Medicine and Health Sciences Commons^™

The Community Structure Of Functional Brain Networks Exhibits Scale-Specific Patterns Of Inter- And Intra-Subject Variability, Richard F Betzel, Maxwell A Bertolero, Evan M Gordon, Caterina Gratton, Nico U F Dosenbach, Danielle S Bassett

2010-2019 OA Pubs

The network organization of the human brain varies across individuals, changes with development and aging, and differs in disease. Discovering the major dimensions along which this variability is displayed remains a central goal of both neuroscience and clinical medicine. Such efforts can be usefully framed within the context of the brain's modular network organization, which can be assessed quantitatively using computational techniques and extended for the purposes of multi-scale analysis, dimensionality reduction, and biomarker generation. Although the concept of modularity and its utility in describing brain network organization is clear, principled methods for comparing multi-scale communities across individuals and time …

Multispectral Tracing In Densely Labeled Mouse Brain With Ntracer, Douglas H Roossien, John M Webb, Cristina Mazuski, Erik D Herzog, Et Al.

2010-2019 OA Pubs

SUMMARY: This note describes nTracer, an ImageJ plug-in for user-guided, semi-automated tracing of multispectral fluorescent tissue samples. This approach allows for rapid and accurate reconstruction of whole cell morphology of large neuronal populations in densely labeled brains.

AVAILABILITY AND IMPLEMENTATION: nTracer was written as a plug-in for the open source image processing software ImageJ. The software, instructional documentation, tutorial videos, sample image and sample tracing results are available at https://www.cai-lab.org/ntracer-tutorial.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

White Matter Diffusion Alterations Precede Symptom Onset In Autosomal Dominant Alzheimer's Disease, Miguel Ángel Araque Caballero, Tammie Benzinger, Anne M Fagan, Randall J Bateman, Celeste Karch, John C Morris, Jason Hassenstab, Et Al.

2010-2019 OA Pubs

White matter alterations are present in the majority of patients with Alzheimer's disease type dementia. However, the spatiotemporal pattern of white matter changes preceding dementia symptoms in Alzheimer's disease remains unclear, largely due to the inherent diagnostic uncertainty in the preclinical phase and increased risk of confounding age-related vascular disease and stroke in late-onset Alzheimer's disease. In early-onset autosomal-dominantly inherited Alzheimer's disease, participants are destined to develop dementia, which provides the opportunity to assess brain changes years before the onset of symptoms, and in the absence of ageing-related vascular disease. Here, we assessed mean diffusivity alterations in the white matter …

Behavioral And Transcriptomic Analysis Of Trem2-Null Mice: Not All Knockout Mice Are Created Equal, Silvia S Kang, Aishe Kurti, Kelsey E Baker, Chia-Chen Liu, Marco Colonna, Jason D Ulrich, David M Holtzman, Guojun Bu, John D Fryer

2010-2019 OA Pubs

It is clear that innate immune system status is altered in numerous neurodegenerative diseases. Human genetic studies have demonstrated that triggering receptor expressed in myeloid cells 2 (TREM2) coding variants have a strong association with Alzheimer's disease (AD) and other neurodegenerative diseases. To more thoroughly understand the impact of TREM2 in vivo, we studied the behavioral and cognitive functions of wild-type (WT) and Trem2-/- (KO) mice during basal conditions and brain function in the context of innate immune stimulation with peripherally administered lipopolysaccharide (LPS). Early markers of neuroinflammation preceded Aif1 and Trem2 upregulation that occurred at later stages (24-48 h …

Effective Connectivity Measured Using Optogenetically Evoked Hemodynamic Signals Exhibits Topography Distinct From Resting State Functional Connectivity In The Mouse, Adam Q Bauer, Andrew W Kraft, Grant A Baxter, Patrick W Wright, Matthew D Reisman, Annie R Bice, Jasmine J Park, Michael R Bruchas, Abraham Z Snyder, Jin-Moo Lee, Joseph P Culver

2010-2019 OA Pubs

Brain connectomics has expanded from histological assessment of axonal projection connectivity (APC) to encompass resting state functional connectivity (RS-FC). RS-FC analyses are efficient for whole-brain mapping, but attempts to explain aspects of RS-FC (e.g., interhemispheric RS-FC) based on APC have been only partially successful. Neuroimaging with hemoglobin alone lacks specificity for determining how activity in a population of cells contributes to RS-FC. Wide-field mapping of optogenetically defined connectivity could provide insights into the brain's structure-function relationship. We combined optogenetics with optical intrinsic signal imaging to create an efficient, optogenetic effective connectivity (Opto-EC) mapping assay. We examined EC patterns of excitatory …