악안면 통각의 전달 기전에 관한 연구

다국어 초록 (Multilingual Abstract)

Voltage-dependent sodium and calcium currents in small (less than 30㎛) neurons from adult rat trigeminal root ganglia were characterized with a standard whole-cell patch clamp technique. Two types of sodiem current(I_Na) showing different sensitivity to tetrodotoxin(TTX) were recorded, which showed marked differences in their activating and inactivating time courses. The activation and steady-state inactivation kinetics of TTX-resistant I_Na were more depolarized by about +20 and +30 mV, respectively, than those of TTX-sensitive I_Na. Voltage-dependent calcium current(I_Ca) was recorded under the condition that suppressed sodium and potassium currents using 10 mM Ca^2+ as a charge carrier. Depolarizing step pulses from a holding potential of-80mV evoked two distinct inward I_Ca, low-voltage activated(LVA) and high-voltage activated(HVA) I_Ca. LVA I_Ca was first observed at -60∼-50 mV and reached a peak at about -30mV. Amiloride(0.5mM) suppressed near 60％ of the LVA I_Ca, whereas ∼10％ of HVA_ICa was inhibited by the same concentration of the amiloride. LVA I_Ca was far less affected by the presence of external Cd_2+ or the replacement of Ca_2+ by 10 Ba_2+ than HVA I_Ca. The ω-Conotoxin GVIA (ω-CgTx), a N-type I_Ca blocker, suppressed ∼65％ of the whole-cell HVA I_Ca at the concentration of 1μM. The ω-CgTx-resistant HVA I_Ca was sensitive to nifedipine(10μM), a dihydropyridine(DHP) calcium channel antagonist, which produced an additional blockade by ∼25％ of the drug-free control(∼70％of the ω-CgTx-resistant I_Ca). The combination of 10μM nifedipine and 1μM ω-CgTx left ∼13％ of the drug-free control I_Ca unblocked. The DHP agonist S(-)-BayK8644(5μM) shifted the activation of the HVA I_Ca to more negative potentials and increased its maximal amplitude. Addtionally, S(-)-BayK8644 caused the appearance of a slowed component of fail current. These results clearly demonstrate that the presence of two types of sodium channels, TTX-sensitive and resistant, and three types of calcium channels, T-, L- and N-type, in the small-sized adult rat trigeminal ganglion neurons.

목차 (Table of Contents)

• Voltage-Dependent Sodium And Calcium Currents In Acutely Isolated Adult Rat Trigeminal Root Ganglion Neurons
• ABSTRACT
• Introduction
• Methods
• Results
• Discussion
• Acknowledgments
• References
• Figure Legends
• Illustrations
• Effects of Various Neurotransmitters on the Intracellular Cacium Concentration in Trigeminal Ganglion Neurons
• Introduction
• Materials and Methods
• Results
• References
• Isolation of medullary dorsal horn neurons and characteristics of membrane currents
• 1.Introduction
• 2.Materials and Methods
• 3.Results
• 4.Discussion
• References
• Figure Legend