Affiliation:
1. Department of Bio-Plasticity, Kyushu University Faculty of Medicine,Fukuoka, Japan.
Abstract
1. The inhibitory response of exogenously applied glycine was investigated in freshly dissociated rat nucleus tractus solitarii neurons under whole cell configuration using new perforated patch-clamp technique termed "gramicidin perforated patch technique," which maintains intact intracellular Cl- concentrations. 2. Using the gramicidin perforated patch technique, at a holding potential (VH) of -45 mV, glycine induced outward currents in a concentration-dependent manner with a EC50 of 4.0 x 10(-5) M and at a Hill coefficient of 1.5. In contrast, using the nystatin perforated patch technique, glycine induced inward currents at the same VH in a concentration-dependent manner with an EC50 of 4.9 x 10(-5) M and at a Hill coefficient of 1.2. 3. The glycine-induced outward currents were blocked by strychnine in a concentration dependent manner with an IC50 of 2.2 x 10(-8) M. The blockade was competitive. 4. The current-voltage relationship for the 10(-5) M glycine response showed a clear outward rectification. 5. Ten-fold change of extracellular Cl- with a large impermeable anion resulted in a 65 mV shift of the reversal potential of glycine-induced currents (EGly), indicating that the membrane behaves like a Cl- electrode in the presence of glycine. 6. The intracellular Cl- activity calculated from the EGly ranged from 7.3 to 18.2 mM, with a mean value of 13.3 mM. 7. The values of EGly in the individual neurons were significantly negative to the resting membrane potentials, suggesting the existence of active transport of Cl-.
Publisher
American Physiological Society
Subject
Physiology,General Neuroscience
Cited by
56 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献