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Dysexecutive Difficulty And Subtle Everyday Functional Disabilities: The Digital Trail Making Test, David J Libon, Rod Swenson, Sean Tobyne, Ali Jannati, Daniel Schulman, Catherine C Price, Melissa Lamar, Alvaro Pascual-Leone Apr 2024

Dysexecutive Difficulty And Subtle Everyday Functional Disabilities: The Digital Trail Making Test, David J Libon, Rod Swenson, Sean Tobyne, Ali Jannati, Daniel Schulman, Catherine C Price, Melissa Lamar, Alvaro Pascual-Leone

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

BACKGROUND: Digital neuropsychological tests reliably capture real-time, process-based behavior that traditional paper/pencil tests cannot detect, enabling earlier detection of neurodegenerative illness. We assessed relations between informant-based subtle and mild functional decline and process-based features extracted from the digital Trail Making Test-Part B (dTMT-B).

METHODS: A total of 321 community-dwelling participants (56.0% female) were assessed with the Functional Activities Questionnaire (FAQ) and the dTMT-B. Three FAQ groups were constructed: FAQ = 0 (unimpaired); FAQ = 1-4 (subtle impairment); FAQ = 5-8 (mild impairment).

Results: Compared to the FAQ-unimpaired group, other groups required longer pauses inside target circles (p < 0.050) and produced more total pen strokes to complete the test (p < 0.016). FAQ-subtle participants required more time to complete the entire test (p …


Comparing Cognitive Tests And Smartphone-Based Assessment In 2 Us Community-Based Cohorts., Ileana De Anda-Duran, Preeti Sunderaraman, Edward Searls, Shirine Moukaled, Xuanyi Jin, Zachary Popp, Cody Karjadi, Phillip H Hwang, Huitong Ding, Sherral Devine, Ludy C Shih, Spencer Low, Honghuang Lin, Vijaya B Kolachalama, Lydia Bazzano, David J Libon, Rhoda Au Jan 2024

Comparing Cognitive Tests And Smartphone-Based Assessment In 2 Us Community-Based Cohorts., Ileana De Anda-Duran, Preeti Sunderaraman, Edward Searls, Shirine Moukaled, Xuanyi Jin, Zachary Popp, Cody Karjadi, Phillip H Hwang, Huitong Ding, Sherral Devine, Ludy C Shih, Spencer Low, Honghuang Lin, Vijaya B Kolachalama, Lydia Bazzano, David J Libon, Rhoda Au

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

BACKGROUND: Smartphone-based cognitive assessments have emerged as promising tools, bridging gaps in accessibility and reducing bias in Alzheimer disease and related dementia research. However, their congruence with traditional neuropsychological tests and usefulness in diverse cohorts remain underexplored.

METHODS AND RESULTS: A total of 406 FHS (Framingham Heart Study) and 59 BHS (Bogalusa Heart Study) participants with traditional neuropsychological tests and digital assessments using the Defense Automated Neurocognitive Assessment (DANA) smartphone protocol were included. Regression models investigated associations between DANA task digital measures and a neuropsychological global cognitive

CONCLUSIONS: Our findings demonstrate that smartphone-based cognitive assessments exhibit concurrent validity with a …


Nucleus Accumbens Core Single Cell Ensembles Bidirectionally Respond To Experienced Versus Observed Aversive Events, Oyku Dinckol, Noah Harris Wenger, Jennifer E Zachry, Munir Gunes Kutlu Dec 2023

Nucleus Accumbens Core Single Cell Ensembles Bidirectionally Respond To Experienced Versus Observed Aversive Events, Oyku Dinckol, Noah Harris Wenger, Jennifer E Zachry, Munir Gunes Kutlu

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Fear learning is a critical feature of survival skills among mammals. In rodents, fear learning manifests itself through direct experience of the aversive event or social transmission of aversive stimuli such as observing and acting on conspecifics' distress. The neuronal network underlying the social transmission of information largely overlaps with the brain regions that mediate behavioral responses to aversive and rewarding stimuli. In this study, we recorded single cell activity patterns of nucleus accumbens (NAc) core neurons using in vivo optical imaging of calcium transients via miniature scopes. This cutting-edge imaging methodology not only allows us to record activity patterns …


Editorial: Sex Differences In The Neurobiology Of Drug Relapse Vulnerability, Daniel F Manvich, Jessica A Loweth, Wendy J Lynch, Jayme R Mcreynolds Sep 2023

Editorial: Sex Differences In The Neurobiology Of Drug Relapse Vulnerability, Daniel F Manvich, Jessica A Loweth, Wendy J Lynch, Jayme R Mcreynolds

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

No abstract provided.


Bisphenol-A And Phthalate Metabolism In Children With Neurodevelopmental Disorders, T Peter Stein, Margaret D Schluter, Robert A Steer, Xue Ming Sep 2023

Bisphenol-A And Phthalate Metabolism In Children With Neurodevelopmental Disorders, T Peter Stein, Margaret D Schluter, Robert A Steer, Xue Ming

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

BACKGROUND: The etiology of autism spectrum (ASD) and Attention Deficit/Hyperactivity (ADHD) disorders are multifactorial. Epidemiological studies have shown associations with environmental pollutants, such as plasticizers. This study focused on two of these compounds, the Bisphenol-A (BPA) and Diethylhexyl Phthalate (DEHP). The major pathway for BPA and DEHP excretion is via glucuronidation. Glucuronidation makes insoluble substances more water-soluble allowing for their subsequent elimination in urine.

HYPOTHESIS: Detoxification of these two plasticizers is compromised in children with ASD and ADHD. Consequently, their tissues are more exposed to these two plasticizers.

METHODS: We measured the efficiency of glucuronidation in three groups of children, …


Effects Of Sex And Estrous Cycle On Intravenous Oxycodone Self-Administration And The Reinstatement Of Oxycodone-Seeking Behavior In Rats, Nicole M. Hinds, Ireneusz D. Wojtas, Corinne A. Gallagher, Claire M. Corbett, Daniel F. Manvich Jul 2023

Effects Of Sex And Estrous Cycle On Intravenous Oxycodone Self-Administration And The Reinstatement Of Oxycodone-Seeking Behavior In Rats, Nicole M. Hinds, Ireneusz D. Wojtas, Corinne A. Gallagher, Claire M. Corbett, Daniel F. Manvich

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

The increasing misuse of both prescription and illicit opioids has culminated in a national healthcare crisis in the United States. Oxycodone is among the most widely prescribed and misused opioid pain relievers and has been associated with a high risk for transition to compulsive opioid use. Here, we sought to examine potential sex differences and estrous cycle-dependent effects on the reinforcing efficacy of oxycodone, as well as on stress-induced or cue-induced oxycodone-seeking behavior, using intravenous (IV) oxycodone self-administration and reinstatement procedures. In experiment 1, adult male and female Long-Evans rats were trained to self-administer 0.03 mg/kg/inf oxycodone according to a …


Mglu5 Inhibition In The Basolateral Amygdala Prevents Estrous Cycle-Dependent Changes In Cue-Induced Cocaine Seeking, Claire M. Corbett, Emily N. D. Miller, Jessica A. Loweth Mar 2023

Mglu5 Inhibition In The Basolateral Amygdala Prevents Estrous Cycle-Dependent Changes In Cue-Induced Cocaine Seeking, Claire M. Corbett, Emily N. D. Miller, Jessica A. Loweth

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Drug associated cues are a common relapse trigger for individuals recovering from cocaine use disorder. Sex and ovarian hormones influence patterns of cocaine use and relapse vulnerability, with studies indicating that females show increased cue-induced craving and relapse vulnerability compared to males. In a rodent model of cocaine craving and relapse vulnerability, cue-induced cocaine seeking behavior following weeks of withdrawal from extended-access cocaine self-administration is higher in females in the estrus stage of the reproductive (estrous) cycle (Estrus Females) compared to both Males and females in all other stages (Non-Estrus Females). However, the neuronal substrates and cellular mechanisms underlying these …


Neural Substrates Of Homing Pigeon Spatial Navigation: Results From Electrophysiology Studies, Gerald E. Hough Apr 2022

Neural Substrates Of Homing Pigeon Spatial Navigation: Results From Electrophysiology Studies, Gerald E. Hough

Faculty Scholarship for the College of Science & Mathematics

Over many centuries, the homing pigeon has been selectively bred for returning home from a distant location. As a result of this strong selective pressure, homing pigeons have developed an excellent spatial navigation system. This system passes through the hippocampal formation (HF), which shares many striking similarities to the mammalian hippocampus; there are a host of shared neuropeptides, interconnections, and its role in the storage and manipulation of spatial maps. There are some notable differences as well: there are unique connectivity patterns and spatial encoding strategies. This review summarizes the comparisons between the avian and mammalian hippocampal systems, and the …


Deficiency Of Complement Component C1q Prevents Cerebrovascular Damage And White Matter Loss In A Mouse Model Of Chronic Obesity., Leah C Graham, Heidi E Kocalis, Ileana Soto Reyes, Gareth R Howell May 2020

Deficiency Of Complement Component C1q Prevents Cerebrovascular Damage And White Matter Loss In A Mouse Model Of Chronic Obesity., Leah C Graham, Heidi E Kocalis, Ileana Soto Reyes, Gareth R Howell

Faculty Scholarship for the College of Science & Mathematics

Age-related cognitive decline and many dementias involve complex interactions of both genetic and environmental risk factors. Recent evidence has demonstrated a strong association of obesity with the development of dementia. Furthermore, white matter damage is found in obese subjects and mouse models of obesity. Here, we found that components of the complement cascade, including complement component 1qa (C1QA) and C3 are increased in the brain of Western diet (WD)-fed obese mice, particularly in white matter regions. To functionally test the role of the complement cascade in obesity-induced brain pathology, female and male mice deficient in C1QA, an essential molecule in …


Visual And Verbal Serial List Learning In Patients With Statistically-Determined Mild Cognitive Impairment., Victor Wasserman, Sheina Emrani, Emily F Matusz, David Miller, Kelly Davis Garrett, Katherine A Gifford, Timothy J Hohman, Angela L Jefferson, Rhoda Au, Rod Swenson, David J Libon, Consortium For Clinical And Epidemiological Neuropsychological Data Analysis (Cenda). May 2019

Visual And Verbal Serial List Learning In Patients With Statistically-Determined Mild Cognitive Impairment., Victor Wasserman, Sheina Emrani, Emily F Matusz, David Miller, Kelly Davis Garrett, Katherine A Gifford, Timothy J Hohman, Angela L Jefferson, Rhoda Au, Rod Swenson, David J Libon, Consortium For Clinical And Epidemiological Neuropsychological Data Analysis (Cenda).

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Background and Objective: Prior research with patients with mild cognitive impairment (MCI) suggests that visual versus verbal episodic memory test performance may be more sensitive to emergent illness. However, little research has examined visual versus verbal episodic memory performance as related to MCI subtypes.

Research Design and Methods: Patients were diagnosed with non-MCI, amnestic MCI (aMCI), and combined mixed/dysexecutive MCI (mixed/dys MCI). Visual and verbal episodic memory were assessed with the Brief Visuospatial Memory Test-Revised (BVMT-R) and the 12-word Philadelphia (repeatable) Verbal Learning Test (P[r]VLT), respectively.

Results: BVMT-R and P(r)VLT scores yielded similar between-group patterns of performance. Non-MCI patients scored …


Antibodies In The Diagnosis, Prognosis, And Prediction Of Psychotic Disorders., Thomas A Pollak, Jonathan P Rogers, Robert G Nagele, Mark Peakman, James M Stone, Anthony S David, Philip Mcguire Jan 2019

Antibodies In The Diagnosis, Prognosis, And Prediction Of Psychotic Disorders., Thomas A Pollak, Jonathan P Rogers, Robert G Nagele, Mark Peakman, James M Stone, Anthony S David, Philip Mcguire

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Blood-based biomarker discovery for psychotic disorders has yet to impact upon routine clinical practice. In physical disorders antibodies have established roles as diagnostic, prognostic and predictive (theranostic) biomarkers, particularly in disorders thought to have a substantial autoimmune or infective aetiology. Two approaches to antibody biomarker identification are distinguished: a "top-down" approach, in which antibodies to specific antigens are sought based on the known function of the antigen and its putative role in the disorder, and emerging "bottom-up" or "omics" approaches that are agnostic as to the significance of any one antigen, using high-throughput arrays to identify distinctive components of the …


Baseline White Matter Hyperintensities And Hippocampal Volume Are Associated With Conversion From Normal Cognition To Mild Cognitive Impairment In The Framingham Offspring Study., Katherine J Bangen, Sarah R Preis, Lisa Delano-Wood, Philip A Wolf, David J Libon, Mark W Bondi, Rhoda Au, Charles Decarli, Adam M Brickman Jan 2018

Baseline White Matter Hyperintensities And Hippocampal Volume Are Associated With Conversion From Normal Cognition To Mild Cognitive Impairment In The Framingham Offspring Study., Katherine J Bangen, Sarah R Preis, Lisa Delano-Wood, Philip A Wolf, David J Libon, Mark W Bondi, Rhoda Au, Charles Decarli, Adam M Brickman

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

INTRODUCTION: We examined associations between magnetic resonance imaging (MRI) markers of cerebrovascular disease and neurodegeneration with mild cognitive impairment (MCI) diagnosis at baseline and conversion from normal cognition to MCI at follow-up.

METHODS: Framingham Offspring participants underwent brain MRI and neuropsychological assessment at baseline (n=1049) and follow-up (n=561). Participants were classified at baseline and at follow-up as cognitively normal or MCI using sensitive neuropsychological criteria. White matter hyperintensity (WMH) volume, covert brain infarcts, hippocampal volume, and total cerebral brain volume were quantified.

RESULTS: Baseline measures of WMH and hippocampal volume were associated with MCI status cross-sectionally and also with conversion …


A Gut Feeling: A Hypothesis Of The Role Of The Microbiome In Attention-Deficit/Hyperactivity Disorders., Xue Ming, Neil Chen, Carly Ray, Gretchen Brewer, Jeffrey Kornitzer, Robert A Steer Jan 2018

A Gut Feeling: A Hypothesis Of The Role Of The Microbiome In Attention-Deficit/Hyperactivity Disorders., Xue Ming, Neil Chen, Carly Ray, Gretchen Brewer, Jeffrey Kornitzer, Robert A Steer

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Attention-deficit/hyperactivity disorder (ADHD) is a neurologic disorder characterized by hyperactivity/impulsivity and/or inattentiveness, with genetic and environmental factors contributing to the disorder. With the growing recognition of the microbiome's role in many neurological disorders, the authors propose that it may also be implicated in ADHD. Here, we describe several evolving areas of research to support this hypothesis. First, a unique composition of gut bacteria has been identified and linked to behaviors in ADHD. Second, our research found an increased incidence of 2 gastrointestinal symptoms (constipation and flatulence) in children with ADHD, as compared to controls. Finally, emerging data may be interpreted …


Meox2 Haploinsufficiency Increases Neuronal Cell Loss In A Mouse Model Of Alzheimer's Disease, Ileana Soto Reyes, Weronika A. Grabowska, Kristen D. Onos, Leah C. Graham, Harriet M. Jackson, Stephen N. Simeone, Gareth R. Howell Jun 2016

Meox2 Haploinsufficiency Increases Neuronal Cell Loss In A Mouse Model Of Alzheimer's Disease, Ileana Soto Reyes, Weronika A. Grabowska, Kristen D. Onos, Leah C. Graham, Harriet M. Jackson, Stephen N. Simeone, Gareth R. Howell

Faculty Scholarship for the College of Science & Mathematics

Evidence suggests that multiple genetic and environmental factors conspire together to increase susceptibility to Alzheimer's disease (AD). The amyloid cascade hypothesis states that deposition of the amyloid-β (Aβ) peptide is central to AD; however, evidence in humans and animals suggests that Aβ buildup alone is not sufficient to cause neuronal cell loss and cognitive decline. Mouse models that express high levels of mutant forms of amyloid precursor protein and/or cleaving enzymes deposit amyloid but do not show neuron loss. Therefore, a double-hit hypothesis for AD has been proposed whereby vascular dysfunction precedes and promotes Aβ toxicity. In support of this, …


Chronic Consumption Of A Western Diet Induces Robust Glial Activation In Aging Mice And In A Mouse Model Of Alzheimer’S Disease, Leah C. Graham, Jeffrey M. Harder, Ileana Soto Reyes, Wilhelmine N. De Vries, Simon W. M. John, Gareth R. Howell Feb 2016

Chronic Consumption Of A Western Diet Induces Robust Glial Activation In Aging Mice And In A Mouse Model Of Alzheimer’S Disease, Leah C. Graham, Jeffrey M. Harder, Ileana Soto Reyes, Wilhelmine N. De Vries, Simon W. M. John, Gareth R. Howell

Faculty Scholarship for the College of Science & Mathematics

Studies have assessed individual components of a western diet, but no study has assessed the long-term, cumulative effects of a western diet on aging and Alzheimer’s disease (AD). Therefore, we have formulated the first western-style diet that mimics the fat, carbohydrate, protein, vitamin and mineral levels of western diets. This diet was fed to aging C57BL/6J (B6) mice to identify phenotypes that may increase susceptibility to AD, and to APP/PS1 mice, a mouse model of AD, to determine the effects of the diet in AD. Astrocytosis and microglia/monocyte activation were dramatically increased in response to diet and was further increased …


Apoe Stabilization By Exercise Prevents Aging Neurovascular Dysfunction And Complement Induction, Ileana Soto Reyes, Leah C. Graham, Hannah J. Richter, Stephen N. Simeone, Jake E. Radell, Weronika Grabowska, W. Keith Funkhouser, Megan C. Howell, Gareth R. Howell Oct 2015

Apoe Stabilization By Exercise Prevents Aging Neurovascular Dysfunction And Complement Induction, Ileana Soto Reyes, Leah C. Graham, Hannah J. Richter, Stephen N. Simeone, Jake E. Radell, Weronika Grabowska, W. Keith Funkhouser, Megan C. Howell, Gareth R. Howell

Faculty Scholarship for the College of Science & Mathematics

Aging is the major risk factor for neurodegenerative diseases such as Alzheimer's disease, but little is known about the processes that lead to age-related decline of brain structures and function. Here we use RNA-seq in combination with high resolution histological analyses to show that aging leads to a significant deterioration of neurovascular structures including basement membrane reduction, pericyte loss, and astrocyte dysfunction. Neurovascular decline was sufficient to cause vascular leakage and correlated strongly with an increase in neuroinflammation including up-regulation of complement component C1QA in microglia/monocytes. Importantly, long-term aerobic exercise from midlife to old age prevented this age-related neurovascular decline, …


The Cognition-Enhancing Effects Of Psychostimulants Involve Direct Action In The Prefrontal Cortex, Robert C. Spencer, David M. Devilbiss, Craig Berridge Jun 2015

The Cognition-Enhancing Effects Of Psychostimulants Involve Direct Action In The Prefrontal Cortex, Robert C. Spencer, David M. Devilbiss, Craig Berridge

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Psychostimulants are highly effective in the treatment of attention-deficit/hyperactivity disorder. The clinical efficacy of these drugs is strongly linked to their ability to improve cognition dependent on the prefrontal cortex (PFC) and extended frontostriatal circuit. The procognitive actions of psychostimulants are only associated with low doses. Surprisingly, despite nearly 80 years of clinical use, the neurobiology of the procognitive actions of psychostimulants has only recently been systematically investigated. Findings from this research unambiguously demonstrate that the cognition-enhancing effects of psychostimulants involve the preferential elevation of catecholamines in the PFC and the subsequent activation of norepinephrine α2 and dopamine D1 receptors. …


Dba/2j Mice Are Susceptible To Diabetic Nephropathy And Diabetic Exacerbation Of Iop Elevation, Ileana Soto Reyes, Gareth R. Howell, Cai W. John, Joseph L. Kief, Richard T. Libby, Simon W.M. John Sep 2014

Dba/2j Mice Are Susceptible To Diabetic Nephropathy And Diabetic Exacerbation Of Iop Elevation, Ileana Soto Reyes, Gareth R. Howell, Cai W. John, Joseph L. Kief, Richard T. Libby, Simon W.M. John

Faculty Scholarship for the College of Science & Mathematics

Some pathological manifestations of diabetes in the eye include retinopathy, cataracts and elevated intraocular pressure (IOP). Loss of retinal ganglion cells (RGCs) in non-proliferative stages of diabetic retinopathy and small increases in IOP in diabetic patients has raised the possibility that diabetes affects the development and progression of ocular hypertension and glaucoma. The Ins2Akita mutation is known to cause diabetes and retinopathy on a C57BL/6J (B6) background by as early as 3 months of age. Here, the impact of the Akita mutation on glaucoma was assessed using DBA/2J (D2) mice, a widely used mouse model of ocular hypertension induced glaucoma. …


Deficiency Of Complement Component 5 Ameliorates Glaucoma In Dba/2j Mice, Gareth R. Howell, Ileana Soto Reyes, Margaret Ryan, Leah C. Graham, Richard S. Smith, Simon W.M. John Jun 2013

Deficiency Of Complement Component 5 Ameliorates Glaucoma In Dba/2j Mice, Gareth R. Howell, Ileana Soto Reyes, Margaret Ryan, Leah C. Graham, Richard S. Smith, Simon W.M. John

Faculty Scholarship for the College of Science & Mathematics

Background Glaucoma is an age-related neurodegenerative disorder involving the loss of retinal ganglion cells (RGCs), which results in blindness. Studies in animal models have shown that activation of inflammatory processes occurs early in the disease. In particular, the complement cascade is activated very early in DBA/2J mice, a widely used mouse model of glaucoma. A comprehensive analysis of the role of the complement cascade in DBA/2J glaucoma has not been possible because DBA/2J mice are naturally deficient in complement component 5 (C5, also known as hemolytic complement, Hc), a key mediator of the downstream processes of the complement cascade, including …


Psychostimulants As Cognitive Enhancers: The Prefrontal Cortex, Catecholamines And Attention Deficit Hyperactivity Disorder, Craig Berridge, David M. Devilbiss Jun 2011

Psychostimulants As Cognitive Enhancers: The Prefrontal Cortex, Catecholamines And Attention Deficit Hyperactivity Disorder, Craig Berridge, David M. Devilbiss

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Psychostimulants exert behavioral-calming and cognition-enhancing actions in the treatment of attention deficit hyperactivity disorder (ADHD). Contrary to early views, extensive research demonstrates that these actions are not unique to ADHD. Specifically, when administered at low and clinically-relevant doses, psychostimulants improve a variety of behavioral and cognitive processes dependent on the prefrontal cortex (PFC) in subjects with and without ADHD. Despite the longstanding clinical use of these drugs, the neural mechanisms underlying their cognition-enhancing/therapeutic actions have only recently begun to be examined. At behaviorally-activating doses, psychostimulants produce large and widespread increases in extracellular levels of brain catecholamines. In contrast, cognition-enhancing doses …


Short-Term And Long-Term Effects Of Vocal Distortion On Song Maintenance In Zebra Finches, Gerald E. Hough, Susan F. Volman Feb 2002

Short-Term And Long-Term Effects Of Vocal Distortion On Song Maintenance In Zebra Finches, Gerald E. Hough, Susan F. Volman

Faculty Scholarship for the College of Science & Mathematics

Adult zebra finch song is irreversibly altered when birds are deprived of correct feedback by deafening or denervation of the syrinx. To clarify the role of feedback in song maintenance, we developed a reversible technique to distort vocal output without damaging the auditory or vocal systems. We implanted flexible beads adjacent to the syrinx to alter its biomechanics. Immediate song aberrations included low volume, frequency shifts, missing harmonics, and production of click-like syllables. After a few weeks, seven of nine birds stopped producing some syllables. In six of these birds, the gaps left by the silenced syllables gradually shortened, and …


Prolonged Cyclooxygenase-2 Induction In Neurons And Glia Following Traumatic Brain Injury In The Rat, K I Strauss, M F Barbe, R M Marshall Demarest, R Raghupathi, S Mehta, R K Narayan Aug 2000

Prolonged Cyclooxygenase-2 Induction In Neurons And Glia Following Traumatic Brain Injury In The Rat, K I Strauss, M F Barbe, R M Marshall Demarest, R Raghupathi, S Mehta, R K Narayan

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Cyclooxygenase-2 (COX2) is a primary inflammatory mediator that converts arachidonic acid into precursors of vasoactive prostaglandins, producing reactive oxygen species in the process. Under normal conditions COX2 is not detectable, except at low abundance in the brain. This study demonstrates a distinctive pattern of COX2 increases in the brain over time following traumatic brain injury (TBI). Quantitative lysate ribonuclease protection assays indicate acute and sustained increases in COX2 mRNA in two rat models of TBI. In the lateral fluid percussion model, COX2 mRNA is significantly elevated (>twofold, p < 0.05, Dunnett) at 1 day postinjury in the injured cortex and bilaterally in the hippocampus, compared to sham-injured controls. In the lateral cortical impact model (LCI), COX2 mRNA peaks around 6 h postinjury in the ipsilateral cerebral cortex (fivefold induction, p < 0.05, Dunnett) and in the ipsilateral and contralateral hippocampus (two- and six-fold induction, respectively, p < 0.05, Dunnett). Increases are sustained out to 3 days postinjury in the injured cortex in both models. Further analyses use the LCI model to evaluate COX2 induction. Immunoblot analyses confirm increased levels of COX2 protein in the cortex and hippocampus. Profound increases in COX2 protein are observed in the cortex at 1-3 days, that return to sham levels by 7 days postinjury (p < 0.05, Dunnett). The cellular pattern of COX2 induction following TBI has been characterized using immunohistochemistry. COX2-immunoreactivity (-ir) rises acutely (cell numbers and intensity) and remains elevated for several days following TBI. Increases in COX2-ir colocalize with neurons (MAP2-ir) and glia (GFAP-ir). Increases in COX2-ir are observed in cerebral cortex and hippocampus, ipsilateral and contralateral to injury as early as 2 h postinjury. Neurons in the ipsilateral parietal, perirhinal and piriform cortex become intensely COX2-ir from 2 h to at least 3 days postinjury. In agreement with the mRNA and immunoblot results, COX2-ir appears greatest in the contralateral hippocampus. Hippocampal COX2-ir progresses from the pyramidal cell layer of the CA1 and CA2 region at 2 h, to the CA3 pyramidal cells and dentate polymorphic and granule cell layers by 24 h postinjury. These increases are distinct from those observed following inflammatory challenge, and correspond to brain areas previously identified with the neurological and cognitive deficits associated with TBI. While COX2 induction following TBI may result in selective beneficial responses, chronic COX2 production may contribute to free radical mediated cellular damage, vascular dysfunction, and alterations in cellular metabolism. These may cause secondary injuries to the brain that promote neuropathology and worsen behavioral outcome.