Medicine and Health Sciences Commons^™

Repeated Exposure To Chlorpyrifos Is Associated With A Dose-Dependent Chronic Neurobehavioral Deficit In Adult Rats, Ana C. R. Ribeiro, Elisa Hawkins, Fay M. Jahr, Joseph L. Mcclay, Laxmikant Deshpande

Neurology Publications

Organophosphate (OP) chemicals include commonly used pesticides and chemical warfare agents, and mechanistically they are potent inhibitors of the cholinesterase (ChE) enzyme. Epidemiological studies report long-term neuropsychiatric issues, including depression and cognitive impairments in OP-exposed individuals. Chlorpyrifos (CPF) is one of the most widely used pesticides worldwide. Multiple laboratory studies have reported on either the long-term behavioral effect of an acute high-dose CPF (30-250 mg/kg) or studied sub-chronic behavioral effects, particularly the motor and cognitive effects of repeated low-dose CPF. However, studies are lacking on chronic mood and depression-related morbidities following repeated CPF doses that would mimic occupationally relevant OP …

Epigenetic Histone Acetylation And Bdnf Dysregulation In The Hippocampus Of Rats Exposed To Repeated, Low-Dose Diisopropylfluorophosphate, Laxmikant Deshpande

Neurology Publications

Aims: Deployment-related exposures to organophosphate (OP) compounds are implicated for Gulf War Illness (GWI) development in First GW veterans. However, reasons for the persistence of GWI are not fully understood. Epigenetic modifications to chromatin are regulatory mechanisms that can adaptively or maladaptively respond to external stimuli. These include DNA methylation and histone acetylation. DNA methylation changes have been reported in GWI but the role of histone acetylation in GWI has been less explored, despite its importance as an epigenetic mechanism for neurological disorders.

Main methods: Male Sprague-Dawley rats were exposed to OP diisopropyl fluorophosphate (DFP, 0.5 mg/kg s.c., 5-d) and …

Targeting Intracellular Calcium Stores Alleviates Neurological Morbidities In A Dfp-Based Rat Model Of Gulf War Illness, Laxmikant Deshpande, Edna Santos, Kristin Phillips, Robert Blair

Neurology Publications

Gulf War Illness (GWI) is a chronic multi-symptom disorder afflicting the veterans of the First Gulf War, and includes neurological symptoms characterized by depression and memory deficits. Chronic exposure to organophosphates (OP) is considered a leading cause for GWI, yet its pathobiology is not fully understood. We recently observed chronic elevations in neuronal Ca2+ levels ([Ca2+]i) in an OP- diisopropyl fluorophosphate (DFP) based rat model for GWI. This study was aimed at identifying mechanisms underlying elevated [Ca2+]i in this DFP model and investigating whether their therapeutic targeting could improve GWI-like neurological morbidities. Male Sprague-Dawley rats (9-wks) were exposed to DFP …

Training Neurodegenerative Disease Support Group Leaders: A New Support Group Functioning Scale, Therese V. Cash, Christopher Kilbourn, Sarah K. Lageman

Neurology Publications

Support group leaders play pivotal roles in maintaining healthy community support groups; however, these leaders also have personal support needs and typically lack formal training in managing complex behaviors of neurodegenerative disorders. A support group well-being questionnaire, assessing support group functioning, was developed and piloted among participants of an educational training program designed for support group leaders of various neurodegenerative disorder-specific support groups. An exploratory factor analysis evaluated the questionnaire’s psychometric properties and identified a reliable single factor five-item solution, which was titled the Support Group Functioning Scale (SGFS). Preliminary interpretation guidelines were proposed. Development of this scale is a …

A Chromosomal Deletion And New Frameshift Mutation Cause Arsacs In An African-American, Sean C. Dougherty, Amy Harper, Hind Al Saif, Gregory Vorona, Scott R. Haines

Neurology Publications

Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) is a rare, progressive, neurodegenerative disease characterized by ataxia, spasticity and polyneuropathy. First described in the French-Canadian population of Quebec in 1978, ARSACS has since been identified in multiple patients worldwide. In this clinical case report, we describe the evaluation of an 11-years-old African-American male who presented to neuromuscular clinic for assessment of a gait abnormality. He had a history of gross motor delay since early childhood, frequent falls and a below average IQ. Chromosomal microarray revealed a 1.422 megabase loss in the 13q12.12 region, which includes the SACS gene. Next Generation Sequencing …

Aapt Diagnostic Criteria For Chronic Sickle Cell Disease Pain, Carlton Dampier, Tonya M. Palermo, Deepika S. Darbari, Kathryn Hassell, Wally Smith, William Zempsky

Neurology Publications

Pain in sickle cell disease (SCD) is associated with increased morbidity, mortality, and high health care costs. Although episodic acute pain is the hallmark of this disorder, there is an increasing awareness that chronic pain is part of the pain experience of many older adolescents and adults. A common set of criteria for classifying chronic pain associated with SCD would enhance SCD pain research efforts in epidemiology, pain mechanisms, and clinical trials of pain management interventions, and ultimately improve clinical assessment and management. As part of the collaborative effort between the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities …

Repeated Low-Dose Organophosphate Dfp Exposure Leads To The Development Of Depression And Cognitive Impairment In A Rat Model Of Gulf War Illness, Laxmikant Deshpande, Kristin Phillips

Neurology Publications

Approximately 175,000 to 250,000 of the returning veterans from the 1991 Persian Gulf War exhibit chronic multi-symptom illnesses that includes neurologic co-morbidities such as depression, anxiety and cognitive impairments. Amongst a host of causative factors, exposure to low levels of the nerve agent Sarin has been strongly implicated for expression of Gulf War Illness (GWI). Nerve agents similar to pesticides are organophosphate (OP) compounds. There is evidence from civilian population that exposure to OPs such as in agricultural workers and nerve agents such as the survivors and first-responders of the Tokyo subway Sarin gas attack suffer from chronic neurological problems …

Role Of The Calcium Plateau In The Neuronal Injury And Behavioral Morbidities Following Organophosphate Intoxication, Laxmikant S. Deshpande, Robert E. Blair, Kristin F. Phillips, Robert J. Delorenzo

Neurology Publications

Organophosphate (OP) chemicals include nerve agents and pesticides, and there is a growing concern of OP based chemical attacks against civilians. Current antidotes are essential in limiting immediate mortality associated with OP exposure. However, further research is needed to identify molecular mechanisms underlying long-term neurological deficits following survival of OP toxicity in order to develop effective therapeutics. We have developed rat survival models of OP induced status epilepticus (SE) that mimic chronic mortality and morbidity following OP intoxication. We have observed significant elevations in hippocampal calcium levels after OP SE that persisted for weeks following initial survival. Drugs inhibiting intracellular …

Cannabinoid Receptor Interacting Protein Suppresses Agonist-Driven Cb1 Receptor Internalization And Regulates Receptor Replenishment In An Agonist-Biased Manner, Lawrence C. Blumes, Sandra Leone-Kabler, Deborah J. Luessen, Glenn S. Marrs, Erica Lyons, Caroline E. Bass, Rong Chen, Dana E. Selley, Allyn C. Howlett

Neurology Publications

Cannabinoid receptor interacting protein 1a (CRIP1a) is a CB1 receptor (CB1R) distal C-terminus-associated protein that modulates CB1R signaling via G proteins, and CB1R down-regulation but not desensitization (Blume et al. [2015] Cell Signal., 27, 716-726; Smith et al. [2015] Mol. Pharmacol., 87, 747-765). In this study, we determined the involvement of CRIP1a in CB1R plasma membrane trafficking. To follow the effects of agonists and antagonists on cell surface CB(1)Rs, we utilized the genetically homogeneous cloned neuronal cell line N18TG2, which endogenously expresses both CB1R and CRIP1a, and exhibits a well-characterized endocannabinoid signaling system. We developed stable CRIP1a-over-expressing and CRIP1a-siRNA-silenced knockdown …

Pharmacological Blockade Of The Calcium Plateau Provides Neuroprotection Following Organophosphate Paraoxon Induced Status Epilepticus In Rats, Laxmikant S. Deshpande, Robert E. Blair, Beverly A. Huang, Kristin F. Phillips, Robert J. Delorenzo

Neurology Publications

Organophosphate (OP) compounds which include nerve agents and pesticides are considered chemical threat agents. Currently approved antidotes are crucial in limiting OP mediated acute mortality. However, survivors of lethal OP exposure exhibit delayed neuronal injury and chronic behavioral morbidities. In this study, we investigated neuroprotective capabilities of dantrolene and carisbamate in a rat survival model of paraoxon (POX) induced status epilepticus (SE). Significant elevations in hippocampal calcium levels were observed 48-h post POX SE survival, and treatment with dantrolene (10 mg/kg, i.m.) and carisbamate (90 mg/kg, i.m.) lowered these protracted calcium elevations. POX SE induced delayed neuronal injury …

Progressive Cognitive Deficit, Motor Impairment And Striatal Pathology In A Transgenic Huntington Disease Monkey Model From Infancy To Adulthood, Anthony W. S. Chan, Jie Jiang, Yiju Chen, Chunxia Li, Melinda S. Prucha, Yijuan Hu, Tim Chi, Sean Moran, Tayeb Rahim, Shihua Li, Xiaojiang Li, Stuart M. Zola, Claudia M. Testa, Hui Mao, Rosa Villalba, Yoland Smith, Xiaodong Zhang, Jocelyne Bachevalier

Neurology Publications

One of the roadblocks to developing effective therapeutics for Huntington disease (HD) is the lack of animal models that develop progressive clinical traits comparable to those seen in patients. Here we report a longitudinal study that encompasses cognitive and motor assessment, and neuroimaging of a group of transgenic HD and control monkeys from infancy to adulthood. Along with progressive cognitive and motor impairment, neuroimaging revealed a progressive reduction in striatal volume. Magnetic resonance spectroscopy at 48 months of age revealed a decrease of N-acetylaspartate (NAA), further suggesting neuronal damage/loss in the striatum. Postmortem neuropathological analyses revealed significant neuronal loss in …

Liver X Receptor-Dependent Inhibition Of Microglial Nitric Oxide Synthase 2, Julie R Secor Mcvoy, Hanadi Ajam Oughli, Unsong Oh

Neurology Publications

Background

The nuclear receptor liver X receptor (LXR) exerts transcriptional control over lipid metabolism and inflammatory response in cells of the myeloid lineage, suggesting that LXR may be a potential target in a number of chronic neuroinflammatory and neurodegenerative diseases where persistent microglial activation has been implicated in the pathogenesis.

Methods

The effect of LXR activation on microglia and central nervous system (CNS) inflammation was studied using a synthetic LXR agonist in cultured microglia, a microglial cell line and experimental allergic encephalomyelitis (EAE), an animal model of CNS inflammation.

Results

LXR activation inhibited nitric oxide synthase 2, inducible (Nos2 …

Development Of Status Epilepticus, Sustained Calcium Elevations And Neuronal Injury In A Rat Survival Model Of Lethal Paraoxon Intoxication, Laxmikant Sudhir Deshpande, Dawn S. Carter, Kristin Phillips, Robert E. Blair, Robert J. Delorenzo

Neurology Publications

Paraoxon (POX) is an active metabolite of organophosphate (OP) pesticide parathion that has been weaponized and used against civilian populations. Exposure to POX produces high mortality. OP poisoning is often associated with chronic neurological disorders. In this study, we optimize a rat survival model of lethal POX exposures in order to mimic both acute and long-term effects of POX intoxication. Male Sprague–Dawley rats injected with POX (4 mg/kg, ice-cold PBS, s.c.) produced a rapid cholinergic crisis that evolved into status epilepticus (SE) and death within 6–8 min. The EEG profile for POX induced SE was characterized and showed clinical and …

Chronic Behavioral And Cognitive Deficits In A Rat Survival Model Of Paraoxon Toxicity, Laxmikant Sudhir Deshpande, Kristin Phillips, Beverly Huang, Robert J. Delorenzo

Neurology Publications

Organophosphate (OP) compounds, including paraoxon (POX), are similar to nerve agents such as sarin. There is a growing concern that OP agents could be weaponized to cause mass civilian causalities. We have developed a rodent survival model of POX toxicity that is being used to evaluate chronic morbidity and to screen for medical countermeasures against severe OP exposure. It is well known that the survivors of nerve gas and chronic OP exposure exhibit neurobehavioral deficits such as mood changes, depression, and memory impairments. In this study we investigated whether animals surviving severe POX exposure exhibited long-term neurological impairments. POX exposure …

Mitochondrial Dna Copy Numbers In Pyramidal Neurons Are Decreased And Mitochondrial Biogenesis Transcriptome Signaling Is Disrupted In Alzheimer’S Disease Hippocampi, Ann C. Rice, Paula M. Keeney, Norah K. Algarzae, Amy C. Ladd, Ravindar R. Thomas, James P. Bennett

Neurology Publications

Alzheimer's disease (AD) is the major cause of adult-onset dementia and is characterized in its pre-diagnostic stage by reduced cerebral cortical glucose metabolism and in later stages by reduced cortical oxygen uptake, implying reduced mitochondrial respiration. Using quantitative PCR we determined the mitochondrial DNA (mtDNA) gene copy numbers from multiple groups of 15 or 20 pyramidal neurons, GFAP(+) astrocytes and dentate granule neurons isolated using laser capture microdissection, and the relative expression of mitochondrial biogenesis (mitobiogenesis) genes in hippocampi from 10 AD and 9 control (CTL) cases. AD pyramidal but not dentate granule neurons had significantly reduced mtDNA copy numbers …

Genetic Analysis Of The Neurosteroid Deoxycorticosterone And Its Relation To Alcohol Phenotypes: Identification Of Qtls And Downstream Gene Regulation, Patrizia Porcu, Todd K. O'Buckley, Soomin C. Song, Jo Lynne Harenza, Lu Lu, Xusheng Wang, Michael F. Miles, A. Leslie Morrow

Neurology Publications

Background

Deoxycorticosterone (DOC) is an endogenous neurosteroid found in brain and serum, precursor of the GABAergic neuroactive steroid (3α,5α)-3,21-dihydroxypregnan-20-one (tetrahydrodeoxycorticosterone, THDOC) and the glucocorticoid corticosterone. These steroids are elevated following stress or ethanol administration, contribute to ethanol sensitivity, and their elevation is blunted in ethanol dependence.

Methodology/Principal Findings

To systematically define the genetic basis, regulation, and behavioral significance of DOC levels in plasma and cerebral cortex we examined such levels across 47 young adult males from C57BL/6J (B6)×DBA/2J (D2) (BXD) mouse strains for quantitative trait loci (QTL) and bioinformatics analyses of behavior and gene regulation. Mice were injected with saline …

A Comparison Of Rectal Diazepam Gel And Placebo For Acute Repetitive Seizures, Fritz E. Dreifuss , M.D., N. Paul Rosman , M.D., James C. Cloyd , Pharm.D., John M. Pellock , M.D., Ruben I. Kuzniecky , M.D., Warren D. Lo , M.D., Fumisuke Matsuo , M.D., Gregory B. Sharp , M.D., Joan A. Conry , M.D., Donna C. Bergen , M.D., Walter E. Bell , Ph.D

Neurology Publications

ABSTRACT

Background Acute repetitive seizures are readily recognizable episodes involving increased seizure frequency. Urgent treatment is often required. Rectal diazepam gel is a promising therapy.

Methods We conducted a randomized, doubleblind, parallel-group, placebo-controlled study of home-based treatment for acute repetitive seizures. Patients were randomly assigned to receive either rectal diazepam gel, at doses ranging from 0.2 to 0.5 mg per kilogram of body weight on the basis of age, or placebo. Children received one dose at the onset of acute repetitive seizures and a second dose four hours later. Adults received three doses — one dose at onset, and two …

Periodic Lateralized Epileptiform Discharges, Nathan Watemberg , M.D., Lawrence D. Morton , M.D.

Neurology Publications

No abstract provided.