Nitri oxide augments single Ca channel currents via cGMP-dependent protein kinase in Kenyon cells isolated from the mushroom body of the cricket brain.
Nitri oxide augments single Ca channel currents via cGMP-dependent protein kinase in Kenyon cells isolated from the mushroom body of the cricket brain.
复制标题
在从蟋蟀脑蘑菇体中分离出的 Kenyon 细胞中，一氧化氮通过 cGMP 依赖性蛋白激酶增强单 Ca 通道电流。
DOI：
10.1016/j.jinsphys.2015.04.009
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发表时间：
2015
影响因子：
2.2
通讯作者：
Masami Yoshino
中科院分区：
文献类型：
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作者：
Kumiko Kosakai;Yuuki Tsujiuchi;Masami Yoshino
昆虫的行为学和药理学研究表明，一氧化氮（NO）/环鸟苷酸（cGMP）信号通路参与嗅觉学习相关的长时程记忆（LTM）的形成。然而，NO的靶分子和下游信号通路仍不清楚。在这项研究中，我们调查了行动的NO对单个电压依赖性钙离子通道的内在神经元称为肯扬细胞内的蘑菇体的蟋蟀脑，使用细胞贴附配置的膜片钳技术。NO供体S-亚硝基谷胱甘肽（GSNO）的应用增加了单个Ca~（2+）通道电流的开放概率（NPO）。这种GSNO诱导的增加被可溶性鸟苷酸环化酶（sGC）抑制剂ODQ阻断，表明GSNO产生的NO通过sGC起作用以提高cGMP水平。膜透性cGMP类似物8-Bro-cGMP也增加单个Ca~（2+）通道电流的NPO。用蛋白激酶G阻断剂KT 5823预处理细胞，可阻断GSNO的兴奋作用。提示NO通过cGMP/PKG信号通路增强单个Ca~（2+）通道的活性。为了深入了解NO的生理作用，我们在电流钳条件下研究了GSNO对Kenyon细胞动作电位的影响。GSNO的应用增加了去极化电流注入引起的动作电位的频率，表明NO作为一种调制器，导致在凯尼恩细胞的刺激信号。我们讨论了通过这些Ca2+通道增加的Ca2+内流通过NO/cGMP信号级联与嗅觉LTM的形成。
Behavioral and pharmacological studies in insects have suggested that the nitric oxide (NO)/cyclic GMP (cGMP) signaling pathway is involved in the formation of long-term memory (LTM) associated with olfactory learning. However, the target molecules of NO and the downstream signaling pathway are still not known. In this study, we investigated the action of NO on single voltage-dependent Ca2+channels in the intrinsic neurons known as Kenyon cells within the mushroom body of the cricket brain, using the cell-attached configuration of the patch-clamp technique. Application of the NO donorS-nitrosoglutathione (GSNO) increased the open probability (NPO) of single Ca2+channel currents. This GSNO-induced increase was blocked by ODQ, a soluble guanylate cyclase (sGC) inhibitor, suggesting that the NO generated by GSNO acts via sGC to raise cGMP levels. The membrane-permeable cGMP analog 8-Bro-cGMP also increased theNPOof single Ca2+channel currents. Pretreatment of cells with KT5823, a protein kinase G blocker, abolished the excitatory effect of GSNO. These results suggest that NO augments the activity of single Ca2+channels via the cGMP/PKG signaling pathway. To gain insight into the physiological role of NO, we examined the effect of GSNO on action potentials of Kenyon cells under current-clamp conditions. Application of GSNO increased the frequency of action potentials elicited by depolarizing current injections, indicating that NO acts as a modulator resulting in a stimulatory signal in Kenyon cells. We discuss the increased Ca2+influx through these Ca2+channels via the NO/cGMP signaling cascade in relation to the formation of olfactory LTM.