Strychnine-induced Seizures Research Articles

Voltage clamp study of cat spinal motoneurons during strychnine-induced seizures

Cat spinal motoneurons were examined by the technique of somatic voltage clamp during strychnine-induced spinal seizures. No clear alteration of voltage-dependent ionic currents was required in order for typical strychnine-induced paroxysmal depolarization shifts (PDSs) to develop in contrast to results previously obtained during penicillin-induced spinal seizures. Voltage clamp of evoked and spontaneous PDSs indicates these are generated by a synchronized mixture of excitatory and inhibitory synaptic currents with excitation predominating.

Effect of intraventricular administration of anti-somatostatin gamma-globulin on the lethal dose-50 of strychnine and pentobarbital in rats.

Effects of intraventricular injection of sheep anti-somatostatin gamma-globulin (anti-SSG) on strychnine-induced seizures, strychnine LD50, and pentobarbital LD50 were examined in male rats under light ether anesthesia. Ten microliters of anti-SSG given 2 h earlier significantly decreased the duration of strychnine-induced seizures as compared with that in the control rats pretreated with normal sheep gamma-globulin (NSG). This effect of anti-SSG seemed to be specific, as there was no difference in seizure duration between sheep anti-LHRH gamma-globulin (anti-LHRHG)- and NSG-pretreated rats. Survival rates in anti-SSG-pretreated rats after injection of strychnine and pentobarbital were significantly larger (P less than 0.01 and P less than 0.05, respectively) than those in the control rats receiving NSG. The administration of anti-SSG resulted in 26.7% and 22.9% increases in the LD50 of strychnine and pentobarbital, respectively. These results indicate that endogenous somatostatin in the cerebrospinal fluids and/or the periventricular tissue nodulates the response of the central nervous system to strychnine and pentobarbital in rats.

Pharmacological comparison of R(+), S(−) and racemic thiopentone in mice

The i.p. LD 50's of the enantiomorphs of thiopentone have the following increasing order of lethality R(+), racemate and S(−). Whereas the racemate and the S(−) compound have similar therapeutic indices, the R(+) compound has the highest value. The S(−) isomer is the most potent anesthetic agent, followed by the R(+) and the racemate. In the ability to block pentylenetetrazol- and strychnine-induced seizures, the compounds are ranked in the following order of decreased potency: S(−), racemate and R(+). The differences in potency between antipodes have been related to absolute steric configuration of the molecules. Differences in potency of the stereoisomers have been discussed in relationship to known metabolic conversions of thiopentone and its rapid penetration into body fat depots.

Acute strychnine-induced seizures in cats: a Golgi study.

EpilepsiaVolume 16, Issue 5 p. 791-792 Acute Strychnine-Induced Seizures in Cats:A Golgi Study David S. Knopman, David S. Knopman Department of Neurology, University of Minnesota and St. Paul-Ramsey Hospital, Minneapolis, Minnesota 55455Search for more papers by this author David S. Knopman, David S. Knopman Department of Neurology, University of Minnesota and St. Paul-Ramsey Hospital, Minneapolis, Minnesota 55455Search for more papers by this author First published: December 1975 https://doi.org/10.1111/j.1528-1157.1975.tb04766.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume16, Issue5December 1975Pages 791-792 RelatedInformation

Central nervous system effects of hypothalamic peptides.

Intravenous (i.v.) administration of TRF (1 mg/kg) increases the LD50 of pentobarbital (PB) by 25% while the same dose of somatostatin results in a 30% reduction in PB LD50. A similar increase of PB LD50 by TRF was observed in hypophysectomized rats. Mortality was completely abolished in rats receiving TRF (1 mg/kg) ten minutes after a lethal dose of PB (120 mg/kg). Somatostatin (1 mg/kg) decreases strychnine-induced seizure duration and increases strychnine LD50 by 21% while TRF lowers the strychnine LD50 by 28%. These observations are consistent with central nervous system sites of action for TRF and somatostatin.

Effects of gamma-hydroxybutyrate on chick behaviour, electrocortical activity and crossed extensor reflexes.

1. Convulsant and anticonvulsant effects of gamma-hydroxybutyrate (GHB) have been studied in chicks.2. When administered alone, GHB produced weak myoclonic seizures accompanied by electrocortical synchrony and spikes.3. GHB was found to protect chicks against leptazol- and picrotoxin-induced seizures. A slight potentiation of strychnine-induced seizures was evident.

Pharmacological comparison of R(+), S(−) and racemic secobarbital in mice

Pharmacological tests in mice demonstrated differences in potency between the stereoisomers of secobarbital. The S(−) antipode was a more potent anesthetic than either the R(+) antipode or the racemic mixture. The S(−) isomer was also the most toxic and the R(+) the least toxic. As anticonvulsants both compounds were equipotent against pentylenetetrazol- and strychnine-induced seizures but the S(−) isomer protected the animals for a longer time interval than the R(+) isomer. The results obtained have been discussed upon the basis of the steric configurations of the compounds.

Inhibitory of glycine on spinal neurons in the cat.

Inhibitory of glycine on spinal neurons in the cat.