Epilepsies are a diverse collection of brain disorders that affect 1–2% of the population. Current therapies are unsatisfactory as they provide only symptomatic relief, are effective in only a subset of affected individuals, and are often accompanied by persistent toxic effects. It is hoped that insight into the cellular and molecular mechanisms of epileptogenesis will lead to new therapies, prevention, or even a cure. Emerging insights point to alterations of synaptic function and intrinsic properties of neurons as common mechanisms underlying the hyperexcitability in diverse forms of epilepsy.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
References
Adams, R. D., Victor, M. & Ropper, A. H. Principles of Neurology, 6th edn 1–317 (McGraw-Hill, New York, 1997).
Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 30, 389–399 (1989).
Berkovic, S. in Epilepsy: AComprehensive Textbook (eds Engel, J. & Pedley, T. A.) 217–224 (Lippincott- Raven, Philadelphia, 1997).
Puranam, R. S. & McNamara, J. O. Seizure disorders in mutant mice: relevance to human epilepsies. Curr. Opin. Neurobiol. (in the press).
Pennacchio, L. A. et al. Mutations in the gene encoding cystatin B in progressive myoclonus epilepsy (EPM1). Science 271, 1731–1734 (1996).
Fox, J. W. et al. Mutations in filamin 1 prevent migration of cerebral cortical neurons in human periventricular heterotopia. Neuron 21, 1315–1325 (1998).
Ptacek, L. J. Channelopathies: ion channel disorders of muscle as a paradigm for paroxysmal disorders of the nervous system. Neuromusc. Disord. 7, 250–255 (1997).
Wallace, R. H. et al. Febrile seizures and generalized epilepsy associated with a mutation in the Na+- channel β1 subunit gene SCN1B. Nature Genet. 19, 366–370 (1998).
Singh, R., Scheffer, I. E., Crossland, K. & Berkovic, S. F. Generalized epilepsy with febrile seizures plus: a common childhood-onset genetic epilepsy syndrome. Ann. Neurol. 45, 75–81 (1999).
Biervert, C. et al. Apotassiumchannelmutation in neonatal human epilepsy. Science 279, 403–406 (1998).
Singh, N. A. et al. A novel potassium channel gene, KCNQ2, is mutated in an inherited epilepsy of newborns. Nature Genet. 18, 25–29 (1998).
Charlier, C. et al. A pore mutation in a novel KQT-like potassium channel gene in an idiopathic epilepsy family. Nature Genet. 18, 53–55 (1998).
Leppert, M. et al. Benign familial neonatal convulsions linked to genetic markers on chromosome 20. Nature 337, 647–648 (1989).
Lewis, T. B., Leach, R. J., Ward, K., o'Connell, P. & Ryan, S. G. Genetic heterogeneity in benign familial neonatal convulsions: identification of a new locus on chromosome 8q. Am. J. Hum. Genet. 53, 670–675 (1993).
Wang, Q. et al. Positional cloning of a novel potassium channel gene: KVLQT1 mutations cause cardiac arrhythmias. Nature Genet. 12, 17–23 (1996).
Neyroud, N. et al. A novel mutation in the potassium channel gene KVLQT1 causes the Jervell and Lange-Nielsen cardioauditory syndrome. Nature Genet. 15, 186–189 (1997).
Schroeder, B. C., Kubisch, C., Stein, V. & Jentsch, T. J. Moderate loss of function of cyclic-AMPmodulated KCNQ2/KCNQ3 K+ channels causes epilepsy. Nature 396, 687–690 (1998).
Steinlein, O. K. et al. A missense mutation in the neuronal nicotinic acetylcholine receptor α4 subunit is associated with autosomal dominant nocturnal frontal lobe epilepsy. Nature Genet. 11, 201–204 (1995).
Phillips, H. A. et al. Localization of a gene for autosomal dominant nocturnal frontal lobe epilepsy to chromosome 20q13.2. Nature Genet. 10, 117–120 (1995).
Steinlein, O. K. et al. An insertion mutation of the CHRNA4 gene in a family with autosomal dominant nocturnal frontal lobe epilepsy. Hum. Mol. Genet. 6, 943–947 (1997).
Phillips, H. A. et al. Genetic heterogeneity and evidence for a second locus at 15q24. Am. J. Hum. Genet. 63, 1108–1116 (1998).
Weiland, S., Witzemann, V., Villarroel, A., Propping, P. & Steinlein, O. An amino acid exchange in the second transmembrane segment of a neuronal nicotinic receptor causes partial epilepsy by altering its desensitization kinetics. FEBS Lett. 398, 91–96 (1996).
Kuryatov, A., Gerzanich, V., Nelson, M., Olale, F. & Lindstrom, J. Mutation causing autosomal dominant frontal lobe epilepsy alters Ca2+ permeability, conductance and gating of human α4β2 nicotinic acetylcholine receptors. J. Neurosci. 17, 9035–9047 (1997).
Bertrand, S., Weiland, S., Berkovic, S. F., Steinlein, O. K. & Bertrand, D. Properties of neuronal nicotinic acetylcholine receptor mutants from humans suffering from autosomal dominant frontal lobe epilepsy. Br. J. Pharmacol. 125, 751–760 (1998).
Role, L. W. & Berg, D. K. Nicotinic receptors in the development and modulation of CNS synapses. Neuron 16, 1077–1085 (1996).
Wonnacott, S. Presynaptic nicotinic ACh receptors. Trends Neurosci. 20, 92–98 (1997).
Kopeloff, L. M., Barrera, S. E. & Kopeloff, N. Recurrent convulsive seizures in animals produced by immunologic and chemical means. Am. J. Psychiatry 98, 881–902 (1942).
Rasmussen, T., Olszweski, J. & Lloyd-Smith, D. K. Focal seizures due to chronic localized encephalitis. Neurology 8, 435–455 (1958).
Rogers, S. W. et al. Autoantibodies to glutamate receptor GluR3 in Rasmussen's encephalitis. Science 265, 648–651 (1994).
Andrews, P. I., Dichter, M. A., Berkovic, S. F., Newton, M. R. & McNamara, J. O. Plasmapheresis in Rasmussen's encephalitis. Neurology 46, 242–246 (1996).
Antozzi, C. et al. Long-term selective IgG immuno-adsorption improves Rasmussen's encephalitis. Neurology 51, 302–305 (1998).
Twyman, R. E., Gahring, L. C., Spiess, J. & Rogers, S. W. Glutamate receptor antibodies activate a subset of receptors and reveal an agonist binding site. Neuron 14, 755–762 (1995).
He, X. P. et al. Glutamate receptor GluR3 antibodies and death of cortical cells. Neuron 20, 153–163 (1998).
Whitney, K. D., Andrews, P. I. & McNamara, J. O. IgG and complement immunoreactivity in the cerebral cortex of Rasmussen's encephalitis patients. Neurology (in the press).
Li, Y. et al. Local-clonal expansion of infiltrating T lymphocytes in chronic encephalitis of Rasmussen. J. Immunol. 158, 1428–1437 (1997).
O'Hara, P. et al. The ligand-binding domain in metabotropic glutamate receptors is related to bacterial periplasmic binding domains. Neuron 11, 41–52 (1993).
Laxer, K. D. in Chronic Encephalitis and Epilepsy: Rasmussen's Encephalitis (ed. Anderman, F.) 135–140 (Butterworth-Heinemann, Stoneham, MA, 1991).
Ramón y Cajal, S. in Degeneration and Regeneration of the Nervous System (ed. May, R. M.) 656–692 (Oxford Univ. Press, London, 1928).
Sutula, T., He, X. X., Cavazos, J. & Scott, G. Synaptic reorganization in the hippocampus induced by abnormal functional activity. Science 239, 1147–1150 (1988).
Represa, A., Jorquera, I., Le Gal La Salle, G. & Ben-Ari, Y. Epilepsy induced collateral sprouting of hippocampal mossy fibers: does it induce the development of ectopic synapses with granule cell dendrites? Hippocampus 3, 257–268 (1993).
Okazaki, M. M., Evenson, D. A. & Nadler, J. V. Hippocampal mossy fiber sprouting and synapse formation after status epilepticus in rats: visualization after retrograde transport of biocytin. J. Comp. Neurol. 352, 515–534 (1995).
De Lanerolle, N. C., Kim, J. H., Robbins, R. J. & Spencer, D. D. Hippocampal interneuron loss and plasticity in human temporal lobe epilepsy. Brain Res. 495, 387–395 (1989).
Sutula, T., Cascino, G., Cavazos, J., Parada, I. & Ramirez, L. Mossy fiber synaptic reorganization in the epileptic human temporal lobe. Ann. Neurol. 26, 321–330 (1989).
Houser, C. R. et al. Altered patterns of dynorphin immunoreactivity suggest mossy fiber reorganization in human hippocampal epilepsy. J. Neurosci. 10, 267–282 (1990).
Tauck, D. L. & Nadler, J. V. Evidence of functional mossy fiber sprouting in hippocampal formation of kainic acid-treated rats. J. Neurosci. 5, 1016–1022 (1985).
Mello, L. E. A.M. et al. in Molecular Neurobiology of Epilepsy. Epilepsy Research Supplement, Vol. 9 (eds Engel, J., Wasterlain, C., Cavalheiro, E. A., Heinemann, U. & Avanzini, G.) 51–60 (Elsevier Science, Amsterdam, 1992).
Ribak, C. E. & Peterson, G. M. Intragranular mossy fibers in rats and gerbils taken from synapses with the somata and proximal dendrites of basket cells in the dentate gyrus. Hippocampus 1, 355–364 (1991).
Seress, L. in The Dentate Gyrus and its Role in Seizures. Epilepsy Research Supplement, Vol. 7 (eds Ribak, C. E., Gall, C. M. & Mody, I.) 3–28 (Elsevier Science, Amsterdam, 1992).
Doyle, W. K., & Spencer, D. D. in Epilepsy: A Comprehensive Textbook, Vol. 2 (eds Engel, J. & Pedley, T. A.) 1807–1817 (Lippincott-Raven, Philadelphia, 1997).
Amaral, D. G. & Witter, M. P. The three-dimensional organization of the hippocampal formation: a review of anatomical data. Neuroscience 31, 571–591 (1989).
Miles, R. & Wong, R. K. S. Excitatory synaptic interactions between CA3 neurons in the guinea pig hippocampus. J. Physiol. (Lond.) 373, 397–418 (1986).
Collins, R. C., Tearse, R. G. & Lothman, E.W. Functional anatomy of limbic seizures: focal discharges from medial entorhinal cortex in rat. Brain Res. 280, 25–40 (1983).
Behr, J., Gloveli, R., Gutierrez, R. & Heinemann, U. Spread of low Mg2+ induced epileptiform activity from the rat entorhinal cortex to the hippocampus after kindling studied in vitro. Neurosci. Lett. 216, 41–44 (1996).
Wenzel, H. J., Woolley, C. S. & Schwartzkroin, P. A. Kainic acid-induced mossy fiber sprouting and synapse formation in the rat dentate gyrus. Soc. Neurosci. Abstr. 21, 1472 (1995).
Wuarin, J. P. & Dudek, F. E. Electrographic seizures and new recurrent excitatory circuits in the dentate gyrus of hippocampal slices from kainate-treated rats. J. Neurosci. 16, 4438–4448 (1996).
Meldrum, B. S., Vigoroux, R. A. & Brierley, J. B. Systemic factors and epileptic brain damage. Prolonged seizures in paralyzed, artificially ventilated baboons. Arch. Neurol. 29, 82–87 (1973).
Bruton, C. J. The Neuropathology of Temporal Lobe Epilepsy (Oxford Univ. Press, 1988).
Wasterlain, C. G., Fujikawa, D. G., Penix, L. & Sankar, R. Pathophysiological mechanisms of brain damage from status epilepticus. Epilpesia 34, S37–S53 (1993).
Pollard, H. et al. Kainate-induced apoptotic cell death in hippocampal neurons. Neuroscience 63, 7–18 (1994).
Sloviter, R. S., Dean, E., Sollas, A. L. & Goodman, J. H. Apoptosis and necrosis induced in different hippocampal neuron populations by repetitive perforant path stimulation in the rat. J. Comp. Neurol. 366, 516–533 (1996).
Vanlandingham, K. E., Heinz, E. R., Cavazos, J. E. & Lewis, D. V. Magnetic resonance imaging evidence of hippocampal injury after prolonged febrile convulsions. Ann. Neurol. 43, 411–412 (1998).
Cavazos, J. E., Das, I. & Sutula, T. P. Neuronal loss induced in limbic pathways by kindling: evidence for induction of hippocampal sclerosis by repeated brief seizures. J. Neurosci. 14, 3106–3121 (1994).
Watanabe, Y. et al. Null mutation of c-fos impairs structural and functional plasticities in the kindling model of epilepsy. J. Neurosci. 16, 3827–3836 (1996).
Adams, B. et al. Time course for kindling-induced changes in the hilar area of the dentate gyrus: reactive gliosis as a potential mechanism. Brain Res. 804, 331–336 (1998).
Bengzon, J. et al. Apoptosis and proliferation of dentate gyrus neurons after single and intermittent limbic seizures. Proc. Natl. Acad. Sci. USA 94, 10432–10437 (1997).
Parent, J. M. et al. Dentate granule cell neurogenesis is increased by seizures and contributes to aberrant network reorganization in the adult rat hippocampus. J. Neurosci. 17, 3727–3738 (1997).
Parent, J. M., Janumpalli, S., McNamara, J. O. & Lowenstein, D. H. Increased dentate granule cell neurogenesis following amygdala kindling in the adult rat. Neurosci. Lett. 247, 9–12 (1998).
Parent, J. M., Tada, E., Fike, J. R. & Lowenstein, D. H. Whole brain irradiation inhibits dentate granule cell neurogenesis but not seizure-induced mossy fiber sprouting in adult rats. Soc. Neurosci. Abstr. 24, 1934 (1998).
Morgan, J. I. & Curran, T. Stimulus-transcription coupling in the nervous system: involvement of the inductible proto-oncogenes fos and jun. Annu. Rev. Neurosci. 14, 421–451 (1991).
Labiner, D.M. et al. Induction of c-fos mRNA by kindled seizures: complex relationship with neuronal burst firing. J. Neurosci. 13, 744–751 (1993).
Gall, C. M. & Isackson, P. J. Limbic seizures increase neuronal production of messengerRNAfor nerve growth factor. Science 245, 758–761 (1989).
Ernfors, P., Bengzon, J., Kokaia, Z., Persson, H. & Lindvall, O. Increased levels of messenger RNAs for neurotrophic factors in the brain during kindling epileptogenesis. Neuron 7, 165–176 (1991).
Bendotti, C., Vezzani, A., Tarizzo, G. & Samanin, R. Increased expression of GAP-43, somatostatin and neuropeptide YmRNA in the hippocampus during development of hippocampal kindling in rats. Eur. J. Neurosci. 5, 1312–1320 (1993).
Laurberg, S. & Zimmer, J. Lesion-induced sprouting of hippocampal mossy fiber collaterals to the fascia dentata in developing and adult rats. J. Comp. Neurol. 200, 433–459 (1981).
Adams, B., Lee, M., Fahnestock, M. & Racine, R. J. Long-term potentiation trains induce mossy fiber sprouting. Brain Res. 775, 193–197 (1997).
McKinney, R. A., Debanne, D., Gahwiler, B. H. & Thompson, S. M. Lesion-induced axonal sprouting and hyperexcitability in the hippocampus in vitro: implications for the genesis of post-traumatic epilepsy. Nature Med. 3, 990–996 (1997).
Perez, Y., Morin, F., Beaulieu, C. & Lacaille, J. C. Axonal sprouting of CA1 pyramidal cells in hyperexcitable hippocampal slices of kainate-treated rats. Eur. J. Neurosci. 8, 736–748 (1996).
Bausch, S. B., Womack, M. D., Augustine, G. J. & McNamara, J. O. Rearrangements in hippocampal circuitry underlie hyperexcitability in normal and kainic acid treated hippocampal slice cultures. Soc. Neurosci. Abstr. 24, 1936 (1998).
Salin, P., Tseng, G. F., Hoffman, S., Parada, I. & Prince, D. A. Axonal sprouting in layer V pyramidal neurons of chronically injured cerebral cortex. J. Neurosci. 15, 8234–8245 (1995).
Sutula, T. et al. Synaptic and axonal remodeling of mossy fibers in the hilus and suprgranular region of the dentate gyrus in kainate-treated rats. J. Comp. Neurol. 390, 578–594 (1998).
Merritt, H. H. & Putnam, T. J. A new series of anticonvulsant drugs tested by experiments on animals. Arch. Neurol. Psychiatry 39, 1003–1015 (1938).
Merritt, H. H. & Putnam, T. J. Sodium diphenyl hydantoinate in treatment of convulsive disorders. J. Am. Med. Assoc. 111, 1068–1073 (1938).
McLean, M. J. & Macdonald, R. L. Multiple actions of phenytoin on mouse spinal cord neurons in cell culture. J. Pharmacol. Exp. Ther. 227, 779–789 (1983).
Ayala, G. F., Dichter, M., Gumnit, R. J., Matsumoto, H. & Spencer, W. A. Genesis of epileptic interictal spikes. New knowledge of cortical feedback systems suggests a neurophysiological explanation of brief paroxysms. Brain Res. 52, 1–17 (1973).
Traynelis, S. F. & Dingledine, R. Potassium-induced spontaneous electrographic seizures in the rat hippocampal slice. J. Neurophysiol. 59, 259–276 (1988).
McNamara, J. O. in Goodman & Gilman's The Pharmacological Basis of Therapeutics, 9th edn (eds Hardman, J. G. & Limbird, L. L.) 461–486 (McGraw-Hill, New York, 1996).
Acknowledgements
I thank K. Whitney and S. Danzer for reading versions of this manuscript and M. Routbort for assistance with the figures. This work was supported by grants from theNational Institutes of Neurological Disease and Stroke and by a grant from the Department of Veterans Affairs.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
McNamara, J. Emerging insights into the genesis of epilepsy. Nature 399, A15–A22 (1999). https://doi.org/10.1038/399a015
Issue Date:
DOI: https://doi.org/10.1038/399a015
This article is cited by
-
Decoding Epileptic Seizures: Exploring In Vitro Approaches to Unravel Pathophysiology and Propel Future Therapeutic Breakthroughs
Biomedical Materials & Devices (2024)
-
Neuroinflammatory mediators in acquired epilepsy: an update
Inflammation Research (2023)
-
Black-Box Warnings of Antiseizure Medications: What is Inside the Box?
Pharmaceutical Medicine (2023)
-
Absence of Claudin 11 in CNS Myelin Perturbs Behavior and Neurotransmitter Levels in Mice
Scientific Reports (2018)
-
Inhibition of Acid Sensing Ion Channel 3 Aggravates Seizures by Regulating NMDAR Function
Neurochemical Research (2018)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.