PILOT--THE ROLE OF PROTEIN KINASE A IN NEUROLOGICAL RESP

许多神经递质和激素通过激活G蛋白偶联受体将它们的信号传递到细胞内，G蛋白偶联受体调节腺酰环化酶；这改变了细胞内cAMP水平，进而改变了cAMP依赖的蛋白激酶(PKA)的活性。来自人类和动物文献的越来越多的证据表明，cAMP/PKA系统的遗传变异改变了寻求酒精的行为和对这种药物的急性生理反应。我们最近发现，与野生型小鼠(RIIbeta+/+)相比，完全缺乏PKA RIIbeta亚单位(RIIbeta-/-)的转基因小鼠显示出6%、10%和20%(v/v)的乙醇消耗量增加。此外，RIIbeta-/-小鼠对酒精的镇静作用不那么敏感，这是通过翻正反射丧失的时间来衡量的。需要检验的主要假设是，特定大脑区域的PKA活动调节着对酒精的敏感性和摄入量。作为一种描述PKA的RIIbeta亚单位调节酒精敏感性的大脑区域的策略，Aim 1将测量酒精诱导的RIIbeta-/-和RIIbeta+/+小鼠的c-Fos表达。目标2将确定PKA信号是否调节大脑区域的自愿乙醇消耗，在那里PKA信号调节对乙醇急性影响的敏感性。将cAMP/PKA刺激剂(Sp-cAMP)或抑制剂(Rp-cAMP)注入特定脑区后，将测定RIIbeta-/-和RIIbeta+/+小鼠的酒精摄取和敏感性参数。在该项目期间收集的数据将为R01赠款的未来发展提供基础。

Many neurotransmitters and hormones transduce their signal into a cell by activating G-protein-coupled receptors that modulate adenylyl cyclase; this changes intracellular cAMP levels which subsequently alters cAMP-dependent protein kinase (PKA) activity. A growing body of evidence from both the human and animal literature suggests that genetic variation of the cAMP/PKA system alters ethanol-seeking behavior and acute physiological responses to this drug. We have recently found that genetically altered mice completely lacking production of the RIIbeta subunit of PKA (RIIbeta -/-) showed increased consumption of 6%, 10%, and 20% (v/v) ethanol when compared to wild-type mice (RIIbeta +/+). Furthermore, the RIIbeta -/- mice are less sensitive to the sedative effects of ethanol as measured by duration of the loss of righting reflex. The main hypothesis to be tested is that PKA activity in specific brain regions modulates ethanol sensitivity and intake. As a strategy for delineating brain regions where RIIbeta subunit of PKA modulates ethanol sensitivity, Aim 1 will measure ethanol-induced c-Fos expression in RIIbeta -/- and RIIbeta +/+ mice. Aim 2 will determine if PKA signaling modulates voluntary ethanol consumption in brain regions where PKA signaling modulates sensitivity to the acute effects of ethanol. Parameters of ethanol ingestion and sensitivity will be determined in RIIbeta -/- and RIIbeta +/+ mice following infusion of cAMP/PKA stimulator (Sp-cAMPs) or inhibitor (Rp-cAMPs) into specific brain regions. Data collected during this project would provide a foundation for the future development of an R01 grant.