron-specific chromosomal megadomain organization is adaptive to recent retrotransposon expansions.

Regulatory mechanisms associated with repeat-rich sequences and chromosomal conformations in mature neurons remain unexplored. Here, we map cell-type specific chromatin domain organization in adult mouse cerebral cortex and report strong enrichment of Endogenous Retrovirus 2 (ERV2) repeat sequences in the neuron-specific heterochromatic B megabase-scaling subcompartment. Single molecule long-read sequencing and comparative Hi-C chromosomal contact mapping in wild-derived SPRET/EiJ (Mus spretus) and laboratory inbred C57BL/6J (Mus musculus) reveal neuronal reconfigurations tracking recent ERV2 expansions in the murine germline, with significantly higher B contact frequencies at sites with ongoing insertions in Mus musculus.

Prenatal Δ-Tetrahydrocannabinol Exposure in Males Leads to Motivational Disturbances Related to Striatal Epigenetic Dysregulation.

Background: Cannabis remains one of the most widely abused drugs during pregnancy. In utero exposure to its principal psychoactive component, Δ-tetrahydrocannabinol (THC), can result in long-term neuropsychiatric risk for the progeny. This study investigated epigenetic signatures underlying these enduring consequences.

A computational tool (H-MAGMA) for improved prediction of brain-disorder risk genes by incorporating brain chromatin interaction profiles.

Most risk variants for brain disorders identified by genome-wide association studies reside in the noncoding genome, which makes deciphering biological mechanisms difficult. A commonly used tool, multimarker analysis of genomic annotation (MAGMA), addresses this issue by aggregating single nucleotide polymorphism associations to nearest genes. Here we developed a platform, Hi-C-coupled MAGMA (H-MAGMA), that advances MAGMA by incorporating chromatin interaction profiles from human brain tissue across two developmental epochs and two brain cell types.

A chromosomal connectome for psychiatric and metabolic risk variants in adult dopaminergic neurons.

Background: Midbrain dopaminergic neurons (MDN) represent 0.0005% of the brain's neuronal population and mediate cognition, food intake, and metabolism. MDN are also posited to underlay the neurobiological dysfunction of schizophrenia (SCZ), a severe neuropsychiatric disorder that is characterized by psychosis as well as multifactorial medical co-morbidities, including metabolic disease, contributing to markedly increased morbidity and mortality.

Use of the epigenetic toolbox to contextualize common variants associated with schizophrenia risk .

Schizophrenia is a debilitating psychiatric disorder with a complex genetic architecture and limited understanding of its neuropathology, reflected by the lack of diagnostic measures and effective pharmacological treatments. Geneticists have recently identified more than 145 risk loci comprising hundreds of common variants of small effect sizes, most of which lie in noncoding genomic regions. This review will discuss how the epigenetic toolbox can be applied to contextualize genetic findings in schizophrenia.

CRISPR-based functional evaluation of schizophrenia risk variants.

As expanding genetic and genomic studies continue to implicate a growing list of variants contributing risk to neuropsychiatric disease, an important next step is to understand the functional impact and points of convergence of these risk factors. Here, with a focus on schizophrenia, we survey the most recent findings of the rare and common variants underlying genetic risk for schizophrenia. We discuss the ongoing efforts to validate these variants in post-mortem brain tissue, as well as new approaches to combine CRISPR-based genome engineering with patient-specific human induced pluripotent stem cell (hiPSC)-based models, in order to identify putative causal schizophrenia loci that regulate gene expression and cellular function.

Spatial genome exploration in the context of cognitive and neurological disease.

The 'non-linear' genome, or the spatial proximity of non-contiguous sequences, emerges as an important regulatory layer for genome organization and function, including transcriptional regulation. Here, we review recent genome-scale chromosome conformation mappings ('Hi-C') in developing and adult human and mouse brain. Neural differentiation is associated with widespread remodeling of the chromosomal contact map, reflecting dynamic changes in cell-type-specific gene expression programs, with a massive (estimated 20-50%) net loss of chromosomal contacts that is specific for the neuronal lineage.

Neuron-specific signatures in the chromosomal connectome associated with schizophrenia risk.

To explore the developmental reorganization of the three-dimensional genome of the brain in the context of neuropsychiatric disease, we monitored chromosomal conformations in differentiating neural progenitor cells. Neuronal and glial differentiation was associated with widespread developmental remodeling of the chromosomal contact map and included interactions anchored in common variant sequences that confer heritable risk for schizophrenia. We describe cell type-specific chromosomal connectomes composed of schizophrenia risk variants and their distal targets, which altogether show enrichment for genes that regulate neuronal connectivity and chromatin remodeling, and evidence for coordinated transcriptional regulation and proteomic interaction of the participating genes.

Chromosomal Conformations and Epigenomic Regulation in Schizophrenia.

Chromosomal conformations, including promoter-enhancer loops, provide a critical regulatory layer for the transcriptional machinery. Therefore, schizophrenia, a common psychiatric disorder associated with broad changes in neuronal gene expression in prefrontal cortex and other brain regions implicated in psychosis, could be associated with alterations in higher-order chromatin. Here, we review early studies on spatial genome organization in the schizophrenia postmortem brain and discuss how integrative approaches using cell culture and animal model systems could gain deeper insight into the potential roles of higher-order chromatin for the neurobiology of and novel treatment avenues for common psychiatric disease.

Evaluating Synthetic Activation and Repression of Neuropsychiatric-Related Genes in hiPSC-Derived NPCs, Neurons, and Astrocytes.

Modulation of transcription, either synthetic activation or repression, via dCas9-fusion proteins is a relatively new methodology with the potential to facilitate high-throughput up- or downregulation studies of gene function. Genetic studies of neurodevelopmental disorders have identified a growing list of risk variants, including both common single-nucleotide variants and rare copy-number variations, many of which are associated with genes having limited functional annotations. By applying a CRISPR-mediated gene-activation/repression platform to populations of human-induced pluripotent stem cell-derived neural progenitor cells, neurons, and astrocytes, we demonstrate that it is possible to manipulate endogenous expression levels of candidate neuropsychiatric risk genes across these three cell types.

The methyltransferase SETDB1 regulates a large neuron-specific topological chromatin domain.

We report locus-specific disintegration of megabase-scale chromosomal conformations in brain after neuronal ablation of Setdb1 (also known as Kmt1e; encodes a histone H3 lysine 9 methyltransferase), including a large topologically associated 1.2-Mb domain conserved in humans and mice that encompasses >70 genes at the clustered protocadherin locus (hereafter referred to as cPcdh). The cPcdh topologically associated domain (TAD) in neurons from mutant mice showed abnormal accumulation of the transcriptional regulator and three-dimensional (3D) genome organizer CTCF at cryptic binding sites, in conjunction with DNA cytosine hypomethylation, histone hyperacetylation and upregulated expression.

Spatial genome organization and cognition.

Nonrandom chromosomal conformations, including promoter-enhancer loopings that bypass kilobases or megabases of linear genome, provide a crucial layer of transcriptional regulation and move vast amounts of non-coding sequence into the physical proximity of genes that are important for neurodevelopment, cognition and behaviour. Activity-regulated changes in the neuronal '3D genome' could govern transcriptional mechanisms associated with learning and plasticity, and loop-bound intergenic and intronic non-coding sequences have been implicated in psychiatric and adult-onset neurodegenerative disease. Recent studies have begun to clarify the roles of spatial genome organization in normal and abnormal cognition.

Interpreter training for medical students: pilot implementation and assessment in a student-run clinic.

Background: Trained medical interpreters are instrumental to patient satisfaction and quality of care. They are especially important in student-run clinics, where many patients have limited English proficiency. Because student-run clinics have ties to their medical schools, they have access to bilingual students who may volunteer to interpret, but are not necessarily formally trained.