4 Aminopyridine Induced Epileptiform Activity.
- Author:
Byung Joon CHOI
1
;
Kyung Tai WHANG
Author Information
1. Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea. choibj@catholic.ac.kr
- Publication Type:Original Article
- Keywords:
4-aminopyridine;
Experimental epilepsy
- MeSH:
4-Aminopyridine*;
6-Cyano-7-nitroquinoxaline-2,3-dione;
Brain;
Rats, Sprague-Dawley;
Receptors, Glutamate;
Seizures;
Visual Cortex
- From:
Journal of the Korean Child Neurology Society
2005;13(1):63-68
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: The goal of the present study was to investigate the effects of 4-aminopyridine(4-AP) on the excitability of visual cortex, observe the induction of epileptiform activity and define the characteristics of spontaneous activity. METHODS: We divided 19 to 23-day-old Sprague-Dawley rats into 3 groups by the concentration of 4-AP:5(n=10), 50(n=11), and 100(n=12) microM. The slices from their brains were incubated in artificial CSF for 1 hour, and then extracellular recordings were performed. RESULTS: Spontaneous epileptiform activities were observed in 50 and 100 microM 4-AP groups. The latencies of interictal epileptiform activity were 7.8+/-1.1 and 5.8+/-0.9 min, the frequencies 1.8+/-0.2 and 24.1+/-6.6 min-1, the amplitudes 0.7+/-0.1 and 2.8+/-0.5 mV, and the durations 238.0+/-57.8 and 242.2+/-70.0 ms in 50 and 100 microM 4-AP groups respectively. The latencies of ictal epileptiform activity were 21.0+/-9.8 and 6.7+/-2.3 min, the frequencies 116.2+/-46.7 and 193.7+/-26.4/event, the amplitudes 3.1+/-0.8 and 2.8+/-0.9 mV, and the durations 26.9+/-27.6, 35.2+/-12.6 s in 50 and 100 microM 4-AP groups respectively. CONCLUSION: 4-AP showed increased excitability in the visual cortex and induced interictal and ictal spontaneous epileptiform activity. This induction was decreased by D- AP5 or CNQX. Those results suggest that both types of inotropic excitatory amino acid receptors are overactivated and contribute to seizure initiation and propagation.
