Seizures induced by penicillin microinjections in the mesencephalic tegmentum

Citation
F. Jimenez et al., Seizures induced by penicillin microinjections in the mesencephalic tegmentum, EPILEPSY R, 38(1), 2000, pp. 33-44
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurology,"Neurosciences & Behavoir
Journal title
EPILEPSY RESEARCH
ISSN journal
0920-1211 → ACNP
Volume
38
Issue
1
Year of publication
2000
Pages
33 - 44
Database
ISI
SICI code
0920-1211(200001)38:1<33:SIBPMI>2.0.ZU;2-3
Abstract
The location and extension of a convulsive area in the brain stem in cats w as determined through penicillin microinjections (0.5-1.0 mu l) of a concen trated sodium penicillin solution (500 IU/mu l), stereotactically oriented to multiple structures, in fully awake animals, partially restrained throug h a rod fixation system that avoided pain, allowed the observation of clini cal seizures and simultaneous recording of EEG, EMG and multiple unit activ ity (MUA) from the injected site and the motor cortex (Cx). Clinical and EE G seizure patterns in relation to the injected sites and penicillin doses w ere studied in another group of animals using doses from 12.5 IU/0.1 mu l t o 125 IU/1.0 mu l. The time relationship between muscular clonus, EEG spike s and MUA at the injected site and Cx were analyzed. The only area in which penicillin induced seizures was the mesencephalic tegmentum (MT). The amou nt of penicillin but not the stereotactic coordinates determined the seizur e type. MT EEC and MUA paroxysms anticipated clinical seizure and Cx EEG sp ikes. When Cx EEG appeared, they were accompanied by an increase in MUA beg inning in the Cx and EMG, followed by significant increase in MT MUA. The s equence of events suggest that MT seizure activity propagates via alternati ve pathways not involving direct reticulospinal or pyramidal tract pathways . (C) 2000 Elsevier Science B.V. All rights reserved.