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Articles 1 - 19 of 19
Full-Text Articles in Neuroscience and Neurobiology
Role Of Gluk1 Kainate Receptors In Seizures, Epileptic Discharges, And Epileptogenesis, Brita Fritsch, Janine Reis, Maciej Gasior, Rafal M. Kaminski, Michael A. Rogawski
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
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 …
Preclinical Pharmacology Of Perampanel, A Selective Non-Competitive Ampa Receptor Antagonist, Michael A. Rogawski, Takahisa Hanada
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
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
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
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 …
Embryonic Stem Cell Therapy For Intractable Epilepsy., Janice Naegele
Embryonic Stem Cell Therapy For Intractable Epilepsy., Janice Naegele
Janice R Naegele
Envisioning a world in which humans are able to regenerate severed limbs, rewire neural pathways, and enhance sensory perception has been a mainstay of science fiction novels and movies for decades. While human limb regeneration is still not possible, remarkable developments in the fields of stem cell biology and neuroscience are leading the way for stem cell-based therapies to amend brain and spinal cord damage and repair sensory organs. In this chapter, we discuss recent efforts to derive neural stem cells from embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) and their applications to treating conditions such as …
Neurosteroids—Endogenous Regulators Of Seizure Susceptibility And Role In The Treatment Of Epilepsy, Doodipala S. Reddy, Michael A. Rogawski
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 …
Nontraditional Epilepsy Treatment Approaches, Michael A. Rogawski, Gregory L. Holmes
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.
A Catalog Of Scn1a Variants, Christoph Lossin
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 …
Common Pathophysiologic Mechanisms In Migraine And Epilepsy, Michael A. Rogawski
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
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
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 …
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
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 …
Neurosteroids: Endogenous Modulators Of Seizure Susceptibility, Michael A. Rogawski, Doodipala S. Reddy
Neurosteroids: Endogenous Modulators Of Seizure Susceptibility, Michael A. Rogawski, Doodipala S. Reddy
Michael A. Rogawski
No abstract provided.
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
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
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 …
Epilepsy (Ionotropic Glutamate Receptors As Therapeutic Targets), Wolfgang Löscher, Michael A. Rogawski
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
Excitatory Amino Acids And Seizures, Michael A. Rogawski
Michael A. Rogawski
No abstract provided.