Focal bicuculline increases extracellular dopamine concentration in the nucleus accumbens of freely moving rats as measured by in vivo microdialysis.
Focal bicuculline increases extracellular dopamine concentration in the nucleus accumbens of freely moving rats as measured by in vivo microdialysis.
复制标题
通过体内微透析测量，局部荷包牡丹碱可增加自由活动大鼠伏核中的细胞外多巴胺浓度。
DOI：
10.1016/s0014-2999(99)00699-8
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发表时间：
1999
影响因子：
5
通讯作者：
Yan,Q
中科院分区：
文献类型：
--
作者：
Yan,Q
本研究旨在评估GABA A受体参与调节体内多巴胺释放的丘脑核。采用脑内微透析结合高效液相色谱电化学检测系统（HPLC-EC）测定了自由活动的Sprague-Dawley大鼠中脑背外侧核细胞外多巴胺的含量。通过透析探针分别将GABA A受体拮抗剂荷包牡丹碱和GABA A受体激动剂蝇蕈醇注入延髓核。结果显示，25、50和100 μM浓度的荷包牡丹碱灌注引起丘脑背核细胞外多巴胺的显著和浓度依赖性增加。多巴胺水平在荷包牡丹碱灌注终止后40-60分钟内恢复至对照值。100 μM荷包牡丹碱灌流引起的多巴胺增加对河豚毒素钠通道阻滞敏感，蝇蕈醇（25和50 μM）以浓度相关方式拮抗。单独灌注25或50 μM蝇蕈醇不能改变多巴胺的基础水平。结果表明，局部应用荷包牡丹碱通过受体介导的过程增加多巴胺释放在脑桥核，并与基础多巴胺释放在脑桥核的紧张性抑制控制下的GABA A受体在此结构的概念是一致的。
This study was designed to assess the involvement of GABAAreceptors in the regulation of in vivo dopamine release in the nucleus accumbens. Extracellular dopamine in the nucleus accumbens was measured using intracerebral microdialysis coupled with a high-performance liquid chromatography with electrochemical detection (HPLC–EC) system in freely moving Sprague–Dawley rats. Bicuculline, a GABAAreceptor antagonist, and muscimol, a GABAAreceptor agonist, were administered via a dialysis probe into the nucleus accumbens, respectively. The results showed that perfusion with bicuculline at concentrations of 25, 50, and 100 μM elicited a significant and concentration-dependent increase in extracellular dopamine in the nucleus accumbens. Dopamine levels returned to control values within 40–60 min after the termination of bicuculline perfusion. The increased dopamine produced by perfusion with 100 μM bicuculline was sensitive to sodium channel blockade with tetrodotoxin, and antagonized by co-perfusion with muscimol (25 and 50 μM) in a concentration-related fashion. Perfusion with 25 or 50 μM muscimol alone failed to alter basal levels of dopamine. The results suggest that local application of bicuculline increases dopamine release in the nucleus accumbens via a receptor-mediated process, and are consistent with the concept that basal dopamine release in the nucleus accumbens is under tonic inhibitory control by GABAAreceptors within this structure.