Preprotachykinin and preproenkephalin mRNA expression within striatal subregions in response to altered serotonin transmission.
Preprotachykinin and preproenkephalin mRNA expression within striatal subregions in response to altered serotonin transmission.
复制标题
纹状体亚区域内前速激肽和前脑啡肽原 mRNA 表达响应血清素传递的改变。
DOI：
10.1016/0006-8993(96)00483-0
复制
发表时间：
1996
期刊：
影响因子：
2.9
通讯作者：
Carlock,LR
中科院分区：
文献类型：
--
作者：
Walker,PD;Capodilupo,JG;Wolf,WA;Carlock,LR
The effects of lowered serotonin (5-hydroxytryptamine; 5-HT) neurotransmission on preprotachykinin (PPT) and preproenkephalin (PPE) mRNA levels were examined in subregions of the striatum. Adult male rats were treated systemically with para-chlorophenylalanine (pCPA; 350 mg/kg single i.p. injection) which reduced forebrain 5-HT amounts to approximately 20% of saline-injected controls at 24 and 48 h. As measured by Northern analysis, PPT and PPE mRNA levels were elevated 50% and 160% respectively in the anterior ventromedial striatum (region included nucleus accumbens). PPT mRNA levels were raised 90% in posterior striatum (at the level of the globus pallidus) by 48 h post-pCPA injection. To determine if increased PPT and PPE mRNA levels represented a transient response to brief 5-HT inhibition, additional experiments were performed to provide continual suppression of 5-HT within the striatum. First, rats received daily intraperitoneal injections of saline or the 5-HT1Areceptor agonist, 8-OH-DPAT (1 mg/kg), for 7 days to reduce 5-HT release from raphestriatal terminals. In a parallel experiment, the serotonin neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT, 5 μg), was stereotaxically injected into the striatum as a means to permanently remove 5-HT terminals. Although levels of each mRNA species were differentially sensitive to 5,7-DHT or 8-OH-DPAT, PPT and PPE mRNAs were lowered between 30–55% within the anterior dorsolateral and ventromedial striatum. Although these results support previous studies suggesting an overall positive regulatory role of serotonin on striatal tachykinin biosynthesis, PPT and PPE gene regulation in certain striatal subregions may be differentially sensitive to lowered 5-HT neurotransmission. This suggestion is supported by observations that acute systemic stimulation of 5-HT2A/Creceptors with DOI (7 mg/kg single i.p. injection) raised PPT and PPE mRNA levels within anterior dorsolateral (30–60%) and posterior (100–200%) striata, but not within the anterior ventromedial striatum.
