抄録
The subfornical organ (SFO) is a circumventricular structure and related to drinking behavior. The nucleus can be affected directly by blood-born peptides, because of lacking the blood-brain-barrier. Peripheral and/or central administrations of ghrelin induce food intake while those of amyline inhibit it. Recently, it has been reported that ghrelin and amylin influence separate subpopulations of SFO neurons using patch-clamp recording at dissociated cells. In the present study, we investigated effects of both peptides on spontaneous electrical activity of SFO neurons at slice preparations using multi-electrodes extracellular recording system (MEA system). Bath application of amylin at 100 nM excited 75% of SFO neurons tested. On the other hand, that of ghrelin at 100 or 300 nM did not only excite in 25% of SFO neurons, but also inhibited in 25% of SFO neurons. Similar to the results in a previous study, amylin-sensitive SFO neurons did not show ghrelin-induced excitability. Interestingly, some of them showed ghrelin-induced inhibition. These results suggest that although SFO neurons are excited by either ghrelin or amylin, some amylin-sensitive SFO neurons are inhibited by ghrelin, at least, at slice preparation level. [J Physiol Sci. 2007;57 Suppl:S170]
