Presynaptic actions of D2-like receptors in the rat cortico-striato-globus pallidus disynaptic connection in vitro.
Presynaptic actions of D2-like receptors in the rat cortico-striato-globus pallidus disynaptic connection in vitro.
复制标题
D2 样受体在体外大鼠皮质-纹状体-苍白球突触连接中的突触前作用。
DOI：
10.1152/jn.90806.2008
复制
发表时间：
2009
影响因子：
2.5
通讯作者：
Kita,Hitoshi
中科院分区：
文献类型：
--
作者：
Watanabe,Katsushige;Kita,Takako;Kita,Hitoshi
大脑皮质、新纹状体（Str）和苍白球（GPe）的外部段形成皮质-Str-GPe双突触连接，这是基底节回路中的主要连接之一，并且是多巴胺调节的靶点。本研究的目的是检查D2样多巴胺受体（D2 LRs）在这方面的行动，使用大鼠脑片制备。在0 mV电压钳制的充满铯的GPe神经元中，额叶皮层的电刺激诱发双突触抑制性突触后电流（IPSC）。阈值刺激诱发的IPSC较小，<10 pA。浴或局部应用的D2 LR激动剂quinpirole Str降低皮层刺激诱导的IPSC的幅度。电刺激Str诱发GPe神经元中的单突触IPSC。对GPe局部应用奎吡罗可减少Str刺激诱导的IPSC。浴应用喹吡罗降低了被认为是由GPe神经元的局部侧支轴突诱发的大型微型IPSC（mIPSC）的频率。这些结果表明，D2 LRs的激活降低了皮质-Str-GPe双突触连接的获得，这种降低归因于Str和GPe中D2 LRs的激活，并且Str-GPe和GPe-GPe GABA能抑制都受突触前D2 LRs的控制。
The cerebral cortex, the neostriatum (Str), and the external segment of the globus pallidus (GPe) form a cortico-Str-GPe disynaptic connection, which is one of the major connections in the basal ganglia circuitries and a target of dopamine modulation. The aim of this study was to examine the actions of D2-like dopamine receptors (D2LRs) in this connection using rat brain slice preparations. Electrical stimulation of the frontal cortex evoked disynaptic inhibitory postsynaptic currents (IPSCs) in cesium-filled GPe neurons voltage-clamped at 0 mV. The IPSCs evoked by threshold stimulation were small, <10 pA. Bath or local applications of the D2LR agonist quinpirole to Str decreased the amplitude of the cortical stimulation-induced IPSCs. Electrical stimulation of Str evoked monosynaptic IPSCs in GPe neurons. Local application of quinpirole to GPe decreased the Str stimulation-induced IPSCs. Bath application of quinpirole decreased the frequency of large miniature IPSCs (mIPSCs) that were considered to be evoked by local collateral axons of GPe neurons. These results suggested that activation of D2LRs decrease the gain of the cortico-Str-GPe disynaptic connection, with the decrease attributed to activation of D2LRs in Str and GPe, and that both Str-GPe and GPe-GPe GABAergic inhibitions are under the control of presynaptic D2LRs.