RETURNAmygdaloid Kindling in Weanling Rats and Persistence of Seizure Susceptibility into Adulthood
Ryuzo Kawahara, Kazuyoshi Matsuda, Hisayoshi Takeshita and Hidebumi Hazama
Department of Neuro-Psychiatry, Faculty of Medicine, Tottori University, Yonago 683, Japan
The experiments were carried out to examine the characteristics of kindling development after maturation in rats that were kindled in infancy. Experiment I: Ten 3-week-old male Wistar rats (the 3-week-old group) and ten 10-week-old rats (the 10-week-old group) were subjected to right amygdaloid kindling at 2-hourly interval, 5 times a day staring 6 days after the operation. Experiment II: This experiment used 9 rats that had been kindled at the age of 3 weeks and rekindled after maturation (K group), and 10 rats that had been given shame operation at the age of 3 weeks and kindled after maturation (non-K group). The results were as follows: i) The number of stimulations necessary at stage C0-2 was significantly lower in the 3-week-old group than in the 10-week-old group, although both groups were almost equal at stage C3-4. ii) The rats in the K group needed a significantly lower number of kindling stimulation than those in the non-K group. This result was attributed to the significantly lower number of stimulation needed at stage C0-2 in the K group. In conclusion, excitability in the limbic system was considered to be high in the 3-week-old group, and the epileptogenicity acquired at 3 weeks was maintained as strong excitability in the limbic system even after maturation.
Key words: epileptogenicity; kindling; maturation; rats