Open Access. Powered by Scholars. Published by Universities.®

Molecular and Cellular Neuroscience Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 15 of 15

Full-Text Articles in Molecular and Cellular Neuroscience

Modulation Of Gabaa Receptor By Neurosteroids And Protein Kinases In Health And Disease, Jaymin Jeong May 2021

Modulation Of Gabaa Receptor By Neurosteroids And Protein Kinases In Health And Disease, Jaymin Jeong

Electronic Thesis and Dissertation Repository

γ-aminobutyric acid type A receptors (GABAA receptors) underlie the majority of inhibitory synaptic transmission in the brain. Modulation of GABAergic activity occurs in development and normal physiological functioning of the brain, and changes to GABAergic function has been implicated in numerous neurological disorders including epilepsy. Neurosteroids, metabolites of steroid hormones, and kinases are known to modulate GABAA receptor mediated currents in health and disease. This thesis aims to investigate the effects of kinases and neurosteroids on modulating GABAA receptor-mediated currents in cortical pyramidal cells and their effects on the piriform cortex (PCtx) circuit in naïve rats and …


Kcnq2 Localization In The Brainstem, Christina Valera May 2020

Kcnq2 Localization In The Brainstem, Christina Valera

Honors Scholar Theses

KCNQ2 channels are potassium channels that serve to control neuronal excitability. Loss of function mutations in these channels are known to cause various forms of epilepsy. Recently, KCNQ2 R201C and R201H gain of function mutations have been shown to exhibit an exaggerated startle response and other unique phenotypes uncharacteristic of epilepsy. These phenotypes resemble hyperekplexia, a condition in which glycine neurotransmission in the spinal cord and brainstem is affected. While KCNQ2 has widespread localization throughout the brain, its presence in the brainstem remains unknown. We used immunostaining to determine the localization of KCNQ2 in the vagus nerve and hypoglossal nerve …


Polyglucosan Body Structure In Lafora Disease, M. Kathryn Brewer, Jean-Luc Putaux, Alberto Rondon, Annette M. Uittenbogaard, Mitchell A. Sullivan, Matthew S. Gentry Apr 2020

Polyglucosan Body Structure In Lafora Disease, M. Kathryn Brewer, Jean-Luc Putaux, Alberto Rondon, Annette M. Uittenbogaard, Mitchell A. Sullivan, Matthew S. Gentry

Lafora Epilepsy Cure Initiative Faculty Publications

Abnormal carbohydrate structures known as polyglucosan bodies (PGBs) are associated with neurodegenerative disorders, glycogen storage diseases (GSDs), and aging. A hallmark of the GSD Lafora disease (LD), a fatal childhood epilepsy caused by recessive mutations in the EPM2A or EPM2B genes, are cytoplasmic PGBs known as Lafora bodies (LBs). LBs result from aberrant glycogen metabolism and drive disease progression. They are abundant in brain, muscle and heart of LD patients and Epm2a-/- and Epm2b-/- mice. LBs and PGBs are histologically reminiscent of starch, semicrystalline carbohydrates synthesized for glucose storage in plants. In this study, we define LB architecture, …


Development Of An Intrahippocampal Kindling Model Of Epilepsy, Carter F. Jones Apr 2019

Development Of An Intrahippocampal Kindling Model Of Epilepsy, Carter F. Jones

Senior Theses and Projects

Epilepsy is a neurological condition that affects about 1% of the global population. This debilitating condition is associated with overexcitation and ineffective inhibition of neuronal pathways in the brain causing serious and a diverse set of symptoms, most prominently seizures. While some antiepileptic drug (AED) regimes have been proven to be effective in treating this condition, there are many cases where the drugs do not do enough. The ketogenic diet (KD) has been used for decades as an effective anticonvulsant. Its powerful and natural processes result in some patients becoming seizure-free. Sometimes, these patients remain free of seizures even after …


Biochemical Approaches For The Diagnosis And Treatment Of Lafora Disease, Mary Kathryn Brewer Jan 2019

Biochemical Approaches For The Diagnosis And Treatment Of Lafora Disease, Mary Kathryn Brewer

Theses and Dissertations--Molecular and Cellular Biochemistry

Glycogen is the sole carbohydrate storage molecule found in mammalian cells and plays an important role in cellular metabolism in nearly all tissues, including the brain. Defects in glycogen metabolism underlie the glycogen storage diseases (GSDs), genetic disorders with variable clinical phenotypes depending on the mutation type and affected gene(s). Lafora disease (LD) is a fatal form of progressive myoclonus epilepsy and a non-classical GSD. LD typically manifests in adolescence with tonic-clonic seizures, myoclonus, and a rapid, insidious progression. Patients experience increasingly severe and frequent epileptic episodes, loss of speech and muscular control, disinhibited dementia, and severe cognitive decline; death …


Drug-Resistant Epilepsy: Multiple Hypotheses, Few Answers, Fei Tang, Anika M. S. Hartz, Björn Bauer Jul 2017

Drug-Resistant Epilepsy: Multiple Hypotheses, Few Answers, Fei Tang, Anika M. S. Hartz, Björn Bauer

Pharmaceutical Sciences Faculty Publications

Epilepsy is a common neurological disorder that affects over 70 million people worldwide. Despite the recent introduction of new antiseizure drugs (ASDs), about one-third of patients with epilepsy have seizures refractory to pharmacotherapy. Early identification of patients who will become refractory to ASDs could help direct such patients to appropriate non-pharmacological treatment, but the complexity in the temporal patterns of epilepsy could make such identification difficult. The target hypothesis and transporter hypothesis are the most cited theories trying to explain refractory epilepsy, but neither theory alone fully explains the neurobiological basis of pharmacoresistance. This review summarizes evidence for and against …


Corticotropin Releasing Factor Receptor Type 1 Signaling In Epilepsy And Traumatic Brain Injury, V V Chakravarthi Narla Oct 2016

Corticotropin Releasing Factor Receptor Type 1 Signaling In Epilepsy And Traumatic Brain Injury, V V Chakravarthi Narla

Electronic Thesis and Dissertation Repository

Stress increases the frequency by which epileptic seizures occur. Corticotropin-releasing factor (CRF) coordinates neuroendocrine, autonomic and behavioral response to stress. This thesis sought to study the cellular and molecular mechanisms by which CRF regulates the activity of neural circuits in the piriform cortex (PC) in normal and epileptic states. The PC is richly innervated by CRF and 5-HT containing axons arising from the central amygdala and raphe nucleus. CRFR1 and 5-HT2A/CRs have been shown to interact in a manner where CRFR activation subsequently potentiates the activity of 5-HT2A/CRs. The first purpose of this thesis was …


Role Of Gluk1 Kainate Receptors In Seizures, Epileptic Discharges, And Epileptogenesis, Brita Fritsch, Janine Reis, Maciej Gasior, Rafal M. Kaminski, Michael A. Rogawski Apr 2014

Role Of Gluk1 Kainate Receptors In Seizures, Epileptic Discharges, And Epileptogenesis, Brita Fritsch, Janine Reis, Maciej Gasior, Rafal M. Kaminski, Michael A. Rogawski

Michael A. Rogawski

Kainate receptors containing the GluK1 subunit have an impact on excitatory and inhibitory neurotransmission in brain regions, such as the amygdala and hippocampus, which are relevant to seizures and epilepsy. Here we used 2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl) propanoic acid (ATPA), a potent and selective agonist of kainate receptors that include the GluK1 subunit, in conjunction with mice deficient in GluK1 and GluK2 kainate receptor subunits to assess the role of GluK1 kainate receptors in provoking seizures and in kindling epileptogenesis. We found that systemic ATPA, acting specifically via GluK1 kainate receptors, causes locomotor arrest and forelimb extension (a unique behavioral characteristic of GluK1 …


Role Of Gluk1 Kainate Receptors In Seizures, Epileptic Discharges, And Epileptogenesis, Brita Fritsch, Janine Reis, Maciej Gasior, Rafal M. Kaminski, Michael A. Rogawski Apr 2014

Role Of Gluk1 Kainate Receptors In Seizures, Epileptic Discharges, And Epileptogenesis, Brita Fritsch, Janine Reis, Maciej Gasior, Rafal M. Kaminski, Michael A. Rogawski

Michael A. Rogawski

Kainate receptors containing the GluK1 subunit have an impact on excitatory and inhibitory neurotransmission in brain regions, such as the amygdala and hippocampus, which are relevant to seizures and epilepsy. Here we used 2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl) propanoic acid (ATPA), a potent and selective agonist of kainate receptors that include the GluK1 subunit, in conjunction with mice deficient in GluK1 and GluK2 kainate receptor subunits to assess the role of GluK1 kainate receptors in provoking seizures and in kindling epileptogenesis. We found that systemic ATPA, acting specifically via GluK1 kainate receptors, causes locomotor arrest and forelimb extension (a unique behavioral characteristic of GluK1 …


A Catalog Of Scn1a Variants, Christoph Lossin Dec 2008

A Catalog Of Scn1a Variants, Christoph Lossin

Christoph Lossin, Ph.D.

Over the past 10 years mutations in voltage-gated sodium channels (Navs) have become closely associated with inheritable forms of epilepsy. One isoform in particular, Nav1.1 (gene symbol SCN1A), appears to be a superculprit, registering with more than 330 mutations to date. The associated phenotypes range from benign febrile seizures to extremely serious conditions, such as Dravet’s syndrome (SMEI). Despite the wealth of information, mutational analyses are cumbersome, owing to inconsistencies among the Nav1.1 sequences to which different research groups refer. Splicing variability is the core problem: Nav1.1 co-exists in three isoforms, two of them lack 11 or 28 amino acids …


Glutamate Excitotoxicity In Epilepsy And Ischemia, Mangala Meenakshi Soundarapandian Jan 2007

Glutamate Excitotoxicity In Epilepsy And Ischemia, Mangala Meenakshi Soundarapandian

Electronic Theses and Dissertations

'Excitotoxicity' represents the excitatory amino acid mediated degeneration of neurons. Glutamate is the major excitatory neurotransmitter in the brain. Glutamate excitotoxicity has been implicated in a number of neurodegenerative disorders like Stroke, Epilepsy, Alzheimer's disease and traumatic brain injury. This neurotoxicity is summed up by the 'glutamate hypothesis' which describes the cause of neuronal cell death as an excessive release of glutamate causing over excitation of the glutamate receptors and subsequent increase in influx of calcium leading to cell death. An effort to counteract this neurotoxicity has lead to the development of glutamate receptor antagonists that can effectively serve as …


Single-Channel Properties Of Human Nav1.1 And Mechanism Of Channel Dysfunction In Scn1a-Associated Epilepsy, C. Vanoye, Christoph Lossin, T. H. Rhodes, Alfred L. George Dec 2004

Single-Channel Properties Of Human Nav1.1 And Mechanism Of Channel Dysfunction In Scn1a-Associated Epilepsy, C. Vanoye, Christoph Lossin, T. H. Rhodes, Alfred L. George

Christoph Lossin, Ph.D.

Mutations in genes encoding neuronal voltage-gated sodium channel subunits have been linked to inherited forms of epilepsy. The majority of mutations (>100) associated with generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy of infancy (SMEI) occur in SCN1A encoding the NaV1.1 neuronal sodium channel alpha-subunit. Previous studies demonstrated functional heterogeneity among mutant SCN1A channels, revealing a complex relationship between clinical and biophysical phenotypes. To further understand the mechanisms responsible for mutant SCN1A behavior, we performed a comprehensive analysis of the single-channel properties of heterologously expressed recombinant WT-SCN1A channels. Based on these data, we then determined the …


Non-Inactivating Voltage-Gated Sodium Channels In Severe Myoclonic Epilepsy Of Infancy, T. H. Rhodes, Christoph Lossin, C. Vanoye, Alfred L. George Jan 2004

Non-Inactivating Voltage-Gated Sodium Channels In Severe Myoclonic Epilepsy Of Infancy, T. H. Rhodes, Christoph Lossin, C. Vanoye, Alfred L. George

Christoph Lossin, Ph.D.

Mutations in SCN1A, the gene encoding the brain voltage-gated sodium channel alpha(1) subunit (Na(V)1.1), are associated with at least two forms of epilepsy, generalized epilepsy with febrile seizures plus and severe myoclonic epilepsy of infancy (SMEI). We examined the functional properties of five SMEI mutations by using whole-cell patch-clamp analysis of heterologously expressed recombinant human SCN1A. Two mutations (F902C and G1674R) rendered SCN1A channels nonfunctional, and a third allele (G1749E) exhibited minimal functional alterations. However, two mutations within or near the S4 segment of the fourth repeat domain (R1648C and F1661S) conferred significant impairments in fast inactivation, including persistent, noninactivating …


Epilepsy-Associated Dysfunction In The Voltage-Gated Neuronal Sodium Channel Scn1a, Christoph Lossin, T. Rhodes, R. Desai, C. Vanoye, S. Caniciu, O. Devinsky, A. George Dec 2003

Epilepsy-Associated Dysfunction In The Voltage-Gated Neuronal Sodium Channel Scn1a, Christoph Lossin, T. Rhodes, R. Desai, C. Vanoye, S. Caniciu, O. Devinsky, A. George

Christoph Lossin, Ph.D.

Mutations in SCN1A, the gene encoding the brain voltage-gated sodium channel subunit (Nav1.1) are associated with at least two forms of epilepsy, generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy of infancy (SMEI). We examined the functional properties of four GEFS+ alleles and one SMEI allele using whole-cell patch-clamp analysis of heterologously expressed recombinant human SCN1A. One previously reported GEFS+ mutation (I1656M) and an additional novel allele (R1657C), both affecting residues in a voltage-sensing S4 segment, exhibited a similar depolarizing shift in the voltage dependence of activation. Additionally, R1657C showed a 50% reduction in current density and …


Molecular Basis Of An Inherited Epilepsy, Christoph Lossin, T. H. Rhodes, C. Vanoye, D. Wang, Alfred L. George Dec 2001

Molecular Basis Of An Inherited Epilepsy, Christoph Lossin, T. H. Rhodes, C. Vanoye, D. Wang, Alfred L. George

Christoph Lossin, Ph.D.

Mutations in SCN1A, the gene encoding the brain voltage-gated sodium channel alpha1 subunit (NaV1.1), are associated with at least two forms of epilepsy, generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy of infancy (SMEI). We examined the functional properties of four GEFS+ alleles and one SMEI allele using whole-cell patch-clamp analysis of heterologously expressed recombinant human SCN1A. One previously reported GEFS+ mutation (I1656M) and an additional novel allele (R1657C), both affecting residues in a voltage-sensing S4 segment, exhibited a similar depolarizing shift in the voltage dependence of activation. Additionally, R1657C showed a 50% reduction in current density …