Role of cAMP response element-binding protein in the rat locus ceruleus: Regulation of neuronal activity and opiate withdrawal behaviors
Role of cAMP response element-binding protein in the rat locus ceruleus: Regulation of neuronal activity and opiate withdrawal behaviors
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DOI：
10.1523/jneurosci.4701-05.2006
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发表时间：
2006-04-26
影响因子：
5.3
通讯作者：
Nestler, EJ
中科院分区：
文献类型：
--
作者：
Han, MH;Bolanos, CA;Nestler, EJ
转录因子cAMP反应元件结合蛋白（CREB）参与介导慢性吗啡在蓝斑（LC）中的作用，但支持这种作用的直接证据有限。在这里，我们研究了CREB对LC神经元活性和阿片类戒断行为的影响，通过选择性操纵CREB活性在LC中使用病毒载体编码基因CREBGFP（野生型CREB标记绿色荧光蛋白），caCREBGFP（组成型活性CREB突变体），dnCREBGFP（显性阴性CREB突变体），或单独作为对照的GFP。我们的研究结果表明，在体内过表达CREBGFP的LC显着加剧特定的吗啡戒断行为，而dnCREBGFP表达减弱这些行为。在细胞水平上，CREBGFP在体内和体外LC中的表达在基线时对神经元放电没有显著影响，但增强了毛喉素（腺苷酸环化酶的激活剂）对这些神经元的兴奋作用，这表明CREB表达后这些神经元中的cAMP信号通路被敏化。此外，体外研究表明，与表达GFP的对照细胞相比，表达CaCREBGFP的LC神经元放电明显更快，并且具有更多的去极化静息膜电位。相反，LC神经元的活动减少dnCREBGFP，和神经元超极化的这种治疗。总之，这些数据提供了直接的证据，CREB在控制LC神经元的电兴奋性中起着重要作用，吗啡诱导的CREB活性增加有助于与阿片依赖和戒断相关的行为和神经适应。
The transcription factor cAMP response element-binding protein (CREB) is implicated in mediating the actions of chronic morphine in the locus ceruleus (LC), but direct evidence to support such a role is limited. Here, we investigated the influence of CREB on LC neuronal activity and opiate withdrawal behaviors by selectively manipulating CREB activity in the LC using viral vectors encoding genes for CREBGFP (wild-type CREB tagged with green fluorescent protein), caCREBGFP (a constitutively active CREB mutant), dnCREBGFP (a dominant-negative CREB mutant), or GFP alone as a control. Our results show that in vivo overexpression of CREBGFP in the LC significantly aggravated particular morphine withdrawal behaviors, whereas dnCREBGFP expression attenuated these behaviors. At the cellular level, CREBGFP expression in the LC in vivo and in vitro had no significant effect on neuronal firing at baseline but enhanced the excitatory effect of forskolin (an activator of adenylyl cyclase) on these neurons, which suggests that the cAMP signaling pathway in these neurons was sensitized after CREB expression. Moreover, in vitro studies showed that caCREBGFP-expressing LC neurons fired significantly faster and had a more depolarized resting membrane potential compared with GFP-expressing control cells. Conversely, LC neuronal activity was decreased by dnCREBGFP, and the neurons were hyperpolarized by this treatment. Together, these data provide direct evidence that CREB plays an important role in controlling the electrical excitability of LC neurons and that morphine-induced increases in CREB activity contribute to the behavioral and neural adaptations associated with opiate dependence and withdrawal.