ELECTROPHYSIOLOGICAL EFFECTS OF DERMORPHIN ON LOCUS-CERULEUS NEURONS OF RAT

被引：12

作者：

CHIU, TH ^{[1
]}

CHEN, TY ^{[1
]}

HO, CL ^{[1
]}

CHIANG, ST ^{[1
]}

机构：

[1] ACAD SINICA,INST BIOL CHEM,TAIPEI 115,TAIWAN

来源：

NEUROPHARMACOLOGY | 1990年 / 29卷 / 08期

关键词：

brain slices; dermorphin; intracellular recording; locus coeruleus;

D O I：

10.1016/0028-3908(90)90128-E

中图分类号：

Q189 [神经科学];

学科分类号：

071006 ;

摘要：

Intracellular recording was used to study the effects of dermorphin on neurons of the locus coeruleus in the rat, in a totally submerged brain slice preparation. Dermorphin caused the inhibition of spontaneous firing of all neurons of the locus coeruleus tested, with an IC50 of 7 nM. Based on the inhibition of spontaneous firing rate, dermorphin was 16.5 times more potent than morphine. Larger concentrations of dermorphin (30-100 nM) further hyperpolarized the neurons of the locus coeruleus and simultaneously caused a reduction in input resistance. These effects were antagonized by naloxone, with a dissociation equilibrium constant of 0.8 nM. The hyperpolarization of neurons of the locus coeruleus, caused by dermorphin, was reversed at a membrane potential of -112mV in this preparation. Furthermore, this hyperpolarization was blocked by cesium chloride and barium chloride. Thus, these data suggest that dermorphin binds to μ-opioid receptors on the cell membrane of neurons of the locus coeruleus. This leads to opening of the inward-going rectification potassium channels, resulting in the observed hyperpolarization of the membrane. © 1990.

引用

页码：747 / 755

页数：9

共 34 条

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