Amygdala kindling in juvenile rats following neonatal administration of 6-hydroxydopamine.

The role of catecholamines in mediating the acquisition of amygdala-kindled seizures was investigated in juvenile rats administered intracisternal injections of 6-hydroxydopamine (6-OHDA) on postnatal days 1 and 2. Amygdala kindling was initiated on day 28, using stimulations delivered each hour through two consecutive stage V seizures. The 6-OHDA treatment resulted in a 53% increase in the overall rate of kindling in juvenile rats. This acceleration was confined primarily to the early phases of kindling in that the 6-OHDA-treated rats skipped the early kindling stages, and the later stages of kindling were unaffected. These findings support evidence from adult rats that catecholamines play a role in initially limiting the spread of seizure activity during kindled seizure acquisition; however, when the seizures have begun to generalize, the ability of catecholaminergic systems to inhibit seizure spread diminishes.