QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (25) Citing Articles via Google Scholar Google Scholar Articles by Staak, R. Articles by Pape, H.-C. Search for Related Content PubMed PubMed Citation Articles by Staak, R. Articles by Pape, H.-C. Pubmed/NCBI databases Compound via MeSH Substance via MeSH

 Previous Article  |  Next Article 

The Journal of Neuroscience, February 15, 2001, 21(4):1378-1384

Contribution of GABA_A and GABA_B Receptors to Thalamic Neuronal Activity during Spontaneous Absence Seizures in Rats

Rainer Staak and Hans-Christian Pape

Institute of Physiology, Medical School, Otto-von-Guericke University, 39120 Magdeburg, Germany

The contribution of GABAergic mechanisms in thalamic relay nuclei to spike and wave discharges (SWDs) during spontaneous seizures was assessed using the WAG/Rij strain of rats, an established genetic model of absence epilepsy, in combination with single-unit recordings and microiontophoretic techniques in the ventrobasal thalamic complex in vivo. Spontaneous SWDs occurring on the electroencephalogram at 5-9 Hz were associated with burst firing in thalamocortical neurons, which was phase-locked with the spike component. Microiontophoretic application of the GABA_A receptor antagonist bicuculline significantly increased the magnitude of SWD-related firing in all tested cells. Application of the GABA_B receptor antagonist CGP 55845A exerted a statistically insignificant modulatory effect on neuronal activity during spontaneous SWDs but significantly attenuated the bicuculline-evoked aggravation of SWD-related firing. The data indicate that, in thalamocortical neurons, (1) GABA_A receptor-mediated events are recruited with each SWD, (2) SWD-related activity can be evoked with no significant contribution of GABA_B receptors, and (3) blockade of GABA_A receptors potentiates SWD-related activity, presumably through an indirect effect mediated through GABA_B receptors. These results vote against a predominant or even exclusive contribution of GABA_B receptors to spontaneous SWDs in thalamic relay nuclei in the WAG/Rij strain, but rather point to a critical role of GABA_A receptor activation. This conclusion is in support of the view that the two subtypes of GABA receptors play a differential role in fast (5-10 Hz) and slow (3 Hz) spike-wave paroxysms observed during absence seizures.

Key words: absence epilepsy; spike and wave discharges; thalamus; GABA_A; GABA_B; microiontophoresis; GAERS; WAG/Rij

---

Copyright © 2001 Society for Neuroscience  0270-6474/01/2141378-07$05.00/0

This article has been cited by other articles:

				F.-Z. Shaw 7-12 Hz High-Voltage Rhythmic Spike Discharges in Rats Evaluated by Antiepileptic Drugs and Flicker Stimulation J Neurophysiol, January 1, 2007; 97(1): 238 - 247. [Abstract] [Full Text] [PDF]

				L. Liu, T. Zheng, M. J. Morris, C. Wallengren, A. L. Clarke, C. A. Reid, S. Petrou, and T. J. O'Brien The Mechanism of Carbamazepine Aggravation of Absence Seizures J. Pharmacol. Exp. Ther., November 1, 2006; 319(2): 790 - 798. [Abstract] [Full Text] [PDF]

				T. Budde, L. Caputi, T. Kanyshkova, R. Staak, C. Abrahamczik, T. Munsch, and H.-C. Pape Impaired Regulation of Thalamic Pacemaker Channels through an Imbalance of Subunit Expression in Absence Epilepsy J. Neurosci., October 26, 2005; 25(43): 9871 - 9882. [Abstract] [Full Text] [PDF]

				V. S. Sohal and J. R. Huguenard Inhibitory Interconnections Control Burst Pattern and Emergent Network Synchrony in Reticular Thalamus J. Neurosci., October 1, 2003; 23(26): 8978 - 8988. [Abstract] [Full Text] [PDF]

				A. DESTEXHE and T. J. SEJNOWSKI Interactions Between Membrane Conductances Underlying Thalamocortical Slow-Wave Oscillations Physiol Rev, October 1, 2003; 83(4): 1401 - 1453. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help