The functional significance of TrkB phosphorylation in the rat nucleus accumbens as a molecular switch of habit formation in drug addiction

TrkB和核糖体蛋白S6的磷酸化在活性依赖的蛋白质合成中起着关键作用，有助于神经元的可塑性和学习/记忆。在本研究中，我们观察了反复给予生理盐水或可卡因后，可卡因刺激对大鼠伏隔核TrkB和rpS6重要磷酸化位点的影响。至于TrkB，我们研究了两个不同的磷酸化位点，一个是记忆获得所必需的，另一个是记忆巩固所必需的。同样，对于rpS6，我们检测了两个不同的磷酸化位点，一个是mTOR依赖的，另一个是mTOR非依赖的。结果，我们发现，在对照组和慢性可卡因处理的大鼠中，每个位点的磷酸化模式是如此明显地不同。N-乙酰半胱氨酸对TrkB-MTOT途径的磷酸化没有任何影响，它被认为可以恢复啮齿动物的可卡因寻找行为。

The phosphorylations of TrkB and ribosomal protein S6 that play crucial roles in activity-dependent protein synthesis contribute to neuronal plasticity and learning/memory. In this study, we examined the effect of cocaine challenge on the important phosphorylation sites of TrkB and rpS6 in the rat nucleus accumbens after repeated saline or cocaine administration. As for TrkB, two distinct phosphorylation sites, one is required for memory acquisition, the other is for memory consolidation, were investigated. Likewise, as for rpS6, two distinct phosphorylation sites, one is mTOR-dependent, other is mTOR-independent, were examined. As a result, we found that the pattern of phosphorylation at each site was so distinctively different between control and chronic-cocaine-treated rats. N-acetylcysteine, which is supposed to restore cocaine-seeking behaviors in rodents did not provide any effect on the phosphorylations in TrkB-mTOT pathway.