Agardh E
Acta Physiol Scand. 1986 Jan;126(1):33-8. doi: 10.1111/j.1748-1716.1986.tb07785.x.
The release of [3H]acetylcholine from the chick retina was studied. A 5 mM increase in K+-concentration caused an increased release, which was Ca2+-dependent. The effect of 5 mM K+ was neither potentiated by bicuculline nor inhibited by isoguvacine or muscimol. This indicates that the K+-induced release is not controlled by GABA. However, bicuculline and picrotoxin increased the spontaneous efflux of radioactivity, whereas GABA had no significant effect. The results suggest that cholinergic neurons are tonically inhibited by a continuous release of endogenous GABA. Neither glycine or strychnine, nor dopamine or haloperidol had any effect on the spontaneous release.
研究了[3H]乙酰胆碱从鸡视网膜的释放情况。钾离子浓度增加5 mM会导致释放增加，且这种增加依赖于钙离子。5 mM钾离子的作用既不被荷包牡丹碱增强，也不被异鹅掌楸碱或蝇蕈醇抑制。这表明钾离子诱导的释放不受γ-氨基丁酸（GABA）的控制。然而，荷包牡丹碱和苦味毒增加了放射性物质的自发外流，而GABA没有显著影响。结果表明，胆碱能神经元受到内源性GABA持续释放的紧张性抑制。甘氨酸或士的宁、多巴胺或氟哌啶醇对自发释放均无任何影响。
