The kindled seizure: production of and modification by dieldrin in rats.

In the rat dieldrin can evoke a progressive increase in the severity of convulsive responses (kindling) during repetitive exposures that cannot be attributed to simple accumulation of dieldrin in the brain. It can also replace pentylenetetrazol as a kindling stimulus in previously pentylenetetrazol-kindled rats (cross-kindling). Chronic exposure to dieldrin facilitates kindling produced by daily electrical stimulation of the amygdala. Even single, acute exposure, can facilitate kindling produced by electrical stimulation of the amygdala, 1 to 3 weeks later. We propose that the procedure of kindling is a useful one with which to assess neurotoxicity. Agents affecting kindling in laboratory animals are of particular concern to those individuals in a population with demonstrable seizure susceptibility, those predisposed to convulsive disorders and others vulnerable to increased levels of CNS excitability.