Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Emerging insights into the genesis of epilepsy

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

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Synaptic reorganization of epileptic hippocampus

References

  1. Adams, R. D., Victor, M. & Ropper, A. H. Principles of Neurology, 6th edn 1–317 (McGraw-Hill, New York, 1997).

    Google Scholar 

  2. 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).

  3. Berkovic, S. in Epilepsy: AComprehensive Textbook (eds Engel, J. & Pedley, T. A.) 217–224 (Lippincott- Raven, Philadelphia, 1997).

    Google Scholar 

  4. Puranam, R. S. & McNamara, J. O. Seizure disorders in mutant mice: relevance to human epilepsies. Curr. Opin. Neurobiol. (in the press).

  5. Pennacchio, L. A. et al. Mutations in the gene encoding cystatin B in progressive myoclonus epilepsy (EPM1). Science 271, 1731–1734 (1996).

    Article  ADS  CAS  PubMed  Google Scholar 

  6. Fox, J. W. et al. Mutations in filamin 1 prevent migration of cerebral cortical neurons in human periventricular heterotopia. Neuron 21, 1315–1325 (1998).

    Article  CAS  PubMed  Google Scholar 

  7. 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).

    Article  CAS  PubMed  Google Scholar 

  8. 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).

    Article  CAS  PubMed  Google Scholar 

  9. 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).

    Article  CAS  PubMed  Google Scholar 

  10. Biervert, C. et al. Apotassiumchannelmutation in neonatal human epilepsy. Science 279, 403–406 (1998).

    Article  ADS  CAS  PubMed  Google Scholar 

  11. 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).

    Article  CAS  PubMed  Google Scholar 

  12. 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).

    Article  CAS  PubMed  Google Scholar 

  13. Leppert, M. et al. Benign familial neonatal convulsions linked to genetic markers on chromosome 20. Nature 337, 647–648 (1989).

    Article  ADS  CAS  PubMed  Google Scholar 

  14. 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).

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Wang, Q. et al. Positional cloning of a novel potassium channel gene: KVLQT1 mutations cause cardiac arrhythmias. Nature Genet. 12, 17–23 (1996).

    Article  PubMed  Google Scholar 

  16. 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).

    Article  CAS  PubMed  Google Scholar 

  17. 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).

    Article  ADS  CAS  PubMed  Google Scholar 

  18. 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).

    Article  CAS  PubMed  Google Scholar 

  19. 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).

    Article  CAS  PubMed  Google Scholar 

  20. 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).

    Article  CAS  PubMed  Google Scholar 

  21. Phillips, H. A. et al. Genetic heterogeneity and evidence for a second locus at 15q24. Am. J. Hum. Genet. 63, 1108–1116 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. 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).

    Article  CAS  PubMed  Google Scholar 

  23. 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).

    Article  CAS  PubMed  Google Scholar 

  24. 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).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Role, L. W. & Berg, D. K. Nicotinic receptors in the development and modulation of CNS synapses. Neuron 16, 1077–1085 (1996).

    Article  CAS  PubMed  Google Scholar 

  26. Wonnacott, S. Presynaptic nicotinic ACh receptors. Trends Neurosci. 20, 92–98 (1997).

    Article  CAS  PubMed  Google Scholar 

  27. 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).

    Article  CAS  Google Scholar 

  28. Rasmussen, T., Olszweski, J. & Lloyd-Smith, D. K. Focal seizures due to chronic localized encephalitis. Neurology 8, 435–455 (1958).

    Article  CAS  PubMed  Google Scholar 

  29. Rogers, S. W. et al. Autoantibodies to glutamate receptor GluR3 in Rasmussen's encephalitis. Science 265, 648–651 (1994).

    Article  ADS  CAS  PubMed  Google Scholar 

  30. 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).

    Article  CAS  PubMed  Google Scholar 

  31. Antozzi, C. et al. Long-term selective IgG immuno-adsorption improves Rasmussen's encephalitis. Neurology 51, 302–305 (1998).

    Article  CAS  PubMed  Google Scholar 

  32. 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).

    Article  CAS  PubMed  Google Scholar 

  33. He, X. P. et al. Glutamate receptor GluR3 antibodies and death of cortical cells. Neuron 20, 153–163 (1998).

    Article  CAS  PubMed  Google Scholar 

  34. 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).

  35. Li, Y. et al. Local-clonal expansion of infiltrating T lymphocytes in chronic encephalitis of Rasmussen. J. Immunol. 158, 1428–1437 (1997).

    CAS  PubMed  Google Scholar 

  36. 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).

    Article  CAS  PubMed  Google Scholar 

  37. Laxer, K. D. in Chronic Encephalitis and Epilepsy: Rasmussen's Encephalitis (ed. Anderman, F.) 135–140 (Butterworth-Heinemann, Stoneham, MA, 1991).

    Google Scholar 

  38. Ramón y Cajal, S. in Degeneration and Regeneration of the Nervous System (ed. May, R. M.) 656–692 (Oxford Univ. Press, London, 1928).

    Google Scholar 

  39. Sutula, T., He, X. X., Cavazos, J. & Scott, G. Synaptic reorganization in the hippocampus induced by abnormal functional activity. Science 239, 1147–1150 (1988).

    Article  ADS  CAS  PubMed  Google Scholar 

  40. 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).

    Article  CAS  PubMed  Google Scholar 

  41. 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).

    Article  CAS  PubMed  Google Scholar 

  42. 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).

    Article  CAS  PubMed  Google Scholar 

  43. 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).

    Article  CAS  PubMed  Google Scholar 

  44. Houser, C. R. et al. Altered patterns of dynorphin immunoreactivity suggest mossy fiber reorganization in human hippocampal epilepsy. J. Neurosci. 10, 267–282 (1990).

    Article  CAS  PubMed  Google Scholar 

  45. 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).

    Article  CAS  PubMed  Google Scholar 

  46. 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).

    Google Scholar 

  47. 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).

    Article  CAS  PubMed  Google Scholar 

  48. 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).

    Google Scholar 

  49. 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).

    Google Scholar 

  50. Amaral, D. G. & Witter, M. P. The three-dimensional organization of the hippocampal formation: a review of anatomical data. Neuroscience 31, 571–591 (1989).

    Article  CAS  PubMed  Google Scholar 

  51. Miles, R. & Wong, R. K. S. Excitatory synaptic interactions between CA3 neurons in the guinea pig hippocampus. J. Physiol. (Lond.) 373, 397–418 (1986).

    Article  CAS  Google Scholar 

  52. 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).

    Article  CAS  PubMed  Google Scholar 

  53. 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).

    Article  CAS  PubMed  Google Scholar 

  54. 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).

    Google Scholar 

  55. 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).

    Article  CAS  PubMed  Google Scholar 

  56. 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).

    Article  CAS  PubMed  Google Scholar 

  57. Bruton, C. J. The Neuropathology of Temporal Lobe Epilepsy (Oxford Univ. Press, 1988).

    Google Scholar 

  58. Wasterlain, C. G., Fujikawa, D. G., Penix, L. & Sankar, R. Pathophysiological mechanisms of brain damage from status epilepticus. Epilpesia 34, S37–S53 (1993).

    Article  Google Scholar 

  59. Pollard, H. et al. Kainate-induced apoptotic cell death in hippocampal neurons. Neuroscience 63, 7–18 (1994).

    Article  CAS  PubMed  Google Scholar 

  60. 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).

    Article  CAS  PubMed  Google Scholar 

  61. 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).

    Article  Google Scholar 

  62. 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).

    Article  CAS  PubMed  Google Scholar 

  63. 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).

    Article  CAS  PubMed  Google Scholar 

  64. 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).

    Article  CAS  PubMed  Google Scholar 

  65. 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).

    Article  ADS  CAS  PubMed  Google Scholar 

  66. 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).

    Article  CAS  PubMed  Google Scholar 

  67. 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).

    Article  CAS  PubMed  Google Scholar 

  68. 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).

    Google Scholar 

  69. 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).

    Article  CAS  PubMed  Google Scholar 

  70. 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).

    Article  CAS  PubMed  Google Scholar 

  71. Gall, C. M. & Isackson, P. J. Limbic seizures increase neuronal production of messengerRNAfor nerve growth factor. Science 245, 758–761 (1989).

    Article  ADS  CAS  PubMed  Google Scholar 

  72. 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).

    Article  CAS  PubMed  Google Scholar 

  73. 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).

    Article  CAS  PubMed  Google Scholar 

  74. 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).

    Article  CAS  PubMed  Google Scholar 

  75. Adams, B., Lee, M., Fahnestock, M. & Racine, R. J. Long-term potentiation trains induce mossy fiber sprouting. Brain Res. 775, 193–197 (1997).

    Article  CAS  PubMed  Google Scholar 

  76. 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).

    Article  CAS  PubMed  Google Scholar 

  77. 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).

    Article  CAS  PubMed  Google Scholar 

  78. 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).

    Google Scholar 

  79. 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).

    Article  CAS  PubMed  Google Scholar 

  80. 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).

    Article  CAS  PubMed  Google Scholar 

  81. Merritt, H. H. & Putnam, T. J. A new series of anticonvulsant drugs tested by experiments on animals. Arch. Neurol. Psychiatry 39, 1003–1015 (1938).

    Article  CAS  Google Scholar 

  82. Merritt, H. H. & Putnam, T. J. Sodium diphenyl hydantoinate in treatment of convulsive disorders. J. Am. Med. Assoc. 111, 1068–1073 (1938).

    Article  Google Scholar 

  83. 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).

    CAS  PubMed  Google Scholar 

  84. 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).

    Article  CAS  PubMed  Google Scholar 

  85. Traynelis, S. F. & Dingledine, R. Potassium-induced spontaneous electrographic seizures in the rat hippocampal slice. J. Neurophysiol. 59, 259–276 (1988).

    Article  CAS  PubMed  Google Scholar 

  86. 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).

    Google Scholar 

Download references

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

Authors

Rights and permissions

Reprints 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

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1038/399a015

This article is cited by

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.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing