Blockage of Cortical Spreading Depression by Picrotoxin Foci of Paroxysmal Activity
- 1 March 1975
- Vol. 16 (1) , 111-118
- https://doi.org/10.1111/j.1528-1157.1975.tb04727.x
Abstract
1 per cent Picrotoxin placed on cortex of rat caused paroxysmal ECoG discharges with concomitant increase in [Ke"] from 3 to 6.7 mM with oscillations corresponding to ictal (maximum) and interictal (minimum) spiking. Invasion of the epileptogenic focus by spreading depression was blocked when the amplitude of oscillations of [Ke+] reached 2.6 mM. Epileptogenic activity induced by topical 10 per cent pentazol caused a less marked increase in [Ke+] (4.6 mM) and did not prevent depression from invading the focal area, but did diminish [Ke+] from the normal of 60 to 70 mM to 39 mM. It is concluded that seizure-induced depolarization of neural elements in deep cortical layers, though inadequate to trigger spreading depression, does prevent it from spreading, in part by activating the sodium pump.Keywords
This publication has 31 references indexed in Scilit:
- Strychnine- and Pentylenetetrazol-Induced Changes of Excitability in Aplysia NeuronsScience, 1973
- Measurement of extracellular potassium activity in cat cortexBrain Research, 1973
- Extracellular potassium concentration changes during propagated seizures in neocortexExperimental Neurology, 1973
- Potassium-selective microelectrodes used for measuring the extracellular brain potassium during spreading depression and anoxic depolarization in ratsBrain Research, 1972
- Unidentified neuroglia potentials during propagated seizures in neocortexExperimental Neurology, 1971
- Analysis of vapor-phase pyrolysis products of the four trimethylpentane isomersAnalytical Chemistry, 1971
- Potassium accumulation in interstitial space during epileptiform seizuresExperimental Neurology, 1970
- Penicillin as Epileptogenic Agent: Its Effect on an Isolated NeuronScience, 1970
- The Ferrier Lecture - Neuroglial cells: physiological properties and a potassium mediated effect of neuronal activity on the glial membrane potentialProceedings of the Royal Society of London. B. Biological Sciences, 1967
- Modification of Focal Cortical Epileptogenic Discharge by Afferent InfluencesEpilepsia, 1966