Hernández Adán, Sierra Arturo, Valdiosera René, Florán Benjamin, Erlij David, Aceves Jorge
Departamento de Fisiología, Biofísica y Neurociencias, CINVESTAV-IPN, Apartado postal 14-740, México 07000, DF, Mexico.
Neurosci Lett. 2007 Oct 2;425(3):188-91. doi: 10.1016/j.neulet.2007.08.026. Epub 2007 Aug 19.
The effects of D1/5 dopamine agonists on spontaneous excitatory postsynaptic currents (sEPSCs) were studied in neurons of the rat globus pallidus using whole-cell recordings in the presence of TTX and bicuculline. In this condition, CNQX abolished the sEPSCs, indicating that they were solely mediated by AMPA receptors. SKF 38393, a D1-like agonist, increased the frequency but not the amplitude of the sEPSCs, suggesting a presynaptic site of action. The increase in frequency was blocked by SCH 23390, a D1/5 antagonist. Quinpirole, a D2-like agonist, decreased the frequency but did not affect the amplitude of the synaptic currents. SKF 38393 increased the frequency of sEPSCs currents, even in presence of quinpirole, indicating that D1/5- and D2-like receptors independently modulate glutamate release upon a single neuron. The results suggest that the dopaminergic control of the glutamate transmission in the globus pallidus may play a role in processing cortical information in the indirect pathway of the basal ganglia.
在存在河豚毒素（TTX）和荷包牡丹碱的情况下，使用全细胞膜片钳记录技术，研究了D1/5多巴胺激动剂对大鼠苍白球神经元自发性兴奋性突触后电流（sEPSCs）的影响。在这种条件下，CNQX消除了sEPSCs，表明它们仅由AMPA受体介导。D1样激动剂SKF 38393增加了sEPSCs的频率，但未增加其幅度，提示其作用位点在突触前。频率的增加被D1/5拮抗剂SCH 23390阻断。D2样激动剂喹吡罗降低了频率，但不影响突触电流的幅度。即使存在喹吡罗，SKF 38393仍增加了sEPSCs电流的频率，表明D1/5和D2样受体在单个神经元上独立调节谷氨酸释放。结果表明，苍白球中谷氨酸传递的多巴胺能控制可能在基底神经节间接通路中处理皮质信息方面发挥作用。
