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To research the characteristics of ion currents induced by inhibitory and excitatory herbs of oriental medicine, we used nystatin-perforated patch clamp technique under voltage clamp condition in periaqueductal gray neuron dissociated from Sprauge-Dawley rat, 10-15 days old. The results are as follows. 1. Ion current induced by 10mg/m{ell} of Bupleuri Radix was inhibited 59.50{pm}4.29% by 10^{-4}M bicuculline(p>0.01) but inhibition of 10.75{pm}4.77% by 10^{-4}M tubocurarine and 4.75{pm}4.23% by 10^{-4}M verapamil had no statistical significance(p>0.05). So ion current induced by Bupleuri Radix revealed only GABA induced Cl^- current, not acetylcholine and Ca^{2+} current. 2. Ion current induced by 20mg/m{ell} of Coptidis Rhizoma was inhibited 47.20{pm}7.88% by 10^{-4}M bicuculline(p<0.01) but 3.20{pm}2.33% inhibition by 10^{-4}M tubocurarine and 1.00{pm}1.00% inhibition by 10^{-4}M verapamil had no significance(p>0.05). So ion current induced by Coptidis Rhizoma revealed only GABA induced Cl^- current, not acetylcholine and Ca^{2+} current. 3. Ion current induced by 20mg/m{ell} of Ecliptae Herba was inhibited 55.00{pm}4.92% by 10^{-4}M bicuculline (p<0.01), and also inhibited 15.00{pm}4.26% by 10^{-4}M tubocurarine(p<0.05), but inhibition of 6.00{pm}3.03% by 10^{-4}M verapamil had no significance(p>0.05). So ion current induced by Ecliptae Herba showed GABA activated Cl^- current and acetylcholine activated cation current, not Ca^{2+} current 4. Ion current induced by 5mg/m{ell} of Liriopis Tuber was inhibited 15.20{pm}4.57% by 10^{-4}M bicuculline<0.05) and also inhibited 14.00{pm}3.00% by 10^{-4}M tubocurarine(p<0.05), but inhibition of 5.20{pm}4.80% by 10^{-4}M verapamil had no significance(p>0.05). So ion current induced by Liriopis Tuber showed GABA. activated Cl^- current and acetylcholine activated cation current, not Ca^{2+} current. 5. Ion current induced by 5mg/m{ell} of Aconiti Tuber was inhibited 97.00{pm}1.34% by 10^{-4}M bicuculline(p<0.01), 80.00{pm}9.83% by 10^{-4}M tubocurarine(p<0.01), and 24.00{pm}6.18% by 10^{-4}M verapamil(p<0.05). So ion current induced by Aconiti Tuber revealed GABA activated Cl^- current and acetylcholine activated cation current and Ca^{2+} current. 6. Ion current induced by 10mg/m{ell} of Zingiberis Rhizoma was inhibited 33.00{pm}7.43% by 10^{-4} bicuculline(p<0.05), 10.20{pm}1.83% by 10-^{-4}M tubocurarine(p<0.01), and 14.00{pm}2.16% by 10^{-4}M verapamil(p<0.01) So ion current induced by Zingiberis Rhizoma revealed GABA activated Cl^- current and acetylcholine activated cation outtent and Ca^{2+} current. 7. Ion current induced by 10mg/m{ell} of Boshniakiae Herba was inhibited $65.00{pm}13.75% by 10^{-4}M bicuculline(p<0.05), 38.00{pm}9.24% by 10^{-4}M tubocurarine(p<0.05), and 33.25{pm}7.42% by 10^{-4}M verapamiHp<0.05). So ion current induced by Bpshniakiae Herba revealed GABA activated Cl^- current and acetylcholine activated cation current and Ca^{2+} current. These results suggest that a point of difference between inhibitory and excitatory herbs is existence of Ca^{2+} current.
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