—Dogs were given repeated doses of pentylenetetrazol to maintain a condition of status epilepticus for periods of 30–40 min. Analyses of cerebral tissue frozen in situ showed significant increases in alanine, arginine, γ-aminobutyric acid, glycine, histidine, leucine, lysine, phenylalanine, serine, tyrosine, and valine. Decreases occurred in the glutamic and aspartic acid levels. Other measured amino compounds were unchanged. Ammonia was increased, but not more than occurs in seizures of brief duration. A large decrease was noted in the ganglioside fraction, and a decrease also in a fraction containing the lecithins and sphingomyelins. The cephalin, cerebroside–sulphatide, and cholesterol fractions were not affected.

Similar repetitive seizures induced by bemegride and continuing for shorter periods (5–9 min) brought about less extensive changes. Glutamic acid was increased, in contrast to the pentylenetetrazol effect, and the apparent decrease in aspartic acid was not statistically significant. Increases were noted in alanine, γ-aminobutyric acid, lysine, and ammonia. The ganglioside and lecithin-sphingomyelin fractions were decreased.