Medicine and Health Sciences Commons^™

Limited Nerve Regeneration Across Acellular Nerve Allografts (Anas) Coincides With Changes In Blood Vessel Morphology And The Development Of A Pro-Inflammatory Microenvironment, Jesús A Acevedo Cintrón, Daniel A Hunter, Lauren Schellhardt, Deng Pan, Susan E Mackinnon, Matthew D Wood

2020-Current year OA Pubs

The use of acellular nerve allografts (ANAs) to reconstruct long nerve gaps (>3 cm) is associated with limited axon regeneration. To understand why ANA length might limit regeneration, we focused on identifying differences in the regenerative and vascular microenvironment that develop within ANAs based on their length. A rat sciatic nerve gap model was repaired with either short (2 cm) or long (4 cm) ANAs, and histomorphometry was used to measure myelinated axon regeneration and blood vessel morphology at various timepoints (2-, 4- and 8-weeks). Both groups demonstrated robust axonal regeneration within the proximal graft region, which continued across …

Topographical And Cell Type-Specific Connectivity Of Rostral And Caudal Forelimb Corticospinal Neuron Populations, Lina Marcela Carmona, Eric D Thomas, Kimberly Smith, Bosiljka Tasic, Rui M Costa, Anders Nelson

Journal Articles

Corticospinal neurons (CSNs) synapse directly on spinal neurons, a diverse assortment of cells with unique structural and functional properties necessary for body movements. CSNs modulating forelimb behavior fractionate into caudal forelimb area (CFA) and rostral forelimb area (RFA) motor cortical populations. Despite their prominence, the full diversity of spinal neurons targeted by CFA and RFA CSNs is uncharted. Here, we use anatomical and RNA sequencing methods to show that CSNs synapse onto a remarkably selective group of spinal cell types, favoring inhibitory populations that regulate motoneuron activity and gate sensory feedback. CFA and RFA CSNs target similar spinal neuron types, …

Distributed Feature Representations Of Natural Stimuli Across Parallel Retinal Pathways, Jen-Chun Hsiang, Ning Shen, Florentina Soto, Daniel Kerschensteiner

2020-Current year OA Pubs

How sensory systems extract salient features from natural environments and organize them across neural pathways is unclear. Combining single-cell and population two-photon calcium imaging in mice, we discover that retinal ON bipolar cells (second-order neurons of the visual system) are divided into two blocks of four types. The two blocks distribute temporal and spatial information encoding, respectively. ON bipolar cell axons co-stratify within each block, but separate laminarly between them (upper block: diverse temporal, uniform spatial tuning; lower block: diverse spatial, uniform temporal tuning). ON bipolar cells extract temporal and spatial features similarly from artificial and naturalistic stimuli. In addition, …

Sarm1 Knockout Prevents Type 1 Diabetic Bone Disease In Females Independent Of Neuropathy, Jennifer M. Brazill, Ivana R. Shen, Clarissa S. Craft, Kristann L. Magee, Jay S. Park, Madelyn Lorenz, Amy Strickland, Natalie K. Wee, Xiao Zhang, Alec T. Beeve, Gretchen A. Meyer, Jeffrey Milbrandt, Aaron Diantonio, Erica L. Scheller

2020-Current year OA Pubs

Patients with diabetes have a high risk of developing skeletal diseases accompanied by diabetic peripheral neuropathy (DPN). In this study, we isolated the role of DPN in skeletal disease with global and conditional knockout models of sterile-α and TIR-motif-containing protein-1 (Sarm1). SARM1, an NADase highly expressed in the nervous system, regulates axon degeneration upon a range of insults, including DPN. Global knockout of Sarm1 prevented DPN, but not skeletal disease, in male mice with type 1 diabetes (T1D). Female wild-type mice also developed diabetic bone disease but without DPN. Unexpectedly, global Sarm1 knockout completely protected female mice from T1D-associated bone …

Sirtuin3 Ensures The Metabolic Plasticity Of Neurotransmission During Glucose Deprivation, Anupama Tiwari, Arsalan Hashemiaghdam, Marissa A Laramie, Dario Maschi, Tristaan Haddad, Marion I Stunault, Carmen Bergom, Ali Javaheri, Vitaly Klyachko, Ghazaleh Ashrafi

2020-Current year OA Pubs

Neurotransmission is an energetically expensive process that underlies cognition. During intense electrical activity or dietary restrictions, the glucose level in the brain plummets, forcing neurons to utilize alternative fuels. However, the molecular mechanisms of neuronal metabolic plasticity remain poorly understood. Here, we demonstrate that glucose-deprived neurons activate the CREB and PGC1α transcriptional program, which induces expression of the mitochondrial deacetylase Sirtuin 3 (Sirt3) both in vitro and in vivo. We show that Sirt3 localizes to axonal mitochondria and stimulates mitochondrial oxidative capacity in hippocampal nerve terminals. Sirt3 plays an essential role in sustaining synaptic transmission in the absence of glucose …

The Response Of Dual-Leucine Zipper Kinase (Dlk) To Nocodazole: Evidence For A Homeostatic Cytoskeletal Repair Mechanism, Laura Devault, Chase Mateusiak, John Palucki, Michael Brent, Jeffrey Milbrandt, Aaron Diantonio

2020-Current year OA Pubs

Genetic and pharmacological perturbation of the cytoskeleton enhances the regenerative potential of neurons. This response requires Dual-leucine Zipper Kinase (DLK), a neuronal stress sensor that is a central regulator of axon regeneration and degeneration. The damage and repair aspects of this response are reminiscent of other cellular homeostatic systems, suggesting that a cytoskeletal homeostatic response exists. In this study, we propose a framework for understanding DLK mediated neuronal cytoskeletal homeostasis. We demonstrate that low dose nocodazole treatment activates DLK signaling. Activation of DLK signaling results in a DLK-dependent transcriptional signature, which we identify through RNA-seq. This signature includes genes likely …

Diversity In Homeostatic Calcium Set Points Predicts Retinal Ganglion Cell Survival Following Optic Nerve Injury In Vivo, Sean Mccracken, Michael J Fitzpatrick, Allison L Hall, Zelun Wang, Daniel Kerschensteiner, Josh L Morgan, Philip R Williams

2020-Current year OA Pubs

Retinal ganglion cell (RGC) degeneration drives vision loss in blinding conditions. RGC death is often triggered by axon degeneration in the optic nerve. Here, we study the contributions of dynamic and homeostatic Ca

Self-Renewing Macrophages In Dorsal Root Ganglia Contribute To Promote Nerve Regeneration, Rui Feng, Vishnu Muraleedharan Saraswathy, Mayssa H Mokalled, Valeria Cavalli

2020-Current year OA Pubs

Sensory neurons located in dorsal root ganglia (DRG) convey sensory information from peripheral tissue to the brain. After peripheral nerve injury, sensory neurons switch to a regenerative state to enable axon regeneration and functional recovery. This process is not cell autonomous and requires glial and immune cells. Macrophages in the DRG (DRGMacs) accumulate in response to nerve injury, but their origin and function remain unclear. Here, we mapped the fate and response of DRGMacs to nerve injury using macrophage depletion, fate-mapping, and single-cell transcriptomics. We identified three subtypes of DRGMacs after nerve injury in addition to a small population of …

Macrophage Depletion Blocks Congenital Sarm1-Dependent Neuropathy, Caitlin B Dingwall, Amy Strickland, Sabrina W Yum, Aldrin Ky Yim, Jian Zhu, Peter L. Wang, Yurie Yamada, Robert E. Schmidt, Yo Sasaki, A. Joseph Bloom, Aaron Diantonio, Jeffrey Milbrandt

2020-Current year OA Pubs

Axon loss contributes to many common neurodegenerative disorders. In healthy axons, the axon survival factor NMNAT2 inhibits SARM1, the central executioner of programmed axon degeneration. We identified 2 rare NMNAT2 missense variants in 2 brothers afflicted with a progressive neuropathy syndrome. The polymorphisms resulted in amino acid substitutions V98M and R232Q, which reduced NMNAT2 NAD+-synthetase activity. We generated a mouse model to mirror the human syndrome and found that Nmnat2V98M/R232Q compound-heterozygous CRISPR mice survived to adulthood but developed progressive motor dysfunction, peripheral axon loss, and macrophage infiltration. These disease phenotypes were all SARM1-dependent. Remarkably, macrophage depletion therapy blocked and reversed …

A New Mouse Model Of Charcot-Marie-Tooth 2j Neuropathy Replicates Human Axonopathy And Suggest Alteration In Axo-Glia Communication, Ghjuvan'ghjacumu Shackleford, Yo Sasaki, Et Al.

2020-Current year OA Pubs

Myelin is essential for rapid nerve impulse propagation and axon protection. Accordingly, defects in myelination or myelin maintenance lead to secondary axonal damage and subsequent degeneration. Studies utilizing genetic (CNPase-, MAG-, and PLP-null mice) and naturally occurring neuropathy models suggest that myelinating glia also support axons independently from myelin. Myelin protein zero (MPZ or P0), which is expressed only by Schwann cells, is critical for myelin formation and maintenance in the peripheral nervous system. Many mutations in MPZ are associated with demyelinating neuropathies (Charcot-Marie-Tooth disease type 1B [CMT1B]). Surprisingly, the substitution of threonine by methionine at position 124 of P0 …

Imaging Peripheral Nerve Micro-Anatomy With Muse, 2d And 3d Approaches, Chaitanya Kolluru, Austin Todd, Aniruddha R Upadhye, Yehe Liu, Mikhail Y Berezin, Farzad Fereidouni, Richard M Levenson, Yanming Wang, Andrew J Shoffstall, Michael W Jenkins, David L Wilson

2020-Current year OA Pubs

Understanding peripheral nerve micro-anatomy can assist in the development of safe and effective neuromodulation devices. However, current approaches for imaging nerve morphology at the fiber level are either cumbersome, require substantial instrumentation, have a limited volume of view, or are limited in resolution/contrast. We present alternative methods based on MUSE (Microscopy with Ultraviolet Surface Excitation) imaging to investigate peripheral nerve morphology, both in 2D and 3D. For 2D imaging, fixed samples are imaged on a conventional MUSE system either label free (via auto-fluorescence) or after staining with fluorescent dyes. This method provides a simple and rapid technique to visualize myelinated …

Distinct Developmental And Degenerative Functions Of Sarm1 Require Nad+ Hydrolase Activity, E. J. Brace, Kow Essuman, Xianrong Mao, John Palucki, Yo Sasaki, Jeff Milbrandt, Aaron Diantonio

2020-Current year OA Pubs

SARM1 is the founding member of the TIR-domain family of NAD+ hydrolases and the central executioner of pathological axon degeneration. SARM1-dependent degeneration requires NAD+ hydrolysis. Prior to the discovery that SARM1 is an enzyme, SARM1 was studied as a TIR-domain adaptor protein with non-degenerative signaling roles in innate immunity and invertebrate neurodevelopment, including at the Drosophila neuromuscular junction (NMJ). Here we explore whether the NADase activity of SARM1 also contributes to developmental signaling. We developed transgenic Drosophila lines that express SARM1 variants with normal, deficient, and enhanced NADase activity and tested their function in NMJ development. We find that NMJ …

Selective Axonal Transport Through Branch Junctions Is Directed By Growth Cone Signaling And Mediated By Kif1/Kinesin-3 Motors., Stephen R. Tymanskyj, Bridget M. Curran, Le Ma

Department of Neuroscience Faculty Papers

Development and function of nerve cells rely on the orchestration of microtubule-based transport from the cell body into distal axonal terminals. Neurons often have highly elaborate branches innervating multiple targets, but how protein or membrane cargos navigate through branch junctions to specific branch targets is unknown. Here, we demonstrate that anterograde transport of membrane vesicles through axonal branch junctions is highly selective, which is influenced by branch length and more strongly by growth cone motility. Using an optogenetic tool, we demonstrate that signaling from the growth cone can rapidly direct transport through branch junctions. We further demonstrate that such transport …

Centrosome-Dependent Microtubule Modifications Set The Conditions For Axon Formation, Durga Praveen Meka, Ewelina Betleja, Tao Cheng, Moe R Mahjoub, Et Al.

2020-Current year OA Pubs

Microtubule (MT) modifications are critical during axon development, with stable MTs populating the axon. How these modifications are spatially coordinated is unclear. Here, via high-resolution microscopy, we show that early developing neurons have fewer somatic acetylated MTs restricted near the centrosome. At later stages, however, acetylated MTs spread out in soma and concentrate in growing axon. Live imaging in early plated neurons of the MT plus-end protein, EB3, show increased displacement and growth rate near the MTOC, suggesting local differences that might support axon selection. Moreover, F-actin disruption in early developing neurons, which show fewer somatic acetylated MTs, does not …

Transcriptional Control Of Retinal Ganglion Cell Death After Axonal Injury., Stephanie B Syc-Mazurek, Hongtian Stanley Yang, Olivia J Marola, Gareth R Howell, Richard T Libby

Faculty Research 2022

Injury to the axons of retinal ganglion cells (RGCs) is a key pathological event in glaucomatous neurodegeneration. The transcription factors JUN (the target of the c-Jun N-terminal kinases, JNKs) and DDIT3/CHOP (a mediator of the endoplasmic reticulum stress response) have been shown to control the majority of proapoptotic signaling after mechanical axonal injury in RGCs and in other models of neurodegeneration. The downstream transcriptional networks controlled by JUN and DDIT3, which are critical for RGC death, however, are not well defined. To determine these networks, RNA was isolated from the retinas of wild-type mice and mice deficient in Jun, Ddit3, …

Constitutively Active Sarm1 Variants That Induce Neuropathy Are Enriched In Als Patients, A Joseph Bloom, Xianrong Mao, Amy Strickland, Yo Sasaki, Jeffrey Milbrandt, Aaron Diantonio

2020-Current year OA Pubs

BACKGROUND: In response to injury, neurons activate a program of organized axon self-destruction initiated by the NAD

METHODS: To investigate whether naturally occurring human variants might disrupt SARM1 autoinhibition and potentially contribute to risk for neurodegenerative disease, we assayed the enzymatic activity of all 42 rare SARM1 alleles identified among 8507 amyotrophic lateral sclerosis (ALS) patients and 9671 controls. We then intrathecally injected mice with virus expressing SARM1 constructs to test the capacity of an ALS-associated constitutively active SARM1 variant to promote neurodegeneration in vivo.

RESULTS: Twelve out of 42 SARM1 missense variants or small in-frame deletions assayed exhibit constitutive …

Oral Administration Of A Dual Eta/Etb Receptor Antagonist Promotes Neuroprotection In A Rodent Model Of Glaucoma, Bindu Kodati, Nolan R Mcgrady, Hayden B Jefferies, Dorota L Stankowska, Raghu R Krishnamoorthy

Journal Articles

PURPOSE: Glaucoma is a neurodegenerative disease associated with elevated intraocular pressure and characterized by optic nerve axonal degeneration, cupping of the optic disc, and loss of retinal ganglion cells (RGCs). The endothelin (ET) system of vasoactive peptides (ET-1, ET-2, ET-3) and their G-protein coupled receptors (ET

METHODS: Male and female Brown Norway rats were subjected to the Morrison model of ocular hypertension by injection of hypertonic saline through the episcleral veins. Following IOP elevation, macitentan (5 mg/kg body wt) was administered orally 3 days per week, and rats with IOP elevation were maintained for 4 weeks. RGC function was determined …

Neuron-Specific Imp2 Overexpression By Synapsin Promoter-Driven Aav9: A Tool To Study Its Role In Axon Regeneration., Sarah Blizard, Danielle Park, Natalie O'Toole, Sheeva Norooz, Martin Dela Torre, Young Son, Adam Holstein, Scarlett Austin, Joshua Harman, Samantha Haraszti, Daved Fared, Mei Xu

PCOM Scholarly Papers

Insulin-like growth factor II mRNA-binding protein (IMP) 2 is one of the three homologues (IMP1-3) that belong to a conserved family of mRNA-binding proteins. Its alternative splice product is aberrantly expressed in human hepatocellular carcinoma, and it is therefore identified as HCC. Previous works have indicated that IMP1/ZBP1 (zipcode binding protein) is critical in axon guidance and regeneration by regulating localization and translation of specific mRNAs. However, the role of IMP2 in the nervous system is largely unknown. We used the synapsin promoter-driven adeno-associated viral (AAV) 9 constructs for transgene expression both in vitro and in vivo. These viral vectors …

A Neuroskeletal Atlas: Spatial Mapping And Contextualization Of Axon Subtypes Innervating The Long Bones Of C3h And B6 Mice, Madelyn R Lorenz, Jennifer M Brazill, Alec T Beeve, Ivana Shen, Erica L Scheller

2020-Current year OA Pubs

Nerves in bone play well-established roles in pain and vasoregulation and have been associated with progression of skeletal disorders, including osteoporosis, fracture, arthritis, and tumor metastasis. However, isolation of the region-specific mechanisms underlying these relationships is limited by our lack of quantitative methods for neuroskeletal analysis and precise maps of skeletal innervation. To overcome these limitations, we developed an optimized workflow for imaging and quantitative analysis of axons in and around the bone, including validation of Baf53b-Cre in concert with R26R-tdTomato (Ai9) as a robust pan-neuronal reporter system for use in musculoskeletal tissues. In addition, we created comprehensive maps of …

Understanding The Axonal Response To Injury By In Vivo Imaging In The Mouse Spinal Cord: A Tale Of Two Branches., Binhai Zheng, Ariana O Lorenzana, Le Ma

Department of Neuroscience Faculty Papers

Understanding the basic properties of how axons respond to injury in the mammalian central nervous system (CNS) is of fundamental value for developing strategies to promote neural repair. Axons possess complex morphologies with stereotypical branching patterns. However, current knowledge of the axonal response to injury gives little consideration to axonal branches, nor do strategies to promote axon regeneration. This article reviews evidence from in vivo spinal cord imaging that axonal branches markedly impact the degenerative and regenerative responses to injury. At a major bifurcation point, depending on whether one or both axonal branches are injured, neurons may choose either a …

Fate Of Neural Progenitor Cells Transplanted Into Jaundiced And Nonjaundiced Rat Brains., Fu-Chen Yang, Sean M. Riordan, Michelle Winter, Li Gan, Peter G. Smith, Jay L. Vivian, Steven Shapiro, John A. Stanford

Manuscripts, Articles, Book Chapters and Other Papers

High levels of bilirubin in infants can cause kernicterus, which includes basal ganglia damage and dystonia. Stem cell transplantation may be an effective treatment for this disease. In this study, we transplanted human neural progenitor cells differentiated toward propriospinal interneurons into the striatum of 20-day-old spontaneously jaundiced (jj) Gunn rats and nonjaundiced (Nj) littermates. Using immunohistochemical methods, we found that grafted cells survived and grew fibers in jj and Nj brains 3 weeks after transplantation. Grafted cells had a higher survival rate in jj than in Nj brains, suggesting that slightly elevated bilirubin may protect graft survival due to its …

Map7 Regulates Axon Collateral Branch Development In Dorsal Root Ganglion Neurons., Stephen R Tymanskyj, Benjamin Yang, Aditi Falnikar, Angelo C Lepore, Le Ma

Department of Neuroscience Faculty Papers

Collateral branches from axons are key components of functional neural circuits that allow neurons to connect with multiple synaptic targets. Like axon growth and guidance, formation of collateral branches depends on the regulation of microtubules, but how such regulation is coordinated to ensure proper circuit development is not known. Based on microarray analysis, we have identified a role for microtubule-associated protein 7 (MAP7) during collateral branch development of dorsal root ganglion (DRG) sensory neurons. We show that MAP7 is expressed at the onset of collateral branch formation. Perturbation of its expression by overexpression or shRNA knockdown alters axon branching in …

Change In Processing Speed And Its Associations With Cerebral White Matter Microstructure, Muzamil Arshad

Wayne State University Dissertations

The decline of cognition with age is one of the most feared aspects of aging, while the slowing of responses, or reduced processing speed, is one of the most reliable aspects of aging. Slowing of processing has been hypothesized to affect other domains of cognition as well. Despite the well-known slowing-age relationship and central position processing speed plays in theories of cognitive aging the neurobiological mechanisms which underpin slowing is unclear. If we could identify the biology associated with processing speed we could then attempt to develop interventions to mitigate the effects of age on those variables. In turn we …

Imaging Submillisecond Membrane Potential Changes From Individual Regions Of Single Axons, Dendrites And Spines, Srdjan D. Antic

UCHC Articles - Research

A central question in neuronal network analysis is how the interaction between individual neurons produces behavior and behavioral modifications. This task depends critically on how exactly signals are integrated by individual nerve cells functioning as complex operational units. Regional electrical properties of branching neuronal processes which determine the input-output function of any neuron are extraordinarily complex, dynamic, and, in the general case, impossible to predict in the absence of detailed measurements. To obtain such a measurement one would, ideally, like to be able to monitor, at multiple sites, subthreshold events as they travel from the sites of origin (synaptic contacts …

Short Duration Waveforms Recorded Extracellularly From Freely Moving Rats Are Representative Of Axonal Activity, Ashlee A. Robbins, Steven E. Fox, Gregory L. Holmes, Rod C. Scott, Jeremy M. Barry

Dartmouth Scholarship

While extracellular somatic action potentials from freely moving rats have been well characterized, axonal activity has not. We report direct extracellular tetrode recordings of putative axons whose principal feature is a short duration waveform (SDW) with an average peak-trough length less than 179 μs. While SDW recordings using tetrodes have previously been treated as questionable or classified as cells, we hypothesize that they are representative of axonal activity. These waveforms have significantly shorter duration than somatic action potentials, are triphasic and are therefore similar to classic descriptions of microelectrode recordings in white matter and of in vitro action potential propagation …

Degeneration Of Phrenic Motor Neurons Induces Long-Term Diaphragm Deficits Following Mid-Cervical Spinal Contusion In Mice., Charles Nicaise, Rajarshi Putatunda, Tamara J Hala, Kathleen A Regan, David M Frank, Jean-Pierre Brion, Karelle Leroy, Roland Pochet, Megan C Wright, Angelo C Lepore

Department of Neuroscience Faculty Papers

A primary cause of morbidity and mortality following cervical spinal cord injury (SCI) is respiratory compromise, regardless of the level of trauma. In particular, SCI at mid-cervical regions targets degeneration of both descending bulbospinal respiratory axons and cell bodies of phrenic motor neurons, resulting in deficits in the function of the diaphragm, the primary muscle of inspiration. Contusion-type trauma to the cervical spinal cord is one of the most common forms of human SCI; however, few studies have evaluated mid-cervical contusion in animal models or characterized consequent histopathological and functional effects of degeneration of phrenic motor neuron-diaphragm circuitry. We have …

Utilization Of Structural And Biochemical Cues To Enhance Peripheral Nerve Regeneration, Balendu Shekhar Jha

Theses and Dissertations

This study examines the prospects of using the electrospinning process to fabricate tissue engineering scaffolds targeting a variety of regenerative applications, with a primary focus on the production of nerve guides for the treatment of long-defect nerve injuries in the peripheral nervous system. A basic overview of the conventional electrospinning process is provided, and the utility of this fabrication scheme in the production of collagen-based tissue engineering scaffolds is demonstrated. Next, a novel modification of the basic electrospinning process is presented. This process, called two pole air gap electrospinning, was developed to produce nerve guides that exhibit an anisotropic structure …

Mitochondrial Mislocalization Underlies Abeta42-Induced Neuronal Dysfunction In A Drosophila Model Of Alzheimer's Disease., Kanae Iijima-Ando, Stephen A Hearn, Christopher Shenton, Anthony Gatt, Lijuan Zhao, Koichi Iijima

Department of Biochemistry and Molecular Biology Faculty Papers

The amyloid-beta 42 (Abeta42) is thought to play a central role in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial …

Mechanisms Of Primary Axonal Damage In A Viral Model Of Multiple Sclerosis., Jayasri Das Sarma, Lawrence C. Kenyon, Susan T. Hingley, Kenneth S. Shindler

Department of Neurology Faculty Papers

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS. Recent studies have demonstrated that significant axonal injury also occurs in MS patients and correlates with neurological dysfunction, but it is not known whether this neuronal damage is a primary disease process, or occurs only secondary to demyelination. In the current studies, neurotropic strains of mouse hepatitis virus (MHV) that induce meningitis, encephalitis, and demyelination in the CNS, an animal model of MS, were used to evaluate mechanisms of axonal injury. The pathogenic properties of genetically engineered isogenic spike protein recombinant demyelinating and nondemyelinating strains of MHV were compared. …

Mitochondrial Mislocalization Underlies Abeta42-Induced Neuronal Dysfunction In A Drosophila Model Of Alzheimer's Disease., Kanae Iijima-Ando, Stephen A Hearn, Christopher Shenton, Anthony Gatt, Lijuan Zhao, Koichi Iijima

Department of Biochemistry and Molecular Biology Faculty Papers

The amyloid-beta 42 (Abeta42) is thought to play a central role in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial …