GABAergic mechanisms in epilepsy
- PMID: 11520315
- DOI: 10.1046/j.1528-1157.2001.042suppl.3008.x
GABAergic mechanisms in epilepsy
Abstract
gamma-Aminobutyric acid (GABA), the principal inhibitory neurotransmitter in the cerebral cortex, maintains the inhibitory tone that counterbalances neuronal excitation. When this balance is perturbed, seizures may ensue. GABA is formed within GABAergic axon terminals and released into the synapse, where it acts at one of two types of receptor: GABAA, which controls chloride entry into the cell, and GABAB, which increases potassium conductance, decreases calcium entry, and inhibits the presynaptic release of other transmitters. GABAA-receptor binding influences the early portion of the GABA-mediated inhibitory postsynaptic potential, whereas GABAB binding influences the late portion. GABA is rapidly removed by uptake into both glia and presynaptic nerve terminals and then catabolized by GABA transaminase. Experimental and clinical study evidence indicates that GABA has an important role in the mechanism and treatment of epilepsy: (a) Abnormalities of GABAergic function have been observed in genetic and acquired animal models of epilepsy; (b) Reductions of GABA-mediated inhibition, activity of glutamate decarboxylase, binding to GABAA and benzodiazepine sites, GABA in cerebrospinal fluid and brain tissue, and GABA detected during microdialysis studies have been reported in studies of human epileptic brain tissue; (c) GABA agonists suppress seizures, and GABA antagonists produce seizures; (d) Drugs that inhibit GABA synthesis cause seizures; and (e) Benzodiazepines and barbiturates work by enhancing GABA-mediated inhibition. Finally, drugs that increase synaptic GABA are potent anticonvulsants. Two recently developed antiepileptic drugs (AEDs), vigabatrin (VGB) and tiagabine (TGB), are examples of such agents. However, their mechanisms of action are quite different (VGB is an irreversible suicide inhibitor of GABA transaminase, whereas TGB blocks GABA reuptake into neurons and glia), which may account for observed differences in drug side-effect profile.
Similar articles
-
[Gabaergic hypothesis of epilepsy and clinical experience: controversial actions of the new generation gabamimetic antiepileptic drugs].Neurol Neurochir Pol. 2000;34 Suppl 8:9-21. Neurol Neurochir Pol. 2000. PMID: 11780594 Review. Polish.
-
The new generation of GABA enhancers. Potential in the treatment of epilepsy.CNS Drugs. 2001;15(5):339-50. doi: 10.2165/00023210-200115050-00001. CNS Drugs. 2001. PMID: 11475940 Review.
-
Neurotransmission in epilepsy.Epilepsia. 1995;36 Suppl 1:S30-5. doi: 10.1111/j.1528-1157.1995.tb01649.x. Epilepsia. 1995. PMID: 23057108 Review.
-
[Implications of GABAergic synapses in neuropsychiatry].J Pharmacol. 1985;16 Suppl 2:5-27. J Pharmacol. 1985. PMID: 2867252 Review. French.
-
Update on the mechanism of action of antiepileptic drugs.Epilepsia. 1996;37 Suppl 6:S4-11. doi: 10.1111/j.1528-1157.1996.tb06038.x. Epilepsia. 1996. PMID: 8941036 Review.
Cited by
-
From bench to bedside: The mGluR5 system in people with and without Autism Spectrum Disorder and animal model systems.Transl Psychiatry. 2022 Sep 20;12(1):395. doi: 10.1038/s41398-022-02143-1. Transl Psychiatry. 2022. PMID: 36127322 Free PMC article.
-
Synedrella nodiflora Extract Depresses Excitatory Synaptic Transmission and Chemically-Induced In Vitro Seizures in the Rat Hippocampus.Front Pharmacol. 2021 Mar 8;12:610025. doi: 10.3389/fphar.2021.610025. eCollection 2021. Front Pharmacol. 2021. PMID: 33762938 Free PMC article.
-
Multipronged Attack of Stem Cell Therapy in Treating the Neurological and Neuropsychiatric Symptoms of Epilepsy.Front Pharmacol. 2021 Mar 17;12:596287. doi: 10.3389/fphar.2021.596287. eCollection 2021. Front Pharmacol. 2021. PMID: 33815100 Free PMC article. Review.
-
Cellular mechanisms underlying acquired epilepsy: the calcium hypothesis of the induction and maintainance of epilepsy.Pharmacol Ther. 2005 Mar;105(3):229-66. doi: 10.1016/j.pharmthera.2004.10.004. Epub 2004 Dec 9. Pharmacol Ther. 2005. Corrected and republished in: Pharmacol Ther. 2006 Jul;111(1):288-325. doi: 10.1016/j.pharmthera.2004.10.015 PMID: 15737406 Free PMC article. Corrected and republished. Review.
-
NF-kappaB/Rel regulates inhibitory and excitatory neuronal function and synaptic plasticity.Mol Cell Biol. 2006 Oct;26(19):7283-98. doi: 10.1128/MCB.00510-06. Mol Cell Biol. 2006. PMID: 16980629 Free PMC article.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical