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Articles 61 - 90 of 116

Full-Text Articles in Medical Physiology

Protein Kinase A And Epac Mediate Chronic Pain After Injury: Prolonged Inhibition By Endogenous Y1 Receptors In Dorsal Horn, Weisi Fu Jan 2016

Protein Kinase A And Epac Mediate Chronic Pain After Injury: Prolonged Inhibition By Endogenous Y1 Receptors In Dorsal Horn, Weisi Fu

Theses and Dissertations--Physiology

Inflammation or nerve injury sensitizes several populations of nociceptive neurons in the dorsal horn of the spinal cord, including those that express the neuropeptide Y (NPY) Y1 receptor (Y1R). Our overall hypothesis is that after tissue or nerve injury, these Y1R-expressing neurons enter a state of latent sensitization (LS) that contributes to vulnerability to the development of chronic pain; furthermore, LS is under the tonic inhibitory control of endogenous Y1R signaling. First, we evaluated the intracellular signaling pathways that become activated in Y1R-expressing neurons and participate in LS. To do this, we established behavioral models of inflammatory or neuropathic pain, …


Plastin 3 Expression Does Not Modify Spinal Muscular Atrophy Severity In The ∆7 Sma Mouse, Vicki L. Mcgovern, Aurelie Massoni-Laporte, Xueyong Wang, Thanh T. Le, Hao T. Le, Mark M. Rich, Arthur H. M. Burghes Jul 2015

Plastin 3 Expression Does Not Modify Spinal Muscular Atrophy Severity In The ∆7 Sma Mouse, Vicki L. Mcgovern, Aurelie Massoni-Laporte, Xueyong Wang, Thanh T. Le, Hao T. Le, Mark M. Rich, Arthur H. M. Burghes

Neuroscience, Cell Biology & Physiology Faculty Publications

Spinal muscular atrophy is caused by loss of the SMN1 gene and retention of SMN2. TheSMN2 copy number inversely correlates with phenotypic severity and is a modifier of disease outcome. The SMN2 gene essentially differs from SMN1 by a single nucleotide in exon 7 that modulates the incorporation of exon 7 into the final SMN transcript. The majority of the SMN2transcripts lack exon 7 and this leads to a SMN protein that does not effectively oligomerize and is rapidly degraded. However theSMN2 gene does produce some full-length SMN and theSMN2 copy number along with how …


Appropriate Timing Of Fluoxetine And Statin Delivery Reduces The Risk Of Secondary Bleeding In Ischemic Stroke Rats, Maria Helen Harley Balch, Moner A. Ragas, Danny Wright, Kenny Reynolds, Bryce Kerr, Adrian M. Corbett Jan 2015

Appropriate Timing Of Fluoxetine And Statin Delivery Reduces The Risk Of Secondary Bleeding In Ischemic Stroke Rats, Maria Helen Harley Balch, Moner A. Ragas, Danny Wright, Kenny Reynolds, Bryce Kerr, Adrian M. Corbett

Neuroscience, Cell Biology & Physiology Faculty Publications

Background: Ongoing clinical trials are testing the effect of fluoxetine delivered post-stroke where a majority of patients are taking statins. This study determined the influence of the timing of administration of fluoxetine and statin on the final infarct volume and the risk of secondary bleeding in an animal model of ischemic stroke.

Methods and findings: Ischemic strokes were induced by endothelin-1 injection into two cortical sites of 10-12 month old female rats, targeting the forelimb motor cortex. Combined medications (5 mg/kg fluoxetine and 1 mg/kg simvastatin) were orally administered either beginning 6-12 hours or 20-26 hours after stroke induction and …


Swimming Against The Tide: Investigations Of The C-Bouton Synapse, Adam S. Deardorff, Shannon H. Romer, Patrick M. Sonner, Robert E. W. Fyffe Sep 2014

Swimming Against The Tide: Investigations Of The C-Bouton Synapse, Adam S. Deardorff, Shannon H. Romer, Patrick M. Sonner, Robert E. W. Fyffe

Neuroscience, Cell Biology & Physiology Faculty Publications

C-boutons are important cholinergic modulatory loci for state-dependent alterations in motoneuron firing rate. m2 receptors are concentrated postsynaptic to C-boutons, and m2 receptor activation increases motoneuron excitability by reducing the action potential afterhyperpolarization. Here, using an intensive review of the current literature as well as data from our laboratory, we illustrate that C-bouton postsynaptic sites comprise a unique structural/functional domain containing appropriate cellular machinery (a “signaling ensemble”) for cholinergic regulation of outward K+ currents. Moreover, synaptic reorganization at these critical sites has been observed in a variety of pathologic states. Yet despite recent advances, there are still great challenges …


Motor Axon Synapses On Renshaw Cells Contain Higher Levels Of Aspartate Than Glutamate, Dannette Shanon Richards, Ronald W. Griffith, Shannon H. Romer, Francisco J. Alvarez May 2014

Motor Axon Synapses On Renshaw Cells Contain Higher Levels Of Aspartate Than Glutamate, Dannette Shanon Richards, Ronald W. Griffith, Shannon H. Romer, Francisco J. Alvarez

Neuroscience, Cell Biology & Physiology Faculty Publications

Motoneuron synapses on spinal cord interneurons known as Renshaw cells activate nicotinic, AMPA and NMDA receptors consistent with co-release of acetylcholine and excitatory amino acids (EAA). However, whether these synapses express vesicular glutamate transporters (VGLUTs) capable of accumulating glutamate into synaptic vesicles is controversial. An alternative possibility is that these synapses release other EAAs, like aspartate, not dependent on VGLUTs. To clarify the exact EAA concentrated at motor axon synapses we performed a quantitative postembedding colloidal gold immunoelectron analysis for aspartate and glutamate on motor axon synapses (identified by immunoreactivity to the vesicular acetylcholine transporter; VAChT) contacting calbindin-immunoreactive (-IR) Renshaw …


Adult Spinal Motoneurones Are Not Hyperexcitable In A Mouse Model Of Inherited Amyotrophic Lateral Sclerosis, Nicolas Delestrée, Marin Manuel, Caroline Iglesias, Sherif M. Elbasiouny, C. J. Heckman, Daniel Zytnicki Apr 2014

Adult Spinal Motoneurones Are Not Hyperexcitable In A Mouse Model Of Inherited Amyotrophic Lateral Sclerosis, Nicolas Delestrée, Marin Manuel, Caroline Iglesias, Sherif M. Elbasiouny, C. J. Heckman, Daniel Zytnicki

Neuroscience, Cell Biology & Physiology Faculty Publications

In amyotrophic lateral sclerosis (ALS), an adult onset disease in which there is progressive degeneration of motoneurones, it has been suggested that an intrinsic hyperexcitability of motoneurones (i.e. an increase in their firing rates), contributes to excitotoxicity and to disease onset. Here we show that there is no such intrinsic hyperexcitability in spinal motoneurones. Our studies were carried out in an adult mouse model of ALS with a mutated form of superoxide dismutase 1 around the time of the first muscle fibre denervations. We showed that the recruitment current, the voltage threshold for spiking and the frequency–intensity gain in the …


Substance P Differentially Modulates Firing Rate Of Solitary Complex (Sc) Neurons From Control And Chronic Hypoxia-Adapted Adult Rats, Nicole L. Nichols, Frank L. Powell, Jay B. Dean, Robert W. Putnam Feb 2014

Substance P Differentially Modulates Firing Rate Of Solitary Complex (Sc) Neurons From Control And Chronic Hypoxia-Adapted Adult Rats, Nicole L. Nichols, Frank L. Powell, Jay B. Dean, Robert W. Putnam

Neuroscience, Cell Biology & Physiology Faculty Publications

NK1 receptors, which bind substance P, are present in the majority of brainstem regions that contain CO2/H+-sensitive neurons that play a role in central chemosensitivity. However, the effect of substance P on the chemosensitive response of neurons from these regions has not been studied. Hypoxia increases substance P release from peripheral afferents that terminate in the caudal nucleus tractus solitarius (NTS). Here we studied the effect of substance P on the chemosensitive responses of solitary complex (SC: NTS and dorsal motor nucleus) neurons from control and chronic hypoxia-adapted (CHx) adult rats. We simultaneously measured intracellular pH …


Complexity Of Interferon-Γ Interactions With Hsv-1, Nancy J. Bigley Feb 2014

Complexity Of Interferon-Γ Interactions With Hsv-1, Nancy J. Bigley

Neuroscience, Cell Biology & Physiology Faculty Publications

The intricacies involving the role of interferon-gamma (IFN-γ) in herpesvirus infection and persistence are complex. Herpes simplex virus type 1 (HSV-1) uses a variety of receptors to enter cells and is transported to and from the host cell nucleus over the microtubule railroad via retrograde and anterograde transport. IFN-γ exerts dual but conflicting effects on microtubule organization. IFN-γ stimulates production of suppressors of cytokine signaling 1 and 3 (SOCS1 and SOCS3), which are involved in microtubule stability and are negative regulators of IFN-γ signaling when overexpressed. IFN-γ also interferes with the correct assembly of microtubules causing them to undergo severe …


Caveolins And Njks Influence Brain Endothelial Permeability After Juvenile Tbi, David Olufemi Ajao Dec 2013

Caveolins And Njks Influence Brain Endothelial Permeability After Juvenile Tbi, David Olufemi Ajao

Loma Linda University Electronic Theses, Dissertations & Projects

Disruption of blood-brain barrier (BBB) is a key secondary event that exacerbates brain damage following traumatic brain injury (TBI). BBB disruption is particularly damaging to the developing brain – which is highly vulnerable to various stress stimuli, resulting in increased brain swelling, disrupted cerebral blood flow (CBF) autoregulation, long-term disabilities and death following TBI in young demographic. Unsurprisingly, BBB disruption and the resultant cerebral edema have emerged as therapeutic targets in juvenile TBI. It is therefore important to understand the molecular players and mechanisms involved in TBI-induced BBB disruption in the juvenile brain. To this end, the endothelial caveolins and …


Nf1 Loss And Ras Hyperactivation In Oligodendrocytes Induce Nos-Driven Defects In Myelin And Vasculature, Debra A. Mayes, Tilat A. Rizvi, Haley E. Titus-Mitchell, Rachel Oberst, Georgianne M. Ciraolo, Charles V. Vorhees, Andrew P. Robinson, Stephen D. Miller, Jose A. Cancelas, Anat O. Stemmer-Rachamimov, Nancy Ratner Sep 2013

Nf1 Loss And Ras Hyperactivation In Oligodendrocytes Induce Nos-Driven Defects In Myelin And Vasculature, Debra A. Mayes, Tilat A. Rizvi, Haley E. Titus-Mitchell, Rachel Oberst, Georgianne M. Ciraolo, Charles V. Vorhees, Andrew P. Robinson, Stephen D. Miller, Jose A. Cancelas, Anat O. Stemmer-Rachamimov, Nancy Ratner

Neuroscience, Cell Biology & Physiology Faculty Publications

Patients with neurofibromatosis type 1 (NF1) and Costello syndrome Rasopathy have behavioral deficits. In NF1 patients, these may correlate with white matter enlargement and aberrant myelin. To model these features, we induced Nf1 loss or HRas hyperactivation in mouse oligodendrocytes. Enlarged brain white matter tracts correlated with myelin decompaction, downregulation of claudin-11, and mislocalization of connexin-32. Surprisingly, non-cell-autonomous defects in perivascular astrocytes and the blood-brain barrier (BBB) developed, implicating a soluble mediator. Nitric oxide (NO) can disrupt tight junctions and gap junctions, and NO and NO synthases (NOS1-NOS3) were upregulated in mutant white matter. Treating mice with the NOS inhibitor …


Antioxidant Rescue Of Nf1/Ras-Induced Myelin And Vasculature Dysfunction, Debra A. Mayes, Tilat A. Rizvi, Shyra J. Miller, Rachel Oberst, Anat Stemmer-Rachamimov, Nancy Ratner Jun 2012

Antioxidant Rescue Of Nf1/Ras-Induced Myelin And Vasculature Dysfunction, Debra A. Mayes, Tilat A. Rizvi, Shyra J. Miller, Rachel Oberst, Anat Stemmer-Rachamimov, Nancy Ratner

Neuroscience, Cell Biology & Physiology Faculty Publications

No abstract provided.


Effect Of Synthetic Aβ Peptide Oligomers And Fluorinated Solvents On Kv1.3 Channel Properties And Membrane Conductance, Maria I. Lioudyno, Matteo Broccio, Yuri Sokolov, Suhail Rasool, Jessica Wu, Michael T. Alkire, Virginia Liu, J. Ashot Kozak, Philip R. Dennison, Charles G. Glabe, Mathias Lösche, James E. Hall Apr 2012

Effect Of Synthetic Aβ Peptide Oligomers And Fluorinated Solvents On Kv1.3 Channel Properties And Membrane Conductance, Maria I. Lioudyno, Matteo Broccio, Yuri Sokolov, Suhail Rasool, Jessica Wu, Michael T. Alkire, Virginia Liu, J. Ashot Kozak, Philip R. Dennison, Charles G. Glabe, Mathias Lösche, James E. Hall

Neuroscience, Cell Biology & Physiology Faculty Publications

The impact of synthetic amyloid β (1–42) (Aβ1–42) oligomers on biophysical properties of voltage-gated potassium channels Kv 1.3 and lipid bilayer membranes (BLMs) was quantified for protocols using hexafluoroisopropanol (HFIP) or sodium hydroxide (NaOH) as solvents prior to initiating the oligomer formation. Regardless of the solvent used Aβ1–42 samples contained oligomers that reacted with the conformation-specific antibodies A11 and OC and had similar size distributions as determined by dynamic light scattering. Patch-clamp recordings of the potassium currents showed that synthetic Aβ1–42 oligomers accelerate the activation and inactivation kinetics of Kv 1.3 current with no significant effect …


Loss Of Renal Allografts Secondary To Candida Vascular Complications In Two Recipients From The Same Donor, Govardhana R. Yannam, Lucile E. Wrenshall, R. Brian Stevens Jan 2012

Loss Of Renal Allografts Secondary To Candida Vascular Complications In Two Recipients From The Same Donor, Govardhana R. Yannam, Lucile E. Wrenshall, R. Brian Stevens

Neuroscience, Cell Biology & Physiology Faculty Publications

Infections remain a major cause of morbidity and mortality in transplant patients. Organ recipients are also susceptible to donor-derived pathogens and the majority of donor infections are easily treatable. Rarely, some pathogens have produced life-threatening complications by compromising the vascular anastomosis. In this case series we report loss of two kidney allografts secondary to vascular complications due to Candida albicans. Both recipients received grafts from a common donor, in whom Candida bacteremia in the donor was not apparent at the time of organ acceptance but became apparent on delayed cultures.


Electronic Nose Based On Independent Component Analysis Combined With Partial Least Squares And Artificial Neural Networks For Wine Prediction, Teodoro Aguilera, Jesús Lozano, José A. Paredes, Francisco J. Alvarez, José I. Suárez Jan 2012

Electronic Nose Based On Independent Component Analysis Combined With Partial Least Squares And Artificial Neural Networks For Wine Prediction, Teodoro Aguilera, Jesús Lozano, José A. Paredes, Francisco J. Alvarez, José I. Suárez

Neuroscience, Cell Biology & Physiology Faculty Publications

The aim of this work is to propose an alternative way for wine classification and prediction based on an electronic nose (e-nose) combined with Independent Component Analysis (ICA) as a dimensionality reduction technique, Partial Least Squares (PLS) to predict sensorial descriptors and Artificial Neural Networks (ANNs) for classification purpose. A total of 26 wines from different regions, varieties and elaboration processes have been analyzed with an e-nose and tasted by a sensory panel. Successful results have been obtained in most cases for prediction and classification.


Electrophysiological Abnormalities In Sod1 Transgenic Models In Amyotrophic Lateral Sclerosis: The Commonalities And Differences, Sherif M. Elbasiouny, Katharina Quinlan, Tahra L. Eissa, Charles J. Heckman Jan 2012

Electrophysiological Abnormalities In Sod1 Transgenic Models In Amyotrophic Lateral Sclerosis: The Commonalities And Differences, Sherif M. Elbasiouny, Katharina Quinlan, Tahra L. Eissa, Charles J. Heckman

Neuroscience, Cell Biology & Physiology Faculty Publications

Since its first description in 1874 by Charcot, the hallmark feature of ALS is the progressive degeneration of upper and lower motoneurons (Charcot, 1874). In the spinal cord, motoneuron degeneration starts long before symptom onset and advances in a size-related fashion, in which large-size alpha-motoneurons degenerate first followed by small-size alpha-motoneurons (Pun et al., 2006; Hegedus et al., 2007; Hegedus et al., 2008). There are conflicting reports regarding the survival of the smallest-sized spinal motoneurons, the gamma-motoneurons (Swash and Fox, 1974; Sobue et al., 1981). Despite its original description, the neuronal degeneration in ALS is not limited to motoneurons. Recent …


The Effect Of Training On Motoneuron Survival In Amyotrophic Lateral Sclerosis: Which Motoneuron Type Is Saved?, Sherif M. Elbasiouny, Jenna E. Schuster Apr 2011

The Effect Of Training On Motoneuron Survival In Amyotrophic Lateral Sclerosis: Which Motoneuron Type Is Saved?, Sherif M. Elbasiouny, Jenna E. Schuster

Neuroscience, Cell Biology & Physiology Faculty Publications

Amyotrophic lateral sclerosis (ALS) is characterized by selective and progressive degeneration of motoneurons (MNs). Although the etiology of the disease is unknown, glutamate toxicity and reactive oxygen species toxicity have been strongly implicated in ALS pathophysiology, Training exercise has been proposed to provide a beneficial therapy during the early or late stages of ALS; however, some studies showed deleterious effects of exercise on survival in ALS.


Activation Of The Basolateral Membrane Cl- Conductance Essential For Electrogenic K+ Secretion Suppresses Electrogenic Cl- Secretion, Quanhua He, Susan T. Halm, Jin Zhang, Dan R. Halm Mar 2011

Activation Of The Basolateral Membrane Cl- Conductance Essential For Electrogenic K+ Secretion Suppresses Electrogenic Cl- Secretion, Quanhua He, Susan T. Halm, Jin Zhang, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

Adrenaline activates transient Cl--secretion and sustained K+-secretion across isolated distal colonic mucosa of guinea pig. The Ca++-activated Cl- channel inhibitor CaCCinh-A01 [30μM] significantly reduced electrogenic K+-secretion, detected as short-circuit current (Isc). This inhibition supported the cell model for K+-secretion in which basolateral membrane Cl- channels provide an exit pathway for Cl- entering the cell via Na+/K+/2Cl--cotransporters. CaCCinh-A01 inhibited both Isc and transepithelial conductance in a concentration dependent manner, IC50 = 6.3 μM. GlyH-101, another Cl- channel …


How Loss Of Neurofibromin In Oligodendrocytes Affects The Brain, Debra A. Mayes, Tilat A. Rizvi, Nathan T. Kolasinski, S. Miller, Nancy Ratner Jan 2011

How Loss Of Neurofibromin In Oligodendrocytes Affects The Brain, Debra A. Mayes, Tilat A. Rizvi, Nathan T. Kolasinski, S. Miller, Nancy Ratner

Neuroscience, Cell Biology & Physiology Faculty Publications

Neurofibromatosis type 1 patients are predisposed to central nervous system (CNS) phenotypes including enlarged brains, delayed acquisition of motor skills, brain tumors, and cognitive deficits. Imaging and pathologic analysis suggest that changes in white matter myelination may underlie both the enlargement of white matter tracts that contributes to megancephaly, and/or hyper-intense signals visualized on MRI. To study the role(s) of Nf1 and HRasin oligodendrocytes, we examined the optic nerve and corpus callosum,myelinated fiber tracts.We studiedNf1heterozygous mice,tamoxifen-induced Nf1 loss in mature oligodendrocytes (Plp-CreERT), and a new transgenic model in which the CNPase promoter drives expression of HRasG12V. Activated HRas and loss …


Perinatal Or Adult Nf1 Inactivation Using Tamoxifen-Inducible Plpcre Each Cause Neurofibroma Formation, Debra A. Mayes, Tilat A. Rizvi, Jose A. Cancelas, Nathan T. Kolasinski, Georgianne M. Ciraolo, Anat O. Stemmer-Rachamimov, Nancy Ratner Jan 2011

Perinatal Or Adult Nf1 Inactivation Using Tamoxifen-Inducible Plpcre Each Cause Neurofibroma Formation, Debra A. Mayes, Tilat A. Rizvi, Jose A. Cancelas, Nathan T. Kolasinski, Georgianne M. Ciraolo, Anat O. Stemmer-Rachamimov, Nancy Ratner

Neuroscience, Cell Biology & Physiology Faculty Publications

OBJECTIVES

Neurofibromas are tumors initiated by biallelic mutation of the NF1 tumor suppressor gene in the Schwann cell lineage. One idea within the field suggests that Nf1loss must occur within progenitor cells present within a critical window during Schwann cell development in order for neurofibromas to form. To test this hypothesis and to examine whethermyelinating Schwann cells can serve as aneurofibroma cell of origin, Nf1 loss was induced at perinatal or adult timepoints using a tamoxifen-inducible Plp-CreERT driver.

RESULTS

Perinatal loss of Nf1 resulted in small neurofibromas late in life, while adult loss caused large neurofibromas and morbidity beginning …


Toward A Mechanistic Understanding Of Narcolepsy With Cataplexy, William Mccurdy Jan 2011

Toward A Mechanistic Understanding Of Narcolepsy With Cataplexy, William Mccurdy

McNair Poster Presentations

Narcolepsy (hypersomnolence) is a disorder that affects 1 in 2000 individuals in the United States and it is characterized by excessive daytime sleepiness (EDS) and catalepsy, which is a sudden loss of muscle tone. As of relatively recent years, there has been a general consensus amongst the scientific community concerning the etiology of narcolepsy as numerous studies suggest that it is caused by the deficiency of neurotransmitters called orexin-A and orexin-B (or hypocretin-1 and hypocretin-2). Research suggests that deficiencies of these proteins are related to a mutation on chromosome 6 in the human leukocyte antigen (HLA) complex which is a …


Genome-Wide Association Studies At The Interface Of Alzheimer’S Disease And Epidemiologically Related Disorders, Christopher Ryan Simmons Jan 2011

Genome-Wide Association Studies At The Interface Of Alzheimer’S Disease And Epidemiologically Related Disorders, Christopher Ryan Simmons

University of Kentucky Doctoral Dissertations

Genome-wide association studies (GWAS)s provide an unbiased means of exploring the landscape of complex genetic disease. As such, these studies have identified genetic variants that are robustly associated with a multitude of conditions. I hypothesize that these genetic variants serve as excellent tools for evaluation of the genetic interface between epidemiologically related conditions. Herein, I test the association between SNPs associated with either (i) plasma lipids, (ii) rheumatoid arthritis (RA) or (iii) diabetes mellitus (DM) and late-onset Alzheimer’s disease (AD) to identify shared genetic variants. Regarding the most significantly AD-associated variants, I have also attempted to elucidate their molecular function. …


Q-Ve-Oph, A Negative Control For O-Phenoxy-Conjugated Caspase Inhibitors, Benjamin Southerland, Kashmira Kulkarni-Datar, Chanel Keoni, Rebecca Bricker, William C. Grunwald Jr., Daniel M. Ketcha, Eugene Hern, David R. Cool, Thomas L. Brown Jun 2010

Q-Ve-Oph, A Negative Control For O-Phenoxy-Conjugated Caspase Inhibitors, Benjamin Southerland, Kashmira Kulkarni-Datar, Chanel Keoni, Rebecca Bricker, William C. Grunwald Jr., Daniel M. Ketcha, Eugene Hern, David R. Cool, Thomas L. Brown

Neuroscience, Cell Biology & Physiology Faculty Publications

The broad-spectrum apoptosis (caspase) inhibitor, Q-VD-OPh, has been shown to have no side effects and is effective at a much lower concentration than other FMK-type caspase inhibitors. However, an appropriate negative control to use with this inhibi- tor has not been available. In this study, we developed and analyzed a new compound, based on the Q-VD-OPh backbone, which acts as a cognate negative control. To create the negative control, we substituted a glutamate residue for the aspartate residue to create Q-VE-OPh, thereby retaining the identical charge and molecular properties with only the addition of an extra –CH2 group. The purity …


Bitc Sensitizes Pancreatic Adenocarcinomas To Trail-Induced Apoptosis, Christina A. Wicker, Ravi P. Sahu, Kashmira Kulkarni-Datar, Sanjay K. Srivastava, Thomas L. Brown Jan 2010

Bitc Sensitizes Pancreatic Adenocarcinomas To Trail-Induced Apoptosis, Christina A. Wicker, Ravi P. Sahu, Kashmira Kulkarni-Datar, Sanjay K. Srivastava, Thomas L. Brown

Neuroscience, Cell Biology & Physiology Faculty Publications

Pancreatic adenocarcinoma is an aggressive cancer with a greater than 95% mortality rate and short survival after diagnosis. Chemotherapeutic resistance hinders successful treatment. This resistance is often associated with mutations in codon 12 of the K-Ras gene (K-Ras 12), which is present in over 90% of all pancreatic adenocarcinomas. Codon 12 mutations maintain Ras in a constitutively active state leading to continuous cellular proliferation. Our study determined if TRAIL resistance in pancreatic adenocarcinomas with K-Ras 12 mutations could be overcome by first sensitizing the cells with Benzyl isothiocyanate (BITC). BITC is a component of cruciferous vegetables and a cell cycle …


Local Synaptic Network Interactions In The Dentate Gyrus Of A Cortical Contusion Model Of Posttraumatic Epilepsy, Robert F. Hunt Iii Jan 2010

Local Synaptic Network Interactions In The Dentate Gyrus Of A Cortical Contusion Model Of Posttraumatic Epilepsy, Robert F. Hunt Iii

University of Kentucky Doctoral Dissertations

Posttraumatic epilepsy is a common consequence of brain trauma. However, little is known about how long-term changes in local excitatory and inhibitory synaptic networks contribute to epilepsy after closed-head brain injury. This study adapted a widely used model of experimental brain injury as a mouse model of posttraumatic epilepsy. Behavioral seizure activity and alterations in synaptic circuitry in the dentate gyrus were examined in mice after experimental cortical contusion brain injury. Spontaneous behavioral seizures were observed in 20% of mice after moderate injury and 36-40% of mice weeks after severe injury. In the dentate gyrus, most mice displayed regionally localized …


Neural Mechanisms Of Sympathetic Activation During Hyperinsulinemia And Obesity-Induced Hypertension, Megan Elyse Bardgett Jan 2010

Neural Mechanisms Of Sympathetic Activation During Hyperinsulinemia And Obesity-Induced Hypertension, Megan Elyse Bardgett

University of Kentucky Doctoral Dissertations

Obesity afflicts more than 30% of the U.S. population and is a major risk factor for the development of hypertension, type II diabetes, and cardiovascular disease. Studies in humans and animals indicate that obesity is associated with increased sympathetic outflow to the vasculature and kidneys. One mechanism postulated to underlie the increase in sympathetic nerve activity (SNA) in obesity is hyperinsulinemia. Little is known regarding the central circuitry underlying elevated SNA and arterial blood pressure (ABP) during hyperinsulinemia and obesity or if sympathoexcitatory circuits are still responsive to insulin in obesity.

Hyperinsulinemic-euglycemic clamps elevate SNA to the hind limb vasculature …


Gamma Motor Neurons Express Distinct Genetic Markers At Birth And Require Muscle Spindle-Derived Gdnf For Postnatal Survival, Neil A. Shneider, Meghan N. Brown, Courtney A. Smith, James Pickel, Francisco J. Alvarez Dec 2009

Gamma Motor Neurons Express Distinct Genetic Markers At Birth And Require Muscle Spindle-Derived Gdnf For Postnatal Survival, Neil A. Shneider, Meghan N. Brown, Courtney A. Smith, James Pickel, Francisco J. Alvarez

Neuroscience, Cell Biology & Physiology Faculty Publications

Background: Gamma motor neurons (γ-MNs) selectively innervate muscle spindle intrafusal fibers and regulate their sensitivity to stretch. They constitute a distinct subpopulation that differs in morphology, physiology and connectivity from α-MNs, which innervate extrafusal muscle fibers and exert force. The mechanisms that control the differentiation of functionally distinct fusimotor neurons are unknown. Progress on this question has been limited by the absence of molecular markers to specifically distinguish and manipulate γ-MNs. Recently, it was reported that early embryonic γ-MN precursors are dependent on GDNF. Using this knowledge we characterized genetic strategies to label developing γ-MNs based on GDNF receptor expression, …


Neuroendocrine Peptides Neuropeptide-Y (Npy) And Peptide-Yy (Pyy) Suppress Cl- Secretion And K+ Secretion In Guinea Pig Distal Colon Through Action At Y2-Receptors, Susan T. Halm, Jin Zhang, Dan R. Halm Nov 2008

Neuroendocrine Peptides Neuropeptide-Y (Npy) And Peptide-Yy (Pyy) Suppress Cl- Secretion And K+ Secretion In Guinea Pig Distal Colon Through Action At Y2-Receptors, Susan T. Halm, Jin Zhang, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

Electrogenic Cl and K+ secretion in isolated mucosa from guinea pig distal colon measured as short-circuit current (Isc) and transepithelial conductance (Gt) were stimulated by epinephrine (epi), prostaglandin-E2 (PGE2) and carbachol (CCh). neuropeptide-Y (NPY) and peptide-YY (PYY) inhibited by 60% Cl secretion activated by either PGE2 or PGE2+CCh with EC50’s of 16nM and 6nM, respectively. Neither peptide markedly inhibited the transient component of the PGE2+CCh response. Immunoreactivity (IR) for NPY was present in enteric ganglia and in proximity with crypts. Basolateral membranes of …


Viral Vectors In The Research Laboratory: Just How Safe Are They?, Dawn P. Wooley, Kimberly Kay Morris, Robert Mcrae, John C. Trefry Oct 2008

Viral Vectors In The Research Laboratory: Just How Safe Are They?, Dawn P. Wooley, Kimberly Kay Morris, Robert Mcrae, John C. Trefry

Neuroscience, Cell Biology & Physiology Faculty Publications

No abstract provided.


Investigating The Complexity Of Respiratory Patterns During The Laryngeal Chemoreflex, Andrei Dragomir, Yasemin Akay, Aidan K. Curran, Metin Akay Jun 2008

Investigating The Complexity Of Respiratory Patterns During The Laryngeal Chemoreflex, Andrei Dragomir, Yasemin Akay, Aidan K. Curran, Metin Akay

Dartmouth Scholarship

The laryngeal chemoreflex exists in infants as a primary sensory mechanism for defending the airway from the aspiration of liquids. Previous studies have hypothesized that prolonged apnea associated with this reflex may be life threatening and might be a cause of sudden infant death syndrome. In this study we quantified the output of the respiratory neural network, the diaphragm EMG signal, during the laryngeal chemoreflex and eupnea in early postnatal (3–10 days) piglets. We tested the hypothesis that diaphragm EMG activity corresponding to reflex-related events involved in clearance (restorative) mechanisms such as cough and swallow exhibit lower complexity, suggesting that …


Anti-Tumor Effect Of Doxycycline On Glioblastoma Cells, Andrea Wang-Gillam, Eric Siegel, Debra A. Mayes, Laura F. Hutchins, Yi-Hong Zhou Nov 2007

Anti-Tumor Effect Of Doxycycline On Glioblastoma Cells, Andrea Wang-Gillam, Eric Siegel, Debra A. Mayes, Laura F. Hutchins, Yi-Hong Zhou

Neuroscience, Cell Biology & Physiology Faculty Publications

AIM: Glioblastoma multiforme (GBM) is the most common primary brain tumor in humans, and it is highly invasive. Doxycycline, first identified as an antimicrobial agent, is a nonspecific inhibitor of matrix metalloproteinases (MMPs). Our objective was to investigate the anti-MMP effect of doxycycline at therapeutically acceptable levels on glioma cells in vitro.

METHODS: The MTT assay was used to determine the anti-proliferative effects of doxycycline. MMP2 activity and expression were determined by gelatinase zymography and real-time quantitative RT-PCR, respectively. Cell invasion was assessed by Matrigel invasion assay.

RESULTS: Doxycycline exerted mild anti-proliferative effects on all three glioma cell lines …