title: In vitro ictogenesis and parahippocampal networks in a rodent model of temporal lobe epilepsy.
abstract: Temporal lobe epilepsy (TLE) is a chronic epileptic disorder involving the hippocampal formation. Details on the interactions between the hippocampus proper and parahippocampal networks during ictogenesis remain, however, unclear. In addition, recent findings have shown that epileptic limbic networks maintained in vitro are paradoxically less responsive than non-epileptic control (NEC) tissue to application of the convulsant drug 4-aminopyridine (4AP). Field potential recordings allowed us to establish here the effects of 4AP in brain slices obtained from NEC and pilocarpine-treated epileptic rats; these slices included the hippocampus and parahippocampal areas such as entorhinal and perirhinal cortices and the amygdala. First, we found that both types of tissue generate epileptiform discharges with similar electrographic characteristics. Further investigation showed that generation of robust ictal-like discharges in the epileptic rat tissue is (i) favored by decreased hippocampal output (ii) reinforced by EC-subiculum interactions and (iii) predominantly driven by amygdala networks. We propose that a functional switch to alternative synaptic routes may promote network hyperexcitability in the epileptic limbic system.
authors.affiliation: Montreal Neurological Institute and Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Panuccio
authors.forename: M
authors.initials: M
authors.lastname: D'Antuono
authors.forename: P
authors.initials: P
authors.lastname: de Guzman
authors.forename: L
authors.initials: L
authors.lastname: De Lannoy
authors.forename: G
authors.initials: G
authors.lastname: Biagini
authors.forename: M
authors.initials: M
authors.lastname: Avoli
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000679:Amygdala / Q000187:drug effects / Q000503:physiopathology*; D000818:Animals; D004195:Disease Models, Animal; D004594:Electrophysiology; D004833:Epilepsy, Temporal Lobe / Q000139:chemically induced / Q000503:physiopathology*; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology*; D008297:Male; D009415:Nerve Net / Q000187:drug effects / Q000503:physiopathology*; D020534:Parahippocampal Gyrus / Q000187:drug effects / Q000503:physiopathology*; D010862:Pilocarpine; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010862:Pilocarpine; D015761:4-Aminopyridine
references.citation: Science. 2003 Jul 25;301(5632):463; author reply 463
references.pmid: 12881553
references.citation: Brain Res Bull. 2006 Dec 11;71(1-3):127-38
references.pmid: 17113938
references.citation: Hippocampus. 2006;16(10):843-60
references.pmid: 16897722
references.citation: Neuroscience. 2004;126(2):485-501
references.pmid: 15207366
references.citation: J Neurosci. 2006 Nov 15;26(46):11850-6
references.pmid: 17108158
references.citation: Prog Neurobiol. 1989;33(3):161-253
references.pmid: 2682783
references.citation: Electroencephalogr Clin Neurophysiol. 1972 Mar;32(3):281-94
references.pmid: 4110397
references.citation: J Neurosci. 1996 Jun 15;16(12):3912-24
references.pmid: 8656285
references.citation: J Neurophysiol. 2000 Mar;83(3):1115-24
references.pmid: 10712442
references.citation: Ann N Y Acad Sci. 2000 Jun;911:369-91
references.pmid: 10911886
references.citation: J Neurophysiol. 2001 Dec;86(6):2887-95
references.pmid: 11731545
references.citation: Ann Neurol. 1989 Sep;26(3):321-30
references.pmid: 2508534
references.citation: Epilepsia. 2000;41 Suppl 6:S90-5
references.pmid: 10999527
references.citation: Neurosci Lett. 1994 Jun 20;174(2):160-4
references.pmid: 7970173
references.citation: J Neurosci. 1997 Dec 1;17(23):9308-14
references.pmid: 9364076
references.citation: Epilepsy Res. 1998 Sep;32(1-2):233-53
references.pmid: 9761324
references.citation: Adv Neurol. 1999;79:743-61
references.pmid: 10514861
references.citation: Epilepsy Res. 1997 Jan;26(2):315-27
references.pmid: 9095393
references.citation: J Neurophysiol. 2006 Apr;95(4):2143-54
references.pmid: 16381802
references.citation: Neurosci Lett. 1995 Dec 1;201(1):87-91
references.pmid: 8830321
references.citation: Ann Neurol. 1998 Dec;44(6):923-34
references.pmid: 9851437
references.citation: Epilepsia. 1991 Nov-Dec;32(6):778-82
references.pmid: 1743148
references.citation: Science. 1987 Jan 2;235(4784):73-6
references.pmid: 2879352
references.citation: J Physiol. 2003 May 15;549(Pt 1):219-30
references.pmid: 12665605
references.citation: J Neurophysiol. 2002 Jan;87(1):634-9
references.pmid: 11784779
references.citation: J Comp Neurol. 1999 Jun 14;408(4):449-60
references.pmid: 10340497
references.citation: N Engl J Med. 2001 Aug 2;345(5):311-8
references.pmid: 11484687
references.citation: Neuroscience. 2004;123(4):875-86
references.pmid: 14751281
references.citation: J Neurosci Methods. 2008 Jul 30;172(2):143-57
references.pmid: 18550176
references.citation: J Neurosci. 2003 Sep 17;23(24):8471-9
references.pmid: 13679415
references.citation: J Neurosci. 1988 Jul;8(7):2213-26
references.pmid: 3249220
references.citation: Science. 2004 Jul 23;305(5683):532-5
references.pmid: 15273397
references.citation: Exp Brain Res. 1991;87(3):581-96
references.pmid: 1783028
references.citation: Eur J Neurosci. 2001 Apr;13(7):1371-9
references.pmid: 11298797
references.citation: J Comp Neurol. 2005 Mar 21;483(4):476-88
references.pmid: 15700275
references.citation: Science. 2002 Nov 15;298(5597):1418-21
references.pmid: 12434059
references.citation: Neuroscience. 2009 Sep 29;163(1):415-29
references.pmid: 19540312
references.citation: Neurobiol Dis. 2008 Feb;29(2):186-200
references.pmid: 17942314
references.citation: Eur J Neurosci. 1998 Mar;10(3):1011-8
references.pmid: 9753168
references.citation: J Comp Neurol. 2000 Oct 23;426(3):441-67
references.pmid: 10992249
references.citation: Eur J Neurosci. 2001 Feb;13(4):657-69
references.pmid: 11207801
references.citation: Eur J Neurosci. 1996 Dec;8(12):2711-25
references.pmid: 8996821
references.citation: Prog Neurobiol. 2002 Oct;68(3):167-207
references.pmid: 12450487
references.citation: J Neurosci. 2006 Jan 11;26(2):406-10
references.pmid: 16407536
references.citation: Epilepsia. 2005;46 Suppl 5:17-21
references.pmid: 15987248
references.citation: Nat Med. 1998 Oct;4(10):1166-72
references.pmid: 9771750
references.citation: Eur J Neurosci. 2003 Nov;18(10):2779-91
references.pmid: 14656327
references.citation: Brain. 2008 Jun;131(Pt 6):1516-27
references.pmid: 18504292
references.citation: J Physiol. 2005 Aug 1;566(Pt 3):885-900
references.pmid: 15932889
references.citation: Neurobiol Dis. 2005 Aug;19(3):451-60
references.pmid: 16023587
references.citation: Epilepsia. 2009 Jan;50 Suppl 1:53-8
references.pmid: 19125849
references.citation: Brain Res. 2000 Mar 17;859(1):15-20
references.pmid: 10720610
references.citation: Exp Neurol. 2004 Jun;187(2):367-79
references.pmid: 15144863
references.citation: Neurosci Res. 2002 Sep;44(1):91-100
references.pmid: 12204297
references.citation: J Neurophysiol. 1991 Sep;66(3):999-1009
references.pmid: 1684384
references.citation: Epilepsy Res. 1993 Dec;16(3):223-33
references.pmid: 8119273
references.citation: J Neurosci. 2006 Apr 26;26(17):4613-23
references.pmid: 16641241
references.citation: Neuromolecular Med. 2005;7(4):325-42
references.pmid: 16391389
references.citation: Epilepsia. 2002 Apr;43(4):350-7
references.pmid: 11952764
references.citation: J Neurosci. 2007 Sep 12;27(37):9866-73
references.pmid: 17855601
references.citation: J Physiol. 2008 Apr 1;586(7):1867-83
references.pmid: 18238812
references.citation: Neuroscience. 2003;120(1):75-84
references.pmid: 12849742
references.citation: Epilepsy Res. 2008 Feb;78(2-3):102-16
references.pmid: 18226499
references.citation: Trends Neurosci. 2005 Jun;28(6):334-40
references.pmid: 15927690
references.citation: Brain Res. 1976 Dec 24;118(3):475-8
references.pmid: 1009431
references.citation: J Neuropathol Exp Neurol. 2008 Jul;67(7):687-701
references.pmid: 18596544