KINDLING OF THE INTERPEDUNCULAR NUCLEUS AND ITS INFLUENCE ON SUBSEQUENT AMYGDALA KINDLING IN RATS

We examined the effect of interpeduncular nucleus (IPN) kindling on su bsequent amygdala (AM) kindling in rats(n = 9). Eleven to 15 daily IPN stimulations at an afterdischarge (AD)-inducing threshold (400-1000 m u A, biphasic sine waves, 1-3 s) produced progressive AD growth (9 of 9 rats) and recruitment of behavioral seizures (7 of 9 rats). The fina l form of the latter was generalized tonic-clonic seizures with or wit hout a limbic seizure component. The latter was associated with ictal involvement of AM and sensorimotor cortex. Subsequent AM kindling resu lted not only in more rapid kindling, but also in tonic seizure associ ated with a protracted loss of postural control (5-20 s) not observed in animals undergoing AM kindling without previous IPN kindling (n = 5 ), These findings indicate that the IPN can be kindled and that subseq uent AM kindling utilizes the proconvulsant neuroplastic changes that have been already established by IPN kindling.