Channelpedia

PubMed 15494982


Referenced in: none

Automatically associated channels: Kir2.3



Title: 5-Hydroxytryptamine activates a barium-sensitive, cAMP-mediated potassium conductance in the leech giant glial cell.

Authors: Frank C Britz, Ingolf C Hirth, Hans-Peter Schneider, Joachim W Deitmer

Journal, date & volume: Glia, 2005 Feb , 49, 309-17

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15494982


Abstract
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 (EC(50) approximately 2.5 microM) is mediated by a non-desensitizing, G-protein-coupled receptor and due to activation of a Ca(2+)-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 Ba(2+) with half-maximal inhibition at 50 microM Ba(2+). 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.