Bidirectional transfer of intracerebrally administered pentylenetetrazol and electrical kindling

Rats were kindled using electrical stimulation or the infusion of pentylenetetrazol (PTZ) in one amygdala, and subsequently rekindled using infusion of PTZ or electrical stimulation, respectively, in the contralateral amygdala. Control rats received infusions of saline into one amygdala, and were subsequently electrically kindled in the contralateral amygdala. The rats that previously had been kindled using one agent kindled significantly more rapidly and displayed significantly stronger generalized seizures when rekindled using the other agent. The results demonstrate that intracerebrally administered PTZ can effectively kindle seizures, and thus that a peripheral change in response to PTZ is not crucial for seizure development. The results also demonstrate that this form of kindling transfers bidirectionally to electrical kindling.