Neurology Commons^™

High Resolution Time-Course Mapping Of Early Transcriptomic, Molecular And Cellular Phenotypes In Huntington's Disease Cag Knock-In Mice Across Multiple Genetic Backgrounds., Seth A Ament, Jocelynn R Pearl, Andrea Grindeland, Jason St Claire, John C Earls, Marina Kovalenko, Tammy Gillis, Jayalakshmi Mysore, James F Gusella, Jong-Min Lee, Seung Kwak, David Howland, Min Young Lee, David Baxter, Kelsey Scherler, Kai Wang, Donald Geman, Jeffrey B Carroll, Marcy E Macdonald, George Carlson, Vanessa C Wheeler, Nathan D Price, Leroy Hood

Articles, Abstracts, and Reports

Huntington's disease is a dominantly inherited neurodegenerative disease caused by the expansion of a CAG repeat in the HTT gene. In addition to the length of the CAG expansion, factors such as genetic background have been shown to contribute to the age at onset of neurological symptoms. A central challenge in understanding the disease progression that leads from the HD mutation to massive cell death in the striatum is the ability to characterize the subtle and early functional consequences of the CAG expansion longitudinally. We used dense time course sampling between 4 and 20 postnatal weeks to characterize early transcriptomic, …

Repeated Closed Head Injury In Mice Results In Sustained Motor And Memory Deficits And Chronic Cellular Changes, Amanda Nicholle Bolton Hall, Binoy Joseph, Jennifer M. Brelsfoard, Kathryn E. Saatman

Spinal Cord and Brain Injury Research Center Faculty Publications

Millions of mild traumatic brain injuries (TBIs) occur every year in the United States, with many people subject to multiple head injuries that can lead to chronic behavioral dysfunction. We previously reported that mild TBI induced using closed head injuries (CHI) repeated at 24h intervals produced more acute neuron death and glial reactivity than a single CHI, and increasing the length of time between injuries to 48h reduced the cumulative acute effects of repeated CHI. To determine whether repeated CHI is associated with behavioral dysfunction or persistent cellular damage, mice receiving either five CHI at 24h intervals, five CHI at …

Behavioral And Morphological Parameters Of Neurons Predict The Inhibitory Potential Of Cspg Motifs: A Novel Technique, Edward Matin Kobraei

Kaleidoscope

Our lab aims to systematically identify the structural elements of chondroitin sulfate proteoglycans (CSPGs) that inhibit regeneration following spinal cord injury (SCI). CSPGs are extracellular matrix molecules produced by astrocytes of glial scar tissue following SCI. Central to this project is the use of CSPGs referred to as “Designer PGs,” which contain engineered modifications in the GAG chains and/ or the protein core of the neural CSPG aggrecan. Using established bioassays in vitro, we qualitatively and quantitatively measure growth cone behaviors and morphology as they interact with Designer PG molecules. These measurements are then translated into a composite inhibitory quotient …

Taranis Functions With Cyclin A And Cdk1 In A Novel Arousal Center To Control Sleep In Drosophila., Dinis J.S. Afonso, Die Liu, Daniel R. Machado, Huihui Pan, James E.C. Jepson, Dragana Rogulja, Kyunghee Koh

Department of Neuroscience Faculty Papers

Sleep is an essential and conserved behavior whose regulation at the molecular and anatomical level remains to be elucidated. Here, we identify TARANIS (TARA), a Drosophila homolog of the Trip-Br (SERTAD) family of transcriptional coregulators, as a molecule that is required for normal sleep patterns. Through a forward-genetic screen, we isolated tara as a novel sleep gene associated with a marked reduction in sleep amount. Targeted knockdown of tara suggests that it functions in cholinergic neurons to promote sleep. tara encodes a conserved cell-cycle protein that contains a Cyclin A (CycA)-binding homology domain. TARA regulates CycA protein levels and genetically …

Dysregulation Of Kv3.4 Channels In Dorsal Root Ganglia Following Spinal Cord Injury., David Ritter, Benjamin M Zemel, Tamara J Hala, Michael E O'Leary, Angelo C Lepore, Manuel Covarrubias

Farber Institute for Neuroscience Faculty Papers

Spinal cord injury (SCI) patients develop chronic pain involving poorly understood central and peripheral mechanisms. Because dysregulation of the voltage-gated Kv3.4 channel has been implicated in the hyperexcitable state of dorsal root ganglion (DRG) neurons following direct injury of sensory nerves, we asked whether such a dysregulation also plays a role in SCI. Kv3.4 channels are expressed in DRG neurons, where they help regulate action potential (AP) repolarization in a manner that depends on the modulation of inactivation by protein kinase C (PKC)-dependent phosphorylation of the channel's inactivation domain. Here, we report that, 2 weeks after cervical hemicontusion SCI, injured …

Expression Of Mir-15/107 Family Micrornas In Human Tissues And Cultured Rat Brain Cells, Wang-Xia Wang, Robert J. Danaher, Craig S. Miller, Joseph R. Berger, Vega G. Nubia, Bernard R. Wilfred, Janna H. Neltner, Christopher M. Norris, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

The miR-15/107 family comprises a group of 10 paralogous microRNAs (miRNAs), sharing a 5' AGCAGC sequence. These miRNAs have overlapping targets. In order to characterize the expression of miR-15/107 family miRNAs, we employed customized TaqMan Low-Density micro-fluid PCR-array to investigate the expression of miR-15/107 family members, and other selected miRNAs, in 11 human tissues obtained at autopsy including the cerebral cortex, frontal cortex, primary visual cortex, thalamus, heart, lung, liver, kidney, spleen, stomach and skeletal muscle. miR-103, miR-195 and miR-497 were expressed at similar levels across various tissues, whereas miR-107 is enriched in brain samples. We also examined the expression …

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 …

Synchronous And Asynchronous Theta And Gamma Activity During Episodic Memory Formation., John F Burke, Kareem A Zaghloul, Joshua Jacobs, Ryan B Williams, Michael R Sperling, Ashwini D Sharan, Michael J Kahana

Department of Neuroscience Faculty Papers

To test the hypothesis that neural oscillations synchronize to mediate memory encoding, we analyzed electrocorticographic recordings taken as 68 human neurosurgical patients studied and subsequently recalled lists of common words. To the extent that changes in spectral power reflect synchronous oscillations, we would expect those power changes to be accompanied by increases in phase synchrony between the region of interest and neighboring brain areas. Contrary to the hypothesized role of synchronous gamma oscillations in memory formation, we found that many key regions that showed power increases during successful memory encoding also exhibited decreases in global synchrony. Similarly, cortical theta activity …

Egr-1 Induces Darpp-32 Expression In Striatal Medium Spiny Neurons Via A Conserved Intragenic Element., Serene Keilani, Samira Chandwani, Georgia Dolios, Alexey Bogush, Heike Beck, Antonis K Hatzopoulos, Gadiparthi N Rao, Elizabeth A Thomas, Rong Wang, Michelle E Ehrlich

Farber Institute for Neuroscience Faculty Papers

DARPP-32 (dopamine and adenosine 3', 5'-cyclic monophosphate cAMP-regulated phosphoprotein, 32 kDa) is a striatal-enriched protein that mediates signaling by dopamine and other first messengers in the medium spiny neurons. The transcriptional mechanisms that regulate striatal DARPP-32 expression remain enigmatic and are a subject of much interest in the efforts to induce a striatal phenotype in stem cells. We report the identification and characterization of a conserved region, also known as H10, in intron IV of the gene that codes for DARPP-32 (Ppp1r1b). This DNA sequence forms multiunit complexes with nuclear proteins from adult and embryonic striata of mice and rats. …

Interaction Of The Mu-Opioid Receptor With Gpr177 (Wntless) Inhibits Wnt Secretion: Potential Implications For Opioid Dependence., Jay Jin, Saranya Kittanakom, Victoria Wong, Beverly A S Reyes, Elisabeth J Van Bockstaele, Igor Stagljar, Wade Berrettini, Robert Levenson

Department of Neurosurgery Faculty Papers

BACKGROUND: Opioid agonist drugs produce analgesia. However, long-term exposure to opioid agonists may lead to opioid dependence. The analgesic and addictive properties of opioid agonist drugs are mediated primarily via the mu-opioid receptor (MOR). Opioid agonists appear to alter neuronal morphology in key brain regions implicated in the development of opioid dependence. However, the precise role of the MOR in the development of these neuronal alterations remains elusive. We hypothesize that identifying and characterizing novel MOR interacting proteins (MORIPs) may help to elucidate the underlying mechanisms involved in the development of opioid dependence. RESULTS: GPR177, the mammalian ortholog of Drosophila …

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 …

Human Amniotic Fluid Stem Cells Do Not Differentiate Into Dopamine Neurons In Vitro Or After Transplantation In Vivo., Angela E Donaldson, Jingli Cai, Ming Yang, Lorraine Iacovitti

Farber Institute for Neuroscience Faculty Papers

Although embryonic stem (ES) cells can generate dopamine (DA) neurons that are potentially useful as a cell replacement therapy in Parkinson's disease (PD), associated ethical and practical concerns remain major stumbling blocks to their eventual use in humans. In this study, we examined human amniotic fluid stem (hAFS) cells derived from routine amniocenteses for their potential to give rise to DA neurons in vitro and following transplantation into the 6-hydroxydopamine-lesioned rat brain. We show that undifferentiated hAFS cells constitutively expressed mRNAs and proteins typical of stem cells but also cell derivatives of all three germ layers, including neural progenitors/neurons (nestin, …

Prion Protein Glycosylation Is Not Required For Strain-Specific Neurotropism, Justin R. Piro, Brent T. Harris, Koren Nishina, Claudio Soto, Rodrigo Morales, Judy R. Rees, Surachai Supattapone

Dartmouth Scholarship

In this study, we tested the hypothesis that the glycosylation of the pathogenic isoform of the prion protein (PrP^Sc) might encode the selective neurotropism of prion strains. We prepared unglycosylated cellular prion protein (PrP^C) substrate molecules from normal mouse brain by treatment with PNGase F and used reconstituted serial protein cyclic misfolding amplification reactions to produce RML and 301C mouse prions containing unglycosylated PrP^Sc molecules. Both RML- and 301C-derived prions containing unglycosylated PrP^Sc molecules were infectious to wild-type mice, and neuropathological analysis showed that mice inoculated with these samples maintained strain-specific patterns of PrP …

Idiopathic Epilepsy Of Childhood And Potassium Ion Channels, Alper I. Dai, Mohammad Wasay

Department of Medicine

Potassium can affect the development of common seizure type and can be defined seizure susceptibility allele. The existence of inward-rectifying potassium (Kir) channels was first recognized half a century ago. The biophysical fingerprint of Kir channels is inward rectification in the current-voltage relationship , which limits potassium efflux at depolarizing membrane potentials. Kir channels are essential in the control of resting membrane potential, coupling of the metabolic cellular state with membrane excitability, and maintenance of potassium homeostasis. The critical interval contains several candidate genes, one of which, KCNJ10, exhibits a potentially important polymorphism with regard to fundamental aspects of seizure …

Hypoxic Preconditioning Of Embryonic Stem Cells: A Novel Transplantation Strategy To Improve Recovery After Stroke, Michelle Hedrick Theus

MUSC Theses and Dissertations

Embryonic stem (ES) cell transplantation therapy offers a novel therapeutic alternative for ameliorating the pathologic consequences of cerebral ischemia. The success of ES cell transplantation therapy relies not only on initial survival in the post-ischemic brain but also on whether or not these cells will reliably differentiate into the appropriate neuronal phenotypes required for cerebral repair. To address both issues, the present study investigates the neural differentiation of retinoic acid treated ES cells and how activating signaling pathways common in response to hypoxia can impact their usefulness as graft material intended to repair, replace and restore function after stroke. These …

Estrogen Protects Against The Synergistic Toxicity By Hiv Proteins, Methamphetamine And Cocaine, Jadwiga Turchan, Caroline Anderson, Kurt F. Hauser, Qinmiao Sun, Jiayou Zhang, Ying Liu, Phyllis M. Wise, Inna Kruman, William Maragos, Mark P. Mattson, Rosemarie Booze, Avindra Nath

Neurology Faculty Publications

BACKGROUND: Human immunodeficiency virus (HIV) infection continues to increase at alarming rates in drug abusers, especially in women. Drugs of abuse can cause long-lasting damage to the brain and HIV infection frequently leads to a dementing illness. To determine how these drugs interact with HIV to cause CNS damage, we used an in vitro human neuronal culture characterized for the presence of dopaminergic receptors, transporters and estrogen receptors. We determined the combined effects of dopaminergic drugs, methamphetamine, or cocaine with neurotoxic HIV proteins, gp120 and Tat.

RESULTS: Acute exposure to these substances resulted in synergistic neurotoxic responses as measured by …