{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,4]],"date-time":"2026-10-04T21:16:19Z","timestamp":1791148579091,"version":"4.1.0"},"reference-count":53,"publisher":"American Physiological Society","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Neurophysiology"],"published-print":{"date-parts":[[1998,1,1]]},"abstract":"<jats:p>Lopantsev, Valeri and Massimo Avoli. Participation of GABA<jats:sub>A<\/jats:sub>-mediated inhibition in ictallike discharges in the rat entorhinal cortex. J. Neurophysiol. 79: 352\u2013360, 1998. The spontaneous, synchronous activity induced by 4-aminopyridine (4AP, 50 \u03bcM) in the adult rat entorhinal cortex was analyzed with simultaneous field potential and intracellular recordings in an in vitro slice preparation. Four-AP induced isolated negative-going field potentials (interval of occurrence = 27.6 \u00b1 9.9 (SD) s; n = 27 slices) that corresponded to intracellular long-lasting depolarizations (LLDs), and ictallike epileptiform discharges (interval of occurrence = 10.4\u2009\u00b1 5.7 min; n = 27 slices) that were initiated by the negative field potentials. LLDs recorded with K-acetate\u2013filled microelectrodes triggered few action potentials of variable amplitude and had a duration of 1.7 \u00b1 0.8 s ( n = 26 neurons), a peak amplitude of 11.8 \u00b1 5.0 mV ( n = 26 neurons) and a reversal potential of \u221266.2\u2009\u00b1 3.9 mV ( n = 17 neurons). The ictal discharges studied with K-acetate microelectrodes consisted of prolonged depolarizations (duration = 72.9 \u00b1 44.3 s; peak amplitude = 29.2 \u00b1 11.4 mV; n\u2009= 25 neurons) with action-potential firing during both the tonic and the clonic phase. These depolarizations had a reversal potential of \u221245.3 \u00b1 3.8 mV ( n = 4 neurons). Intracellular Cl<jats:sup>\u2212<\/jats:sup>diffusion from KCl-filled microelectrodes made both LLDs and ictal depolarizations increase in amplitude (30.5 \u00b1 8.2 mV, n = 8 and 41.8 \u00b1 9.8 mV, n = 6 neurons, respectively). LLDs recorded with KCl and 2-(trimethyl-amino) N-(2,6-dimethylphenyl)-acetamide (QX-314) microelectrodesreached an amplitude of 36.3 \u00b1 5.2 mV, lasted 12.5 \u00b1 6.5 s, and had a reversal potential of \u221231.3 \u00b1 2.5 mV ( n = 4 neurons); under these recording procedures the ictal discharge amplitude was 41.5\u2009\u00b1 5.0 mV and the reversal potential \u221224.0 \u00b1 7.0 mV ( n = 4 neurons). The N-methyl-d-aspartate (NMDA) receptor antagonist 3,3-(2-carboxy-piperazine-4-yl)-pro-pyl-l-phosphonate (10 \u03bcM, n\u2009= 5 neurons) alone or concomitant with the nonNMDA receptor antagonist 6-cyano-7-nitro-quinoxaline-2,3-dione (10 \u03bcM, n = 4 neurons) abolished ictal discharges, without influencing LLDs. LLDs were blocked by the \u03b3-aminobutyric acid-A (GABA<jats:sub>A<\/jats:sub>) receptor antagonist bicuculline methiodide (BMI, 10 \u03bcM, n = 6 neurons) or the \u03bc-opioid receptor agonist (d-Ala2-N-Me-Phe, Gly-ol) enkephalin (DAGO, 10 \u03bcM, n = 2 neurons). Application of BMI ( n\u2009= 4 neurons) or DAGO ( n = 2 neurons) to control the medium abolished LLDs and ictal discharges but disclosed a novel type of epileptiform depolarization that lasted 3.5 \u00b1 1.2 s and occurred every 5.2 \u00b1 2.6 s ( n = 6 neurons). Our data indicate that 4AP induces in the rat entorhinal cortex a synchronous, GABA-mediated potential that is instrumental in initiating NMDA-dependent, ictal discharges. Moreover we present evidence for an active role played by GABA<jats:sub>A<\/jats:sub>-mediated potentials in the maintenance and termination of these prolonged epileptiform events.<\/jats:p>","DOI":"10.1152\/jn.1998.79.1.352","type":"journal-article","created":{"date-parts":[[2017,12,25]],"date-time":"2017-12-25T07:16:33Z","timestamp":1514186193000},"page":"352-360","source":"Crossref","is-referenced-by-count":115,"title":["Participation of GABA<sub>A<\/sub>-Mediated Inhibition in Ictallike Discharges in the Rat Entorhinal Cortex"],"prefix":"10.1152","volume":"79","author":[{"given":"Valeri","family":"Lopantsev","sequence":"first","affiliation":[{"name":"Research Group on Cell Biology of Excitable Tissue, Montreal Neurological Institute; and Department of Neurology and Neurosurgery and Department of Physiology, McGill University, Montreal, Quebec H3A 2B4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Massimo","family":"Avoli","sequence":"additional","affiliation":[{"name":"Research Group on Cell Biology of Excitable Tissue, Montreal Neurological Institute; and Department of Neurology and Neurosurgery and Department of Physiology, McGill University, Montreal, Quebec H3A 2B4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"24","reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1982.sp014256"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.16-12-03912.1996"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1995.73.2.468"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1996.sp021416"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1993.70.3.1018"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(94)90799-4"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1995.73.4.1462"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1016\/0306-4522(94)90426-X"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1139\/y79-218"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1993.sp019874"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1989.62.5.1149"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1111\/j.1460-9568.1995.tb01150.x"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1038\/378075a0"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1996.75.6.2496"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1038\/310685a0"},{"key":"B16","doi-asserted-by":"crossref","first-page":"476","DOI":"10.1016\/S0022-3565(25)32969-1","volume":"220","author":"Connors B. W.","year":"1982","journal-title":"J. Pharmacol. Exp. Ther."},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1995.sp020697"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.3171\/jns.1992.77.2.0185"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1982.48.6.1321"},{"key":"B20","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1002\/hipo.1993.4500030712","volume":"3","author":"Heinemann U.","year":"1993","journal-title":"Hippocampus"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(96)12496-4"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1126\/science.7444469"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(87)90000-0"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1002\/hipo.450040317"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1988.59.5.1476"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1016\/0301-0082(94)90049-3"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1987.57.1.325"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1002\/cne.902710204"},{"key":"B30","first-page":"981","volume":"21","author":"Lopantsev V.","year":"1995","journal-title":"Soc. Neurosci. Abstr."},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(96)12656-2"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.1152\/physrev.1990.70.2.453"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1985.53.2.557"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1996.76.2.1036"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1126\/science.1654594"},{"key":"B36","doi-asserted-by":"publisher","DOI":"10.1038\/306371a0"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1987.57.3.869"},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1990.64.1.46"},{"key":"B39","doi-asserted-by":"publisher","DOI":"10.1016\/0306-4522(95)00534-X"},{"key":"B40","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.12-05-01867.1992"},{"key":"B41","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1991.65.4.771"},{"key":"B42","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.12-01-00104.1992"},{"key":"B43","doi-asserted-by":"publisher","DOI":"10.3171\/jns.1989.70.5.0667"},{"key":"B44","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1987.57.6.1911"},{"key":"B45","doi-asserted-by":"publisher","DOI":"10.1016\/0006-8993(80)90119-5"},{"key":"B46","doi-asserted-by":"publisher","DOI":"10.1111\/j.1528-1157.1994.tb02502.x"},{"key":"B47","doi-asserted-by":"publisher","DOI":"10.1126\/science.7638623"},{"key":"B48","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1994.sp020259"},{"key":"B49","doi-asserted-by":"publisher","DOI":"10.1111\/j.1528-1157.1996.tb00042.x"},{"key":"B50","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1988.59.1.259"},{"key":"B51","doi-asserted-by":"publisher","DOI":"10.1038\/373612a0"},{"key":"B52","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1995.sp020848"},{"key":"B53","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1002\/hipo.1993.4500030707","volume":"3","author":"Witter M. P.","year":"1993","journal-title":"Hippocampus"},{"key":"B54","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1982.48.4.938"}],"container-title":["Journal of Neurophysiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/jn.1998.79.1.352","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,29]],"date-time":"2025-06-29T05:45:09Z","timestamp":1751175909000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/jn.1998.79.1.352"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1998,1,1]]},"references-count":53,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1998,1,1]]}},"alternative-id":["10.1152\/jn.1998.79.1.352"],"URL":"https:\/\/doi.org\/10.1152\/jn.1998.79.1.352","relation":{},"ISSN":["0022-3077","1522-1598"],"issn-type":[{"value":"0022-3077","type":"print"},{"value":"1522-1598","type":"electronic"}],"subject":[],"published":{"date-parts":[[1998,1,1]]}}}