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Accelerated Forgetting In People With Epilepsy: Pathologic Memory Loss, Its Neural Basis, And Potential Therapies, Sarah Ashley Steimel Phd Jan 2023

Accelerated Forgetting In People With Epilepsy: Pathologic Memory Loss, Its Neural Basis, And Potential Therapies, Sarah Ashley Steimel Phd

Dartmouth College Ph.D Dissertations

While forgetting is vital to human functioning, delineating between normative and disordered forgetting can become incredibly complex. This thesis characterizes a pathologic form of forgetting in epilepsy, identifies a neural basis, and investigates the potential of stimulation as a therapeutic tool. Chapter 2 presents a behavioral characterization of the time course of Accelerated Long-Term Forgetting (ALF) in people with epilepsy (PWE). This chapter shows evidence of ALF on a shorter time scale than previous studies, with a differential impact on recall and recognition. Chapter 3 builds upon the work in Chapter 2 by extending ALF time points and investigating the …


Characterizing The Roles Of Cannabinoid Receptor 1 & 2 In Zebrafish Behavior, Metabolism, And Seizure-Induced Activity, Kayci Kimmons May 2022

Characterizing The Roles Of Cannabinoid Receptor 1 & 2 In Zebrafish Behavior, Metabolism, And Seizure-Induced Activity, Kayci Kimmons

Honors Theses

Epileptic disorders like Dravet Syndrome require novel studies to determine the most ideal treatment. New research linking the endocannabinoid system (ECS) to epileptic disorders is arising, but there is still much to be discovered about the function and regulatory impact of the endocannabinoid system and its receptors in epilepsies like Dravet. In this study, knockout models of larval and adult zebrafish (Danio rerio) were used to investigate the roles of cannabinoid receptors 1 & 2 in behavior, brain mitochondrial metabolism, and seizure-induced activity following exposure to THC and CBD. Larval zebrafish which lacked cannabinoid receptor 1 exhibited increased …


Axon Initial Segment Morphology Across Typical Cortical Development And In Mouse Models Of Neurodevelopmental Disorders With A High Incidence Of Epilepsy, Rachel Ali Rodriguez Dec 2021

Axon Initial Segment Morphology Across Typical Cortical Development And In Mouse Models Of Neurodevelopmental Disorders With A High Incidence Of Epilepsy, Rachel Ali Rodriguez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neurodevelopmental disorders (NDDs) are commonly associated with a high incidence of epileptic seizures which result from excessive firing of neurons. The axon initial segment (AIS) is a neuronal compartment essential for the control of activity patterns of neurons. The AIS undergoes important modifications during development, but the molecular mechanisms that affect the development, morphology, and protein composition of the AIS are still not well understood. We examined AIS morphology of medial prefrontal cortex (mPFC) pyramidal neurons in wildtype mice across development and in two mouse models of NDDs. Results indicate restructurings at the AIS during typical development, some of which …


Targeting Pathogenic Lafora Bodies In Lafora Disease Using An Antibody-Enzyme Fusion, M. Kathryn Brewer, Annette M. Uittenbogaard, Grant L. Austin, Dyann M. Segvich, Anna Depaoli-Roach, Peter J. Roach, John J. Mccarthy, Zoe R. Simmons, Jason A. Brandon, Zhengqiu Zhou, Jill Zeller, Lyndsay E. A. Young, Ramon C. Sun, James R. Pauly, Nadine M. Aziz, Bradley L. Hodges, Tracy R. Mcknight, Dustin D. Armstrong, Matthew S. Gentry Jul 2019

Targeting Pathogenic Lafora Bodies In Lafora Disease Using An Antibody-Enzyme Fusion, M. Kathryn Brewer, Annette M. Uittenbogaard, Grant L. Austin, Dyann M. Segvich, Anna Depaoli-Roach, Peter J. Roach, John J. Mccarthy, Zoe R. Simmons, Jason A. Brandon, Zhengqiu Zhou, Jill Zeller, Lyndsay E. A. Young, Ramon C. Sun, James R. Pauly, Nadine M. Aziz, Bradley L. Hodges, Tracy R. Mcknight, Dustin D. Armstrong, Matthew S. Gentry

Molecular and Cellular Biochemistry Faculty Publications

Lafora disease (LD) is a fatal childhood epilepsy caused by recessive mutations in either the EPM2A or EPM2B gene. A hallmark of LD is the intracellular accumulation of insoluble polysaccharide deposits known as Lafora bodies (LBs) in the brain and other tissues. In LD mouse models, genetic reduction of glycogen synthesis eliminates LB formation and rescues the neurological phenotype. Therefore, LBs have become a therapeutic target for ameliorating LD. Herein, we demonstrate that human pancreatic α-amylase degrades LBs. We fused this amylase to a cell-penetrating antibody fragment, and this antibody-enzyme fusion (VAL-0417) degrades LBs in vitro and dramatically reduces LB …


Mitochondrial Metabolism In Major Neurological Diseases, Zhengqiu Zhou, Grant L. Austin, Lyndsay E. A. Young, Lance A. Johnson, Ramon Sun Nov 2018

Mitochondrial Metabolism In Major Neurological Diseases, Zhengqiu Zhou, Grant L. Austin, Lyndsay E. A. Young, Lance A. Johnson, Ramon Sun

Molecular and Cellular Biochemistry Faculty Publications

Mitochondria are bilayer sub-cellular organelles that are an integral part of normal cellular physiology. They are responsible for producing the majority of a cell’s ATP, thus supplying energy for a variety of key cellular processes, especially in the brain. Although energy production is a key aspect of mitochondrial metabolism, its role extends far beyond energy production to cell signaling and epigenetic regulation–functions that contribute to cellular proliferation, differentiation, apoptosis, migration, and autophagy. Recent research on neurological disorders suggest a major metabolic component in disease pathophysiology, and mitochondria have been shown to be in the center of metabolic dysregulation and possibly …


Identifying Kif Subtype That Mediates Axonal Targeting Of Kv7 Channels, Allison Houghton, Jennifer Walters, Mary Hong, Dhruv Joshi, Hee Jung Chung Jul 2018

Identifying Kif Subtype That Mediates Axonal Targeting Of Kv7 Channels, Allison Houghton, Jennifer Walters, Mary Hong, Dhruv Joshi, Hee Jung Chung

PRECS 2018

Early-onset Benign Familial Neonatal Epilepsy (BFNE) and Epileptic Encephalopathy (EE), are associated with mutations in neuronal KCNQ/Kv7 channel subunits Kv7.2 and Kv7.3. Kv7 channels are voltage-dependent potassium channels. Enriched at the axonal plasma membrane, they pump potassium ions out of the neurons and inhibit repetitive or burst firing of action potentials. A single neuronal Kv7 channel is a heterotetramer composed of two Kv7.2 and two Kv7.3 subunits. BFNE and EE mutations in Kv7.2 and Kv7.3 lead to decreased surface expression along the axon, which means less potassium ions are moved across the axonal membrane where action potentials are generated and …


Functional Neuroplasticity In The Nucleus Tractus Solitarius And Increased Risk Of Sudden Death In Mice With Acquired Temporal Lobe Epilepsy, Isabel D. Derera, Brian P. Delisle, Bret N. Smith Oct 2017

Functional Neuroplasticity In The Nucleus Tractus Solitarius And Increased Risk Of Sudden Death In Mice With Acquired Temporal Lobe Epilepsy, Isabel D. Derera, Brian P. Delisle, Bret N. Smith

Physiology Faculty Publications

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in individuals with refractory acquired epilepsy. Cardiorespiratory failure is the most likely cause in most cases, and central autonomic dysfunction has been implicated as a contributing factor to SUDEP. Neurons of the nucleus tractus solitarius (NTS) in the brainstem vagal complex receive and integrate vagally mediated information regarding cardiorespiratory and other autonomic functions, and GABAergic inhibitory NTS neurons play an essential role in modulating autonomic output. We assessed the activity of GABAergic NTS neurons as a function of epilepsy development in the pilocarpine-induced status epilepticus (SE) model of …


Linking Molecular, Electrical And Anatomical Properties Of Human Epileptic Brain, Shruti Bagla Jan 2014

Linking Molecular, Electrical And Anatomical Properties Of Human Epileptic Brain, Shruti Bagla

Wayne State University Dissertations

Epilepsy is a common neurological disorder of recurrent unprovoked seizures. It affects almost 1% of the world population. Although there is a wide range of anti-epileptic drugs (AEDs) available, they only treat the seizure symptoms and do not cure the disease itself. The poor role of AEDs can be attributed to the lack of knowledge of exact mechanisms and networks that produce epileptic activities in the neocortex. At present, the best cure for epilepsy is surgical removal of electrically localized epileptic brain tissue. Surgically removed brain tissue presents an excellent opportunity to discover the molecular and cellular basis of human …


Preclinical Pharmacology Of Perampanel, A Selective Non-Competitive Ampa Receptor Antagonist, Michael A. Rogawski, Takahisa Hanada Dec 2012

Preclinical Pharmacology Of Perampanel, A Selective Non-Competitive Ampa Receptor Antagonist, Michael A. Rogawski, Takahisa Hanada

Michael A. Rogawski

Perampanel [2-(2-oxo-1-phenyl-5-pyridin-2-yl-1,2-dihydropyridin-3-yl) benzonitrile; E2007] is a potent, selective, orally active non-competitive AMPA receptor antagonist developed for the treatment of epilepsy. Perampanel has a 2,3′-bipyridin-6′-one core structure, distinguishing it chemically from other AMPA receptor antagonist classes. Studies in various physiological systems indicate that perampanel selectively inhibits AMPA receptor-mediated synaptic excitation without affecting NMDA receptor responses. Blocking of AMPA receptors occurs at an allosteric site that is distinct from the glutamate recognition site. Radioligand-binding studies suggest that the blocking site coincides with that of the non-competitive antagonist GYKI 52466, believed to be on linker peptide segments of AMPA receptor subunits that transduce …


Glia And Epilepsy: Excitability And Inflammation, Orrin Devinsky, Annamaria Vezzani, Souhel Najjar, Nihal C. De Lanerolle, Michael A. Rogawski Dec 2012

Glia And Epilepsy: Excitability And Inflammation, Orrin Devinsky, Annamaria Vezzani, Souhel Najjar, Nihal C. De Lanerolle, Michael A. Rogawski

Michael A. Rogawski

Epilepsy is characterized by recurrent spontaneous seizures due to hyperexcitability and hypersynchrony of brain neurons. Current theories of pathophysiology stress neuronal dysfunction and damage, and aberrant connections as relevant factors. Most antiepileptic drugs target neuronal mechanisms. However, nearly one-third of patients have seizures that are refractory to available medications; a deeper understanding of mechanisms may be required to conceive more effective therapies. Recent studies point to a significant contribution by nonneuronal cells, the glia – especially astrocytes and microglia – in the pathophysiology of epilepsy. This review critically evaluates the role of glia-induced hyperexcitability and inflammation in epilepsy.


Ampa Receptors As A Molecular Target In Epilepsy Therapy, Michael A. Rogawski Dec 2012

Ampa Receptors As A Molecular Target In Epilepsy Therapy, Michael A. Rogawski

Michael A. Rogawski

Epileptic seizures occur as a result of episodic abnormal synchronous discharges in cerebral neuronal networks. Although a variety of nonconventional mechanisms may play a role in epileptic synchronization, cascading excitation within networks of synaptically connected excitatory glutamatergic neurons is a classical mechanism. As is the case throughout the central nervous system, fast synaptic excitation within and between brain regions relevant to epilepsy is mediated predominantly by AMPA receptors. By inhibiting glutamate-mediated excitation, AMPA receptor antagonists markedly reduce or abolish epileptiform activity in in vitro preparations and confer seizure protection in a broad range of animal seizure models. NMDA receptors may …


How Theories Evolved Concerning The Mechanism Of Action Of Barbiturates, Wolfgang Löscher, Michael A. Rogawski Nov 2012

How Theories Evolved Concerning The Mechanism Of Action Of Barbiturates, Wolfgang Löscher, Michael A. Rogawski

Michael A. Rogawski

The barbiturate phenobarbital has been in use in the treatment of epilepsy for 100 years. It has long been recognized that barbiturates act by prolonging and potentiating the action of γ-aminobutyric acid (GABA) on GABA-A) receptors and at higher concentrations directly activating the receptors. A large body of data supports the concept that GABA-A) receptors are the primary central nervous system target for barbiturates, including the finding that transgenic mice with a point mutation in the β3 GABA-A)-receptor subunit exhibit diminished sensitivity to the sedative and immobilizing actions of the anesthetic barbiturate pentobarbital. Although phenobarbital is only modestly less potent …


Neurosteroids—Endogenous Regulators Of Seizure Susceptibility And Role In The Treatment Of Epilepsy, Doodipala S. Reddy, Michael A. Rogawski Dec 2011

Neurosteroids—Endogenous Regulators Of Seizure Susceptibility And Role In The Treatment Of Epilepsy, Doodipala S. Reddy, Michael A. Rogawski

Michael A. Rogawski

Certain steroid hormone metabolites that have activity as modulators of GABA-A receptors but lack conventional hormonal effects—including allopregnanolone and allotetrahydrodeoxycorticosterone—are synthesized within the brain, predominantly in principle (excitatory) neurons, and also in peripheral tissues. At low concentrations, such neurosteroids potentiate GABA-A receptor currents, whereas at higher concentrations they directly activate the receptor; large magnitude effects occur on nonsynaptic delta subunit-containing GABA-A receptors that mediate tonic currents. GABA-A receptor modulatory neurosteroids confer seizure protection in diverse animal models, without tolerance during chronic administration. Endogenous neurosteroids may play a role in catamenial epilepsy, stress-induced changes in seizure susceptibility, temporal lobe epilepsy, and …


The Interictal State In Epilepsy And Behavior, Daniel Tice Barkmeier Jan 2010

The Interictal State In Epilepsy And Behavior, Daniel Tice Barkmeier

Wayne State University Dissertations

Epilepsy is one of the most common neurological diseases, affecting up to 1% of the world population. Epilepsy remains poorly understood and there are currently no medications to cure it. Patients with epilepsy have both seizures as well as another type of abnormal activity between seizures, known as interictal spikes. Interictal spikes have thus far been poorly researched, yet growing evidence supports an important role for them in epilepsy. In this project, we first show the high variability between reviewers in marking interictal spikes on intracranial EEG, and then develop and test an automated detection method to solve this problem. …


A Model For Understanding Epilepsy In Peromyscus, Kevin Ryan, Gabor Szalai Jan 2010

A Model For Understanding Epilepsy In Peromyscus, Kevin Ryan, Gabor Szalai

Journal of the South Carolina Academy of Science

No abstract provided.


Neurosteroid Replacement Therapy For Catamenial Epilepsy, Doodipala S. Reddy, Michael A. Rogawski Apr 2009

Neurosteroid Replacement Therapy For Catamenial Epilepsy, Doodipala S. Reddy, Michael A. Rogawski

Michael A. Rogawski

Perimenstural catamenial epilepsy, the cyclical occurrence of seizure exacerbations near the time of menstruation, affects a high proportion of women of reproductive age with drug refractory epilepsy. Enhanced seizure susceptibility in perimenstrual catamenial epilepsy is believed to be due to the withdrawal of the progesterone-derived GABA-A receptor modulating neurosteroid allopregnanolone as a result of the fall in progesterone at the time of menstruation. Studies in a rat pseudopregnancy model of catamenial epilepsy indicate that following neurosteroid withdrawal there is enhanced susceptibility to chemoconvulsant seizures. There is also a transitory increase in the frequency of spontaneous seizures in epleptic rats that …


Nontraditional Epilepsy Treatment Approaches, Michael A. Rogawski, Gregory L. Holmes Mar 2009

Nontraditional Epilepsy Treatment Approaches, Michael A. Rogawski, Gregory L. Holmes

Michael A. Rogawski

Overview of articles published in a special issue of Neurotherapeutics (April 2009) on nontraditional (non-drug) epilepsy treatment approaches. From the Fourth Workshop on New Horizons in the Development of Antiepileptic Drugs: Nontraditional Approaches to Treat Epilepsy, which was held at the Clontarf Castle, Dublin, March 5-7, 2008.


Intrinsic Severity As A Determinant Of Antiepileptic Drug Refractoriness, Michael A. Rogawski, Michael R. Johnson Sep 2008

Intrinsic Severity As A Determinant Of Antiepileptic Drug Refractoriness, Michael A. Rogawski, Michael R. Johnson

Michael A. Rogawski

For the most part, resistance to medications in epilepsy is independent of the choice of antiepileptic drug. This simple clinical observation constrains the possible biological mechanisms for drug refractory epilepsy by imposing a requirement to explain resistance for a diverse set of chemical structures that act on an even more varied group of molecular targets. To date, research on antiepileptic drug refractoriness has been guided by the “drug transporter overexpression” and the “reduced drug-target sensitivity” hypotheses. These concepts posit that drug refractoriness is a condition separate from the underlying epilepsy. Inadequacies in both hypotheses mandate a fresh approach to the …


Common Pathophysiologic Mechanisms In Migraine And Epilepsy, Michael A. Rogawski Dec 2007

Common Pathophysiologic Mechanisms In Migraine And Epilepsy, Michael A. Rogawski

Michael A. Rogawski

Migraine and epilepsy are comorbid episodic disorders that have common pathophysiologic mechanisms. Migraine attacks, like epileptic seizures, may be triggered by excessive neocortical cellular excitability; in migraine, however, the hyperexcitability is believed to transition to cortical spreading depression rather than to the hypersynchronous activity that characterizes seizures. Some forms of epilepsy and migraine are known to be channelopathies. Mutations in the same genes can cause either migraine or epilepsy or, in some cases, both. Given the likely commonalities in the underlying cellular and molecular mechanisms, it is not surprising that some antiepileptic drugs, including valproate, topiramate, and gabapentin, are effective …


Epilepsy: Mechanisms Of Drug Action And Clinical Treatment, William Theodore, Michael Rogawski Dec 2006

Epilepsy: Mechanisms Of Drug Action And Clinical Treatment, William Theodore, Michael Rogawski

Michael A. Rogawski

No abstract provided.


Neuroprotective And Disease-Modifying Effects Of The Ketogenic Diet, Maciej Gasior, Michael A. Rogawski, Adam L. Hartman Aug 2006

Neuroprotective And Disease-Modifying Effects Of The Ketogenic Diet, Maciej Gasior, Michael A. Rogawski, Adam L. Hartman

Michael A. Rogawski

The ketogenic diet has been in clinical use for over 80 years, primarily for the symptomatic treatment of epilepsy. A recent clinical study has raised the possibility that exposure to the ketogenic diet may confer long-lasting therapeutic benefits for patients with epilepsy. Moreover, there is evidence from uncontrolled clinical trials and studies in animal models that the ketogenic diet can provide symptomatic and disease-modifying activity in a broad range of neurodegenerative disorders including Alzheimer’s disease and Parkinson’s disease, and may also be protective in traumatic brain injury and stroke. These observations are supported by studies in animal models and isolated …


Neurosteroids: Endogenous Modulators Of Seizure Susceptibility, Michael A. Rogawski, Doodipala S. Reddy Dec 2003

Neurosteroids: Endogenous Modulators Of Seizure Susceptibility, Michael A. Rogawski, Doodipala S. Reddy

Michael A. Rogawski

No abstract provided.


Epilepsy (Ionotropic Glutamate Receptors As Therapeutic Targets), Wolfgang Löscher, Michael A. Rogawski Dec 2001

Epilepsy (Ionotropic Glutamate Receptors As Therapeutic Targets), Wolfgang Löscher, Michael A. Rogawski

Michael A. Rogawski

No abstract provided.


Excitatory Amino Acids And Seizures, Michael A. Rogawski Dec 1994

Excitatory Amino Acids And Seizures, Michael A. Rogawski

Michael A. Rogawski

No abstract provided.