Experimental absence seizures: potential role of γ-hydroxybutyric acid and GABAB receptors

  • R. Bernasconi
  • J. Lauber
  • C. Marescaux
  • M. Vergnes
  • P. Martin
  • V. Rubio
  • T. Leonhardt
  • N. Reymann
  • H. Bittiger
Part of the Journal of Neural Transmission book series (NEURAL SUPPL, volume 35)


We have investigated whether the pathogenesis of spontaneous generalized non-convulsive seizures in rats with genetic absence epilepsy is due to an increase in the brain levels of γ-hydroxybutyric acid (GHB) or in the rate of its synthesis. Concentrations of GHB or of its precursor γ-butyrolactone (GBL) were measured with a new GC/MS technique which allows the simultaneous assessment of GHB and GBL. The rate of GHB synthesis was estimated from the increase in GHB levels after inhibition of its catabolism with valproate. The results of this study do not indicate significant differences in GHB or GBL levels, or in their rates of synthesis in rats showing spike-and-wave discharges (SWD) as compared to rats without SWD. Binding data indicate that GHB, but not GBL, has a selective, although weak affinity for GABAB receptors (IC50 = 150 µM). Similar IC50 values were observed in membranes prepared from rats showing SWD and from control rats. The average GHB brain levels of 2.12 ± 0.23 nmol/g measured in the cortex and of 4.28 ± 0.90 nmol/g in the thalamus are much lower than the concentrations necessary to occupy a major part of the GABAB receptors. It is unlikely that local accumulations of GHB reach concentrations 30–70-fold higher than the average brain levels. After injection of 3.5 mmol/kg GBL, a dose sufficient to induce SWD, brain concentrations reach 240 ± 31 nmol/g (Snead, 1991) and GHB could thus stimulate the GABAB receptor.

Like the selective and potent GABAB receptor agonist R(-)-baclofen, GHB causes a dose-related decrease in cerebellar cGMP. This decrease and the increase in SWD caused by R(-)-baclofen were completely blocked by the selective and potent GABAB receptor antagonist CGP 35348, whereas only the increase in the duration of SWD induced by GHB was totally antagonized by CGP 35348. The decrease in cerebellar cGMP levels elicited by GHB was only partially antagonized by CGP 35348.

These findings suggest that all effects of R(-)-baclofen are mediated by the GABAB receptor, whereas only the induction of SWD by GHB is dependent on GABAB receptor mediation, the decrease in cGMP being only partially so. Taken together with the observations of Marescaux et al. (1992), these results indicate that GABAB receptors are of primary importance in experimental absence epilepsy and that GABAB receptor antagonists may represent a new class of anti-absence drugs.


GABAB Receptor Absence Seizure cGMP Level Absence Epilepsy GABAB Receptor Agonist 
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  1. Albin RL, Gilman S (1989) Parasagittal zonation of GABAB receptors in molecular layer of rat cerebellum. Eur J Pharmacol 173: 113–114PubMedCrossRefGoogle Scholar
  2. Avoli M, Gloor P (1982) Interaction of cortex and thalamus in spike and wave discharges of feline generalized penicillin epilepsy. Exp Neurol 76: 196–217PubMedCrossRefGoogle Scholar
  3. Beaumont K, Chilton WS, Yamamura HI, Enna SJ (1978) Muscimol binding in rat brain: association with synaptic GABA receptors. Brain Res 148: 153–162PubMedCrossRefGoogle Scholar
  4. Bernasconi R, Jones RSG, Bittiger H, Olpe HR, Heid J, Martin P, Klein M, Loo P, Braunwalder A, Schmutz M (1986) Does pipecolic acid interact with the central GABA-ergic system? J Neural Transm 67: 175–189PubMedCrossRefGoogle Scholar
  5. Bittiger H (1982) Substance P receptors in the nervous system and possible receptors subtypes (discussion). In: Porter R, O’Connor M (eds) Substance P in the nervous system. Ciba Foundation symposium 91. Pitman, London, pp 196–201Google Scholar
  6. Bittiger H, Reymann N, Hall R, Kane P (1988) CGP 27492, a new, potent and selective radioliogand for GABAB receptors. In: Proceedings of the 11th Annual Meeting of the European Neuroscience Association. Zürich, September 1988. Eur J Neurosci [Suppl]: Abstr. 16. 10Google Scholar
  7. Bittiger H, Froestl W, Hall R, Karlsson G, Klebs K, Olpe HR, Pozza M, Steinmann M, Van Riezen H (1990) Biochemistry, electrophysiology and pharmacology of a new GABAB antagonist: CGP 35348. In: Bowery N, Bittiger H, Olpe HR (eds) GABAB receptors in mammalian function. J Wiley, Chichester, pp 47–60Google Scholar
  8. Bowery NG, Hudson AL, Price GW (1987) GABAA and GABAB receptor site distribution in the rat central nervous system. Neuroscience 20: 365–383PubMedCrossRefGoogle Scholar
  9. Bradbury AF, Smyth DG, Snell CR, Birdsall NJ, Hulme EC (1976) C-fragment of lipotropin has a high affinity for brain opiate receptors. Nature 260: 793–795CrossRefGoogle Scholar
  10. Bylund DB, Snyder SH (1976) Beta adrenergic receptor binding in membrane preparation from mammalian brain. Mol Pharmacol 12: 568–580PubMedGoogle Scholar
  11. Crunelli V, Leresche N (1991) A role for GABAB receptors in excitation and inhibition of thalamocortical cells. Trends Neurosci 14: 16–21PubMedCrossRefGoogle Scholar
  12. Eli M, Cattabeni F (1983) Endogenous y-hydroxybutyrate in rat brain areas: postmortem changes and effects of drugs interfering with y-aminobutyric acid metabolism. J Neurochem 41: 524–530PubMedCrossRefGoogle Scholar
  13. Ehrhardt JD, Vayer P, Maitre M (1988) A rapid and sensitive method for the determination of y-hydroxybutyric acid and trans-y-hydroxycrotonic acid in rat brain tissue by gas chromatography/mass spectrometry with negative ion detection. Biomed Environ Mass Spectrom 15: 521–524PubMedCrossRefGoogle Scholar
  14. Engel J, Ochs RF, Gloor P (1990) Metabolic studies of generalized epilepsy. In: Avoli M, Gloor P, Kostopoulos G, Naquet R (eds) Generalized epilepsy: neuro-biological approaches. Birkhäuser, Boston, pp 387–396Google Scholar
  15. Enna SJ, Snyder SH (1975) Properties of gamma-aminobutyric acid ( GABA) receptor binding in ra brain synaptic membrane fractions. Brain Res 100: 81–97PubMedCrossRefGoogle Scholar
  16. Fariello RG, Golden GT (1987) The THIP-induced model of bilateral synchronous spike and wave in rodents. Neuropharmacology 26: 161–165PubMedCrossRefGoogle Scholar
  17. Fromm GH, Kohli CM (1972) The role of inhibitory pathways in petit mal epilepsy. Neurology 22: 1012–1020PubMedGoogle Scholar
  18. Gloor P, Fariello RG (1988) Generalized epilepsy: some of its cellular mechanisms differ from those of focal epilepsy. Trends Neurosci 11: 63–68PubMedCrossRefGoogle Scholar
  19. Glowinski J, Iversen LL (1966) Regional studies of catecholamines in the rat brain-I. The disposition of [3H]norepinephrine, [3H]dopamine and [3H]DOPA in various regions of the brain. J Neurochem 13: 655–669PubMedCrossRefGoogle Scholar
  20. Godschalk M, Dzoljic MR, Bonta IL (1976) Antagonism of gamma-hydroxybutyrateinduced hypersynchronization in the ECoG of the rat by anti-petit mal drugs. Neurosci Lett 3: 145–150PubMedCrossRefGoogle Scholar
  21. Godschalk M, Dzoljic MR, Bonta IL (1977) Slow wave sleep and a state resembling absence epilepsy induced in the rat by 7-hydroxybutyrate. Eur J Pharmacol 44: 105–111PubMedCrossRefGoogle Scholar
  22. Gold BL, Roth RH (1977) Kinetics of in vivo conversion of gamma [3H]aminobutyric acid to gamma [3H]hydroxybutyric acid in rat brain. J Neurochem 28: 1069–1073PubMedCrossRefGoogle Scholar
  23. Greengrass P, Bremner R (1979) Binding characteristics of 3H-prazosin to rat brain alpha-adrenergic receptors. Eur J Pharmacol 55: 323–326PubMedCrossRefGoogle Scholar
  24. Grob K (1986) Making and manipulating capillary columns for gas chromatography. Huethig, Basel New YorkGoogle Scholar
  25. Gumulka SW, Dinnendahl V, Schonhoffer PS (1979) Baclofen and cerebellar cyclic GMP levels in mice. Pharmacology 19: 75–81PubMedCrossRefGoogle Scholar
  26. King GA (1979) Effects of systemically applied GABA agonists and antagonists on wave-spike ECoG activity in rat. Neuropharmacology 18: 47–55PubMedCrossRefGoogle Scholar
  27. Marescaux C, Micheletti G, Vergnes M, Depaulis A, Rumbach L, Warter JM (1984) A model of chronic spontaneous petit mal-like seizures in the rat: comparison with pentylenetetrazol-induced seizures. Epilepsia 25: 326–331PubMedCrossRefGoogle Scholar
  28. Marescaux C, Vergnes M, Bernasconi R (1992) GABAB receptor antagonists: potential new anti-absence drugs (this volume)Google Scholar
  29. Meldrum B (1981) GABA-agonists as anti-epileptic agents. In: Costa E, Di Chiara G, Gessa GL (eds) GABA and benzodiazepine receptors. Adv Biochem Psychopharmacol 26: 207–217Google Scholar
  30. Micheletti G, Marescaux C, Vergnes M, Rumbach L, Warter JM (1985) Effects of GABA-mimetics and GABA antagonists on spontaneous nonconvulsive seizures in Wistar rats. In: Bartholoni G, Bossi L, Lloyd KG, Morselli PL (eds) Epilepsy and GABA receptor agonists. Raven Press, New York, pp 129–137Google Scholar
  31. Mirsky AF, Duncan CC, Myslobodsky MS (1986) Petit mal epilepsy: a review and integration of recent information. J Clin Neurophysiol 3: 179–208PubMedGoogle Scholar
  32. Nelson PL, Herbert A, Bourgoin S, Glowinski J, Hamon M (1978) Characteristics of central 5-HT receptors and their adaptive changes following intracerebral 5,7dihydroxytryptamine administration in the rat. Mol Pharmacol 14: 983–995PubMedGoogle Scholar
  33. Patel J, Marangos PJ, Stivers J, Goodwin FK (1982) Characterization of adenosine receptors in brain using N6 cyclohexyl [3H]adenosine. Brain Res 237: 203–214PubMedCrossRefGoogle Scholar
  34. Pericic D, Eng N, Walters JR (1978) Post-mortem and aminooxyacetic acid-induced accumulation of GABA: effect of gamma-butyrolactone and picrotoxin. J Neurochem 30: 767–773PubMedCrossRefGoogle Scholar
  35. Rumigny JF, Maitre M, Cash C, Mandel P (1980) Specific and non-specific succinic semialdehyde reductases from rat brain: isolation and properties. FEBS Lett 117: 111–116PubMedCrossRefGoogle Scholar
  36. Smith KA, Bierkamper GG (1990) Paradoxical role of GABA in a chronic model of petit mal (absence)-like epilepsy in the rat. Eur J Pharmacol 176: 45–55PubMedCrossRefGoogle Scholar
  37. Snead OC (1977) Gamma hydroxybutyrate. Life Sci 20: 1935–1943PubMedCrossRefGoogle Scholar
  38. Snead OC (1988) y-Hydroxybutyrate model of generalized absence seizures: further characterization and comparison with comparison with other absence models. Epilepsia 29: 361–368PubMedCrossRefGoogle Scholar
  39. Snead OC (1990) The ontogeny of GABAergic enhancement of the y-hydroxybutyrate model of generalized absence seizures. Epilepsia 31: 363–368PubMedCrossRefGoogle Scholar
  40. Snead OC (1991) The y-hydroxybutyrate model of absence seizures: correlation of regional brain levels of y-hydroxybutyric acid and y-butyrolactone with spike wave discharges. Neuropharmacology 30: 161–167PubMedCrossRefGoogle Scholar
  41. Snead OC, Yu RR, Huttenlocher RR (1976) y-Hydroxybutyrate: correlation of serum and cerebrospinal fluid levels with electroencephalographic and behavioural effects. Neurology 26: 51–56PubMedGoogle Scholar
  42. Snead OC, Bearden LH, Pegram V (1980) Effect of acute and chronic anticonvulsant administration on endogenous gamma-hydroxybutyrate in rat brain. Neuropharmacology 19: 47–52PubMedCrossRefGoogle Scholar
  43. Snead OC, Liu CC, Bearden LJ (1982) Studies on the relation of y-hydroxybutyric acid (GHB) to y-aminobutyric acid (GABA). Biochem Pharmacol 31: 3917–3923PubMedCrossRefGoogle Scholar
  44. Snead OC, Fumer R, Liu CC (1989) In vivo conversion of y-aminobutyric acid and 1,4,butanediol to y-hydroxybutyric acid in rat brain: studies using stable isotopes. Biochem Pharmacol 38: 4375–4380PubMedCrossRefGoogle Scholar
  45. Snead OC, Hechler V, Vergnes M, Marescaux C, Maitre M (1990) Increased yhydroxybutyric acid receptors in thalamus of a genetic animal model of petit mal epilepsy. Epilepsy Res 7: 121–128PubMedCrossRefGoogle Scholar
  46. Speth RC, Wastek GJ, Johnson PC, Yamamura HI (1978) Benzodiazepine binding in human brain; characterization using 3H-flunitrazepam. Life Sci 22: 859–866PubMedCrossRefGoogle Scholar
  47. Steriade M, Llinas R (1988) The functional states of the thalamus and the associated neuronal interplay. Physiol Rev 68: 649–742PubMedGoogle Scholar
  48. Tanaka T, Starke K (1980) Antagonist/agonist preferring alpha-adrenoceptors or alphal/alpha2-adrenoceptors? Eur J Pharmacol 63: 191–194PubMedCrossRefGoogle Scholar
  49. Tran VT, Lebovitz R, Toll L, Snyder SH (1981) [3H]Doxepine interactions with histamine H1 receptors and other sites in guinea pig and rat brain homogenates. Eur J Pharmacol 70: 501–509PubMedCrossRefGoogle Scholar
  50. Vayer P, Mandel P, Maitre M (1987) Gamma-hydroxybutyrate, a possible neurotransmitter. Life Sci 41: 1547–1557PubMedCrossRefGoogle Scholar
  51. Vayer P, Ehrhardt J-D, Gobaille S, Mandel P, Maitre M (1988) Gammahydroxybutyrate distribution and turnover rates in discrete brain regions of the rat. Neurochem Int 12: 53–59PubMedCrossRefGoogle Scholar
  52. Vergnes M, Marescaux C, Micheletti G, Reis J, Depaulis A, Rumbach L, Warter JM (1982) Spontaneous paroxysmal electroclinical patterns in rat: a model of generalized non-convulsive epilepsy. Neurosci Lett 33: 97–101PubMedCrossRefGoogle Scholar
  53. Vergnes M, Marescaux C, Micheletti G, Depaulis A, Rumbach L, Warter JM (1984) Enhancement of spike and wave discharges by GABAmimetic drugs in rats with spontaneous petit-mal-like epilepsy. Neurosci Lett 44: 91–94PubMedCrossRefGoogle Scholar
  54. Vergnes M, Marescaux C, Depaulis A, Micheletti G, Warter JM (1987) Spontaneous spike and wave discharges in thalamus and cortex in a rat model of genetic petit mal-like seizures. Exp Neurol 96: 127–136PubMedCrossRefGoogle Scholar
  55. Vergnes M, Marescaux C, Depaulis A, Micheletti G, Warter JM (1990) Spontaneous spike-and-wave discharges in Wistar rats: a model of genetic generalized non-convulsive epilepsy. In: Avoli M, Gloor P, Kostopoulos G, Naquet R (eds) Generalized epilepsy: neurobiological approaches. Birkhäuser, Boston, pp 238–253Google Scholar
  56. Winer BJ (1971) Statistical principles in experiment design. McGraw-Hill, New York, p 201Google Scholar
  57. Wood P (1991) Pharmacology of the second messenger, cyclic guanosine 3’,5’monophosphate, in the cerebellum. Pharmacol Rev 43: 1–25PubMedCrossRefGoogle Scholar
  58. Yamamura HI, Snyder SH (1974) Muscarinic cholinergic binding in rat brain. Proc Natl Acad Sci 71: 1725–1729PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • R. Bernasconi
    • 1
    • 4
  • J. Lauber
    • 1
  • C. Marescaux
    • 2
  • M. Vergnes
    • 3
  • P. Martin
    • 1
  • V. Rubio
    • 1
  • T. Leonhardt
    • 1
  • N. Reymann
    • 1
  • H. Bittiger
    • 1
  1. 1.Research and Development Department, Pharmaceuticals DivisionCiba-GeigyBaselSwitzerland
  2. 2.Groupe de Recherche de Physiologie Nerveuse, Clinique NeurologiqueHospices CivilsStrasbourgFrance
  3. 3.Centre de Neurochimie du CNRS et de l’INSERMStrasbourgFrance
  4. 4.Research and Development Department, Pharmaceuticals DivisionCiba-Geigy Ltd.BaselSwitzerland

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