Abstract
To elucidate the cellular action of tiagabine, an inhibitor of GAT-1 GABA transporter, in the globus pallidus, whole-cell patch-clamp recordings were made from rat globus pallidus neurons in the acutely prepared brain slice. Superfusion of tiagabine significantly prolonged the decay kinetics of both action potential-dependent and -independent (tetrodotoxin-resistant) inhibitory postsynaptic currents (IPSCs) that were mediated by GABAA receptors. Furthermore, it decreased the frequency of these IPSCs. The latter effect was reversed by the GABAB receptor antagonist CGP55845, which alone had no effect, suggesting the involvement of presynaptic GABAB receptors. Thus, tiagabine could inhibit or disinhibit globus pallidus neurons by increasing the activation of the GABAA receptors and presynaptic GABAB receptors, respectively. In the behaving animal, tiagabine when injected unilaterally into the globus pallidus caused consistent ipsilateral rotation of the rats indicative of increased inhibition of globus pallidus activity. This finding could be explained by the proposition that in the presence of tiagabine, prolonged action of GABA on GABA receptors would dominate over the inhibitory effect of tiagabine on GABA release. Our findings on the electrophysiological and behavioral effects of tiagabine in globus pallidus suggest that this basal ganglia nucleus is one of the sites of action of tiagabine and provides a rationale for investigating its involvement in epilepsy.
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Aiko Y, Hosokawa S, Shima F, Kato M, Kitamura K (1988) Alterations in local cerebral glucose utilization during electrical stimulation of the striatum and globus pallidus in rats. Brain Res 442:43–52
André V, Pineau N, Motte J, Marescauz C, Nehlig A (1998) Mapping of neuronal networks underlying generalized seizures induced by increasing doses of pentylenetetrazole in the immature and adult rat: a c-fos immunohistochemical study. Eur J Neurosci 10:2094–2106
Bolam P, Hanley JJ, Booth PAC, Bevan MD (2000) Synaptic organization of the basal ganglia. J Anat 196:527–542
Borden LA (1996) GABA transporter heterogeneity: pharmacology and cellular localization. Neurochem Int 29:335–356
Borden LA, Dhar TGM, Smith KE, Weinshank RL, Branchek TA, Gluchowski C (1994) Tiagabine, SK&F 89976-A, CI-966, and NNC-711 are selective for the cloned GABA transporter GAT-1. Eur J Pharmacol 269:219–224
Chan PKY, Yung WH (1999) Inhibitory postsynaptic currents of rat substantia nigra pars reticulata neurons: role of GABA receptors and GABA uptake. Brain Res 838:18–26
Charara A, Heilman C, Levey AI, Smith Y (2000) Pre- and postsynaptic localization of GABAB receptors in the basal ganglia in monkeys. Neuroscience 95:127–140
Chen L, Chan SCY, Yung WH (2002) Rotational behavior and electrophysiological effects induced by GABAB receptor activation in rat globus pallidus. Neuroscience 114:417–425
Cooper AJ, Stanford IM (2000) Electrophysiological and morphological characteristics of three subtypes of rat globus pallidus neurone in vitro. J Physiol (Lond) 527:291–304
Crawford P, Meinardi H, Brown S, Rentmeester TW, Pedersen B, Pedersen PC, Lassen LC (2001) Tiagabine: efficacy and safety in adjunctive treatment of partial seizures. Epilepsia 42:531–538
Dalby NO (2000) GABA-level increasing and anticonvulsant effects of three different GABA uptake inhibitors. Neuropharmacology 39:2399–2407
Dalby NO, Nielsen EB (1997) Comparison of the preclinical anticonvulsant profiles of tiagabine, lamotrigine, gabapentin and vigabatrin. Epilepsy Res 28:63–72
Depaulis A, Vergnes M, Marescaux C (1993) Endogenous control of epilepsy: the nigral inhibitory system. Prog Neurobiol 42:33–52
Deransart C, Riban V, Lê B-T, Hechler V, Marescauz C, Depaulis A (1999) Evidence for the involvement of the pallidum in the modulation of seizures in a genetic model of absence epilepsy in the rat. Neurosci Lett 265:131–134
Fink-Jensen A, Suzdak PD, Swedberg MDB, Judge ME, Hansen L, Nielsen PG (1992) The γ-aminobutyric acid (GABA) uptake inhibitor, tiagabine, increases extracellular brain levels of GABA in awake rats. Eur J Pharmacol 220:197–201
Gale K (1989) GABA in epilepsy: the pharmacological basis. Epilepsia (Suppl 3) 30:1–11
Genton P, Guerrini R, Perucca E (2001) Tiagabine in clinical practice. Epilepsia (Suppl 3) 42:42–45
Haugvicova R, Skutova M, Kubova H, Suchomelova L, Mares P (2000) Two different anticonvulsant actions of tiagabine in developing rats. Epilepsia 41:1375–1381
Iadarola MJ, Gale K (1982) Substantia nigra: site of anti-convulsant activity mediated by gamma-aminobutyric acid. Science 218:1237–1240
Ikegaki N, Saito N, Hashima M, Tanaka C (1994) Production of specific antibodies against GABA transporter subtypes (GAT1, GAT2, GAT3) and their application to immunohistochemistry. Mol Brain Res 26:47–54
Jackson MF, Esplin B, Capek R (1999) Activity-dependent enhancement of hyperpolarizing and depolarizing gamma-aminobutyric acid (GABA) synaptic responses following inhibition of GABA uptake by tiagabine. Epilepsy Res 37: 25–36
Nambu A, Llinas R (1994) Electrophysiology of globus pallidus neurons in vitro. J Neurophysiol 72:1127–1139
Nielsen EB, Suzdak PD, Andersen KE, Knutsen LJS, Sonnewald U, Braestrup C (1991) Characterization of tiagabine (NO-328), a new potent and selective GABA uptake inhibitor. Eur J Pharmacol 196:257–266
Paxinos G, Watson C (1986) The rat brain in stereotaxic coordinates. Academic, New York
Radian R, Ottersen OP, Castel M, Kanner B (1990) Immunocytochemical localization of the GABA transporter in rat brain. J Neurosci 10:1319–1330
Roepstroff A, Lamvert JDC (1994) Factors contributing to the decay of the stimulus-evoked IPSCs in rat hippocampal CA1 neurons. J Neurophysiol 72:2911–2926
Sabau A, Frahm C, Pfeiffer M, Breustedt J-M, Piechotta A, Numberger M, Engel D, Heinemann U, Draguhn A (1999) Age-dependence of the anticonvulsant effects of the GABA uptake inhibitor tiagabine in vitro. Eur J Pharmacol 383:259–266
Saňudo-Peňa MC, Walker JM (1997) Role of the subthalamic nucleus on cannabinoid actions in the substantia nigra of the rat. J Neurophysiol 77:1635–1638
Saňudo-Peňa MC, Walker JM (1998) Effect of intrapallidal cannabinoids on rotational behavior in rats: interactions with the dopaminergic system. Synapse 28:27–32
Schachter SC (2001) Pharmacology and clinical experience with tiagabine. Expert Opin Pharmacother 2:179–187
Smith SE, Parvez NS, Chapman AG, Meldrum BS (1995) The gamma-aminobutyric acid uptake inhibitor, tiagabine, is anticonvulsant in two animal models of reflex epilepsy. Eur J Pharmacol 273:259–265
Suzdak PD, Foged C, Andersen KE (1994) Quantitative autoradiographic characterization of the binding of [3H]tiagabine (NNC 05-328) to the GABA uptake carrier. Brain Res 647:231–241
Thompson SM, Gähwiler BH (1992) Effects of the GABA uptake inhibitor tiagabine on inhibitory synaptic potentials in rat hippocampal slice cultures. J Neurophysiol 67:1698–1701
Vergnes M, Boehrer A, Simler S, Bernasconi R, Marescaux C (1977) Opposite effects of GABAB receptor antagonists on absences and convulsive seizures. Eur J Pharmacol 332:245–255
Yamaguchi K, Nabeshima T, Kameyama T (1986) Role of dopaminergic and GABAergic mechanisms in discrete brain areas in phencyclidine-induced locomotor stimulation and turning behavior. J Pharmacobiodyn 9:975–986
Yasumi M, Sato K, Shimada S, Nishimura M, Tohyama M (1997) Regional distribution of GABA transporter 1(GAT1) mRNA in the rat brain: Comparison with glutamic acid decarboxylase67 (GAD67) mRNA localization. Mol Brain Res 44:205–218
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This work was supported by a grant awarded to W.H. Yung by the Research Grants Council of Hong Kong (CUHK 4080/00M).
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Chen, L., Yung, WH. Effects of the GABA-uptake inhibitor tiagabine in rat globus pallidus. Exp Brain Res 152, 263–269 (2003). https://doi.org/10.1007/s00221-003-1549-7
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DOI: https://doi.org/10.1007/s00221-003-1549-7