Convulsant action of pentetrazol in rats with selective lesions of the hippocampal pyramidal cells with intracerebroventricular kainic acid.

Rats were injected uni- or bilaterally with intracerebroventricular kainic acid (0.1 micrograms per one ventricle in a volume of 5 microliters) and the animals were subsequently challenged with penetetrazol (PTZ) on the 21st day after the administration of the neurotoxin. PTZ was given either subcutaneously in a single dose of 70 mg/kg or intraperitoneally, one injection every 48 hours for a total of 15 trials, in doses of 20 mg/kg to induce kindled seizures. It was found that kainic acid-lesioned animals (especially those injected bilaterally) were more sensitive to the convulsant action of PTZ both in acute and kindled convulsions. The disruption of the hippocampal pyramidal projection to the septum may be responsible for these effects.