G-protein-coupled inwardly rectifying potassium channels are targets of alcohol action

10.1038/16012 ◽  
1999 ◽  
Vol 2 (12) ◽  
pp. 1084-1090 ◽  
Author(s):  
Joanne M. Lewohl ◽  
Walter R. Wilson ◽  
R. Dayne Mayfield ◽  
Susan J. Brozowski ◽  
Richard A. Morrisett ◽  
...  
Keyword(s):  
Potassium Channels ◽  
G Protein ◽  
Inwardly Rectifying Potassium Channels ◽  
Inwardly Rectifying ◽  
G Protein Coupled

scholarly journals Galanin Activates G Protein Gated Inwardly Rectifying Potassium Channels and Suppresses Kisspeptin-10 Activation of GnRH Neurons

Endocrinology ◽  
2016 ◽  
Vol 157 (8) ◽  
pp. 3197-3212 ◽  
Author(s):  
Stephanie Constantin ◽  
Susan Wray
Keyword(s):  
Potassium Channels ◽  
G Protein ◽  
Detection Threshold ◽  
Calcium Oscillations ◽  
Inwardly Rectifying Potassium Channels ◽  
Gnrh Neurons ◽  
Series Of Experiments ◽  
Galanin Receptors ◽  
Inwardly Rectifying ◽  
G Protein Coupled

GnRH neurons are regulated by hypothalamic kisspeptin neurons. Recently, galanin was identified in a subpopulation of kisspeptin neurons. Although the literature thoroughly describes kisspeptin activation of GnRH neurons, little is known about the effects of galanin on GnRH neurons. This study investigated whether galanin could alter kisspeptin signaling to GnRH neurons. GnRH cells maintained in explants, known to display spontaneous calcium oscillations, and a long-lasting calcium response to kisspeptin-10 (kp-10), were used. First, transcripts for galanin receptors (GalRs) were examined. Only GalR1 was found in GnRH neurons. A series of experiments was then performed to determine the action of galanin on kp-10 activated GnRH neurons. Applied after kp-10 activation, galanin 1–16 (Gal1–16) rapidly suppressed kp-10 activation. Applied with kp-10, Gal1–16 prevented kp-10 activation until its removal. To determine the mechanism by which galanin inhibited kp-10 activation of GnRH neurons, Gal1–16 and galanin were applied to spontaneously active GnRH neurons. Both inhibited GnRH neuronal activity, independent of GnRH neuronal inputs. This inhibition was mimicked by a GalR1 agonist but not by GalR2 or GalR2/3 agonists. Although Gal1–16 inhibition relied on Gi/o signaling, it was independent of cAMP levels but sensitive to blockers of G protein-coupled inwardly rectifying potassium channels. A newly developed bioassay for GnRH detection showed Gal1–16 decreased the kp-10-evoked GnRH secretion below detection threshold. Together, this study shows that galanin is a potent regulator of GnRH neurons, possibly acting as a physiological break to kisspeptin excitation.

Interaction of Gαq and Kir3, G Protein-Coupled Inwardly Rectifying Potassium Channels

2007 ◽  
Vol 71 (4) ◽  
pp. 1179-1184 ◽  
Author(s):  
Takeharu Kawano ◽  
Peng Zhao ◽  
Christina V. Floreani ◽  
Yasuko Nakajima ◽  
Tohru Kozasa ◽  
...  
Keyword(s):  
Potassium Channels ◽  
G Protein ◽  
Inwardly Rectifying Potassium Channels ◽  
Inwardly Rectifying ◽  
G Protein Coupled
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