Tutorial: a guide to diffusion MRI and structural connectomics.

Diffusion magnetic resonance imaging (dMRI) is a versatile imaging technique that has gained popularity thanks to its sensitive ability to measure displacement of water molecules within a living tissue on a micrometer scale. Although dMRI has been around since the early 1990s, its applications are constantly evolving, primarily regarding the inference of structural connectomics from nerve fiber trajectories. However, these applications require expertise in image processing and statistics, and it can be difficult for a newcomer to choose an appropriate pipeline to fit their research needs, not least because dMRI is such a flexible methodology that dozens of acquisition and analysis pipelines have been developed over the years.

Weighting the structural connectome: Exploring its impact on network properties and predicting cognitive performance in the human brain.

Brain function does not emerge from isolated activity, but rather from the interactions and exchanges between neural elements that form a network known as the connectome. The human connectome consists of structural and functional aspects. The structural connectome (SC) represents the anatomical connections, and the functional connectome represents the resulting dynamics that emerge from this arrangement of structures.

Relation of connectome topology to brain volume across 103 mammalian species.

The brain connectome is an embedded network of anatomically interconnected brain regions, and the study of its topological organization in mammals has become of paramount importance due to its role in scaffolding brain function and behavior. Unlike many other observable networks, brain connections incur material and energetic cost, and their length and density are volumetrically constrained by the skull. Thus, an open question is how differences in brain volume impact connectome topology.

Clustering the cortical laminae: in vivo parcellation.

The laminar microstructure of the cerebral cortex has distinct anatomical characteristics of the development, function, connectivity, and even various pathologies of the brain. In recent years, multiple neuroimaging studies have utilized magnetic resonance imaging (MRI) relaxometry to visualize and explore this intricate microstructure, successfully delineating the cortical laminar components. Despite this progress, T1 is still primarily considered a direct measure of myeloarchitecture (myelin content), rather than a probe of tissue cytoarchitecture (cellular composition).

Expanding connectomics to the laminar level: A perspective.

Despite great progress in uncovering the complex connectivity patterns of the human brain over the last two decades, the field of connectomics still experiences a bias in its viewpoint of the cerebral cortex. Due to a lack of information regarding exact end points of fiber tracts inside cortical gray matter, the cortex is commonly reduced to a single homogenous unit. Concurrently, substantial developments have been made over the past decade in the use of relaxometry and particularly inversion recovery imaging for exploring the laminar microstructure of cortical gray matter.

Experiencing without knowing? Empirical evidence for phenomenal consciousness without access.

Can one have a phenomenal experience to which one does not have access? That is, can you experience something without knowing? The dissociation between phenomenal (P) and access (A) consciousness is widely debated. A major challenge to the supporters of this dissociation is the apparent inability to experimentally demonstrate that P-without-A consciousness exists; once participants report having a P-experience, they already have access to it. Thus, all previous empirical support for this dissociation is indirect.

Interpreting the ECG in patients with chest pain and right bundle branch block: A case report.

A patient with right bundle branch block (RBBB) presented with chest pain. An ECG showed ST-elevation in leads V1, V2, and aVR, with widespread ST-depression in leads II, aVF, I, aVL, and V4-6. The initial ECG interpretation missed ST-elevation myocardial infarction (STEMI), as ST-elevation thresholds were not reached.

Amyloid transthyretin cardiac amyloidosis with different manifestations, test findings and types.

Amyloid transthyretin amyloidosis usually presents with cardiac amyloidosis manifestations, most commonly with a heart failure syndrome. The history and physical examination offer clues of other cardiac and extracardiac manifestations. Taking a detailed history is essential in elucidating pertinent family and medical history that may increase suspicion for amyloidosis.

A Method for In-Vivo Mapping of Axonal Diameter Distributions in the Human Brain Using Diffusion-Based Axonal Spectrum Imaging (AxSI).

In this paper we demonstrate a generalized and simplified pipeline called axonal spectrum imaging (AxSI) for in-vivo estimation of axonal characteristics in the human brain. Whole-brain estimation of the axon diameter, in-vivo and non-invasively, across all fiber systems will allow exploring uncharted aspects of brain structure and function relations with emphasis on connectivity and connectome analysis. While axon diameter mapping is important in and of itself, its correlation with conduction velocity will allow, for the first time, the explorations of information transfer mechanisms within the brain.

Bats experience age-related hearing loss (presbycusis).

Hearing loss is a hallmark of aging, typically initially affecting the higher frequencies. In echolocating bats, the ability to discern high frequencies is essential. However, nothing is known about age-related hearing loss in bats, and they are often assumed to be immune to it.

Outcomes of Transcatheter Aortic Valve Replacement in Patients With Coexisiting Amyloidosis: Mortality, Stroke, and Readmission.

Background: Cardiac amyloidosis can coexist in patients with severe aortic stenosis. There are limited outcomes data on whether this impacts the risk of transcatheter aortic valve replacement (TAVR).

Objectives: The authors aimed to investigate the effect of amyloidosis on outcomes of TAVR.

Outcomes of Mitral Transcatheter Edge-to-Edge Repair in Patients With Rheumatic Heart Disease.

Mitral transcatheter edge-to-edge repair (TEER) in patients with rheumatic heart disease (RHD) is challenging owing to leaflet thickening and calcification but is performed in select cases. Limited data exist on its outcomes. The aim of this analysis was to investigate the safety and efficacy of mitral TEER in patients with severe symptomatic rheumatic mitral regurgitation.

Connectome topology of mammalian brains and its relationship to taxonomy and phylogeny.

Network models of anatomical connections allow for the extraction of quantitative features describing brain organization, and their comparison across brains from different species. Such comparisons can inform our understanding of between-species differences in brain architecture and can be compared to existing taxonomies and phylogenies. Here we performed a quantitative comparative analysis using the MaMI database (Tel Aviv University), a collection of brain networks reconstructed from diffusion MRI spanning 125 species and 12 taxonomic orders or superorders.

A connectomics-based taxonomy of mammals.

Mammalian taxonomies are conventionally defined by morphological traits and genetics. How species differ in terms of neural circuits and whether inter-species differences in neural circuit organization conform to these taxonomies is unknown. The main obstacle to the comparison of neural architectures has been differences in network reconstruction techniques, yielding species-specific connectomes that are not directly comparable to one another.

Utilization Rate and Outcomes of Intravascular Imaging in Elderly Patients Presenting With ST-Elevation Myocardial Infarction.

Background: Elderly patients presenting with ST-elevation myocardial infarction (STEMI) represent a vulnerable population with comorbid conditions and complex coronary anatomy. We aimed to describe the utilization rate and outcomes of intravascular imaging to guide percutaneous coronary intervention (PCI) in this population.

Methods: The Nationwide Readmissions Database was queried for all hospitalizations for STEMI involving PCI from 2018 to 2019.

Meta-Analysis of Efficacy of Vasopressin During Cardiopulmonary Resuscitation.

Randomized controlled trials evaluating the efficacy of vasopressin versus standard of care during cardiopulmonary resuscitation (CPR) have yielded conflicting results. An electronic search of MEDLINE, Cochrane, and Embase databases was conducted through February 2022 for randomized controlled trials that evaluated the outcomes of vasopressin versus standard of care during CPR among patients with cardiac arrest. The primary outcome was the likelihood of spontaneous circulation (ROSC) return.

Age Differences in Recovery Rate Following an Aerobic-Based Exercise Protocol Inducing Muscle Damage Among Amateur, Male Athletes.

Compare recovery rates between active young (Y) and middle-aged (MA) males up to 48H post aerobically based, exercise-induced muscle damage (EIMD) protocol. A secondary aim was to explore the relationships between changes in indices associated with EIMD and recovery throughout this timeframe. Twenty-eight Y ( = 14, 26.

Modelling the laminar connectome of the human brain.

The human connectome is the complete structural description of the network of connections and elements that form the 'wiring diagram' of the brain. Due to the current scarcity of information regarding laminar end points of white matter tracts inside cortical grey matter, tractography remains focused on cortical partitioning into regions, while ignoring radial partitioning into laminar components. To overcome this biased representation of the cortex as a single homogenous unit, we use a recent data-derived model of cortical laminar connectivity, which has been further explored and corroborated in the macaque brain by comparison to published studies.

Digital health intervention in patients with recent hospitalization for acute heart failure: A systematic review and meta-analysis of randomized trials.

Aim: To examine the efficacy of digital health interventions (DHI) versus standard of care among patients with prior heart failure (HF) hospitalization.

Methods: An electronic search of MEDLINE, Cochrane, OVID, CINHAL and ERIC, databases was performed through August 2021 for randomized clinical trials that evaluated the outcomes with DHI among patients with HF. Data were pooled using the random-effects model.

In vivo measurements of lamination patterns in the human cortex.

The laminar composition of the cerebral cortex is tightly connected to the development and connectivity of the brain, as well as to function and pathology. Although most of the research on the cortical layers is done with the aid of ex vivo histology, there have been recent attempts to use magnetic resonance imaging (MRI) with potential in vivo applications. However, the high-resolution MRI technology and protocols required for such studies are neither common nor practical.

Regenerating the Injured Spinal Cord at the Chronic Phase by Engineered iPSCs-Derived 3D Neuronal Networks.

Cell therapy using induced pluripotent stem cell-derived neurons is considered a promising approach to regenerate the injured spinal cord (SC). However, the scar formed at the chronic phase is not a permissive microenvironment for cell or biomaterial engraftment or for tissue assembly. Engineering of a functional human neuronal network is now reported by mimicking the embryonic development of the SC in a 3D dynamic biomaterial-based microenvironment.

Altered White Matter and microRNA Expression in a Murine Model Related to Williams Syndrome Suggests That miR-34b/c Affects Brain Development via and Modulation.

Williams syndrome (WS) is a multisystem neurodevelopmental disorder caused by a de novo hemizygous deletion of ~26 genes from chromosome 7q11.23, among them the general transcription factor II-I (). By studying a novel murine model for the hypersociability phenotype associated with WS, we previously revealed surprising aberrations in myelination and cell differentiation properties in the cortices of mutant mice compared to controls.