Calcium-dependent prepotentials contribute to spontaneous activity in rat tuberomammillary neurons

被引:35
作者
Stevens, DR
Haas, HL
机构
[1] Physiologie Institüt II, Heinrich-Heine-Universität, 40001 Düsseldorf
来源
JOURNAL OF PHYSIOLOGY-LONDON | 1996年 / 493卷 / 03期
关键词
D O I
10.1113/jphysiol.1996.sp021419
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
1. Intracellullar recordings from histaminergic neurons of the tuberomammillary (TM) nucleus reveal subthreshold depolarizing potentials (DPs) which persist in the presence of tetrodotoxin. 2. Block of hyperpolarization-activated current 1-4 mM Cs+ failed to reduce spontaneous activity or DPs. 3. In the presence of tetrodotoxin DPs are voltage dependent and are depressed by Cd2+ and Co2+. 4. Ba2+ (100 mu M) treatment enhances DP amplitude and converts low-amplitude potentials to tetrodotoxin-insensitive action potentials. 5. In the presence of TTX, DPs are reduced by Ni2+. Spontaneous action potentials are also reduced by Ni2+ (100-300 mu M). A law-threshold Ca2+ current is present which is sensitive to Ni2+. These results indicate the presence of calcium currents, perhaps of the low-threshold type, which contribute to activation of action potentials in TM neurons.
引用
收藏
页码:747 / 754
页数:8
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