Document Detail

Seizures induced by penicillin microinjections in the mesencephalic tegmentum.
MedLine Citation:
PMID:  10604604     Owner:  NLM     Status:  MEDLINE    
The location and extension of a convulsive area in the brain stem in cats was determined through penicillin microinjections (0.5-1.0 microl) of a concentrated sodium penicillin solution (500 IU/microl), stereotactically oriented to multiple structures, in fully awake animals, partially restrained through a rod fixation system that avoided pain, allowed the observation of clinical seizures and simultaneous recording of EEG, EMG and multiple unit activity (MUA) from the injected site and the motor cortex (Cx). Clinical and EEG seizure patterns in relation to the injected sites and penicillin doses were studied in another group of animals using doses from 12.5 IU/0.1 microl to 125 IU/1.0 microl. The time relationship between muscular clonus, EEG spikes and MUA at the injected site and Cx were analyzed. The only area in which penicillin induced seizures was the mesencephalic tegmentum (MT). The amount of penicillin but not the stereotactic coordinates determined the seizure type. MT EEG and MUA paroxysms anticipated clinical seizure and Cx EEG spikes. When Cx EEG appeared, they were accompanied by an increase in MUA beginning in the Cx and EMG, followed by significant increase in MT MUA. The sequence of events suggest that MT seizure activity propagates via alternative pathways not involving direct reticulospinal or pyramidal tract pathways.
F Jimenez; F Velasco; J Carrillo-Ruiz; F E Villanueva; M Velasco; H Ponce
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Epilepsy research     Volume:  38     ISSN:  0920-1211     ISO Abbreviation:  Epilepsy Res.     Publication Date:  2000 Jan 
Date Detail:
Created Date:  2000-01-24     Completed Date:  2000-01-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8703089     Medline TA:  Epilepsy Res     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  33-44     Citation Subset:  IM    
Unit of Neurology, General Hospital and Children's Hospital SS and Medical Research Department, National Medical Center IMSS, Mexico, Mexico.
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MeSH Terms
Dose-Response Relationship, Drug
Electroencephalography / drug effects
Electromyography / drug effects
Hydrogen-Ion Concentration
Penicillins / administration & dosage,  toxicity*
Reticular Formation / physiology
Seizures / chemically induced*,  physiopathology
Stereotaxic Techniques
Tegmentum Mesencephali / physiology*
Reg. No./Substance:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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