Chemical kindling induced by microinjection of Coriaria lactone into hippocampus in rabbits
Chen, Q.X.; Xie, Y.G.; Chai, H.X.; Huang, Y.
Hua Xi Yi Ke Da Xue Xue Bao 18(2): 111-114
1987
ISSN/ISBN: 0257-7712 PMID: 3623533 Document Number: 291948
Coriaria lactone (CL) is the active constituent of Loranthus on Coriaria sinica Maxim., a highly effective traditional Chinese medicine in causing convulsion. Since 1979, CL has been used in our studies of the acute epileptic model in rabbits, rats, and tupaias. In this experiment, we have succeeded in creating a chemical kindling by repeated administration of subthreshold dosages of CL in rabbits. This has provided an ideal chronic model of epilepsy for systematic observation of curative effect of antiepileptic drugs and studies of the pathogenesis of epilepsy. Seventeen normal rabbits weighing 2.0-2.5 kg were selected. Thirteen of them received once daily injections through a single stainless steel cannula chronically implanted in the left hippocampus, of 2.mu.l of diluted solution containing 0.22, 0.32, 0.5 or 1 .mu.g of CL. Each of the experimental groups consisted separately of 4, 3, 4, 2 rabbits. The others received injections of normal saline of the same volume as control. Hippocampal EEG and ECoG of all rabbits were recorded by telemetric method and the behavior of them was observed at the same time. The results of the experiment indicated that repeated intrahippocampal injections at subthreshold dosages of CL resulted in kindled seizures. Once the kindling effect of hippocampus was established, it would persist for 34-103 days (Mean: 58 days). Evoked seizures were observed in all fully kindled rabbits, and in addition to evoked seizures spontaneous seizures occurred in two of them.