5-hydroxytryptamine activates a barium-sensitive, cAMP-mediated potassium conductance in the leech giant glial cell
5-hydroxytryptamine activates a barium-sensitive, cAMP-mediated potassium conductance in the leech giant glial cell
复制标题
DOI：
10.1002/glia.20120
复制
发表时间：
2005-02-01
期刊：
影响因子：
6.2
通讯作者：
Deitmer, JW
中科院分区：
文献类型：
--
作者：
Britz, FC;Hirth, IC;Deitmer, JW
5-Hydroxytryptamine (5-HT), a neurotransmitter and neuromodulator in the central nervous system of the leech Hirudo medicinalis hyperpolarizes the giant glial cell in the neuropil of segmental ganglia at micromolar concentrations. The 5-HT-evoked glial response (EC50 approximate to2.5 muM) is mediated by a non-desensitizing, G-protein-coupled receptor and due to activation of a Ca2+ -independent K+ conductance. The adenylyl cyclase inhibitor SQ22,536 blocks the response to 5-HT; in the presence of 1 mM db-cAMP, but not of 1 mM db-cGMP, the glial response is suppressed. The 5-HT-evoked response is reduced by Ba2+ with half-maximal inhibition at 50 muM Ba2+. The results suggest that release of 5-HT from serotonergic neurons, or the maintenance of micromolar levels of extracellular 5-HT in the ganglion, may help to set the glial membrane potential close to the K+ equilibrium potential. (C) 2004 Wiley-Liss, Inc.
