NONLINEAR RELATIONSHIP BETWEEN IMPULSE FLOW, DOPAMINE RELEASE AND DOPAMINE ELIMINATION IN THE RAT-BRAIN IN-VIVO
NONLINEAR RELATIONSHIP BETWEEN IMPULSE FLOW, DOPAMINE RELEASE AND DOPAMINE ELIMINATION IN THE RAT-BRAIN IN-VIVO
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DOI：
10.1016/0306-4522(94)90465-0
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发表时间：
1994-10-01
期刊：
影响因子：
3.3
通讯作者：
GONON, F
中科院分区：
文献类型：
--
作者：
CHERGUI, K;SUAUDCHAGNY, MF;GONON, F
中枢多巴胺能神经元表现出两种放电活动：单个棘波和2 ~ 6个动作电位的爆发。（2，4 - 6，8）由于这些神经元可以从一种放电模式切换到另一种，而平均放电率几乎不受影响，因此爆发可能更有效地触发其神经递质多巴胺的释放。（4，6，8）模拟爆发模式的电刺激实际上是规则间隔刺激的两倍，以提高多巴胺细胞外浓度。（3，12）这表明增加脉冲流频率可能促进多巴胺释放。(3)爆发引起的高细胞外溢出也可能是由于释放的多巴胺的积累，而在较低的频率下，多巴胺可能很容易在每个动作电位之间消除。(10在本研究中，通过碳纤维电极结合连续安培法在体内测量由多巴胺能通路的电刺激引起的多巴胺溢出。(1)我们观察到一个小的便利化的释放每个脉冲在刺激模仿爆发，但仅在中脑边缘区。由爆发引起的高细胞外多巴胺水平主要是由于释放的多巴胺的积累。
Central dopaminergic neurons exhibit two kinds of discharge activity: single spikes and bursts of two to six action potentials.(2,4-6,8) Since these neurons can switch from one discharge pattern to the other whereas the mean discharge rate remains little affected, bursts may be more potent in triggering the release of their neurotransmitter, dopamine.(4,6,8) Electrical stimulations mimicking the bursting pattern were actually twice as potent as regularly spaced stimulations to enhance the dopamine extracellular concentration.(3,12) This suggested that dopamine release might be facilitated by increasing the impulse flow frequency.(3) The high extracellular overflow evoked by a burst might also be due to accumulation of the released dopamine whereas, at lower frequencies, dopamine might be readily eliminated between every action potential.(10,19) In the present study the dopamine overflow evoked by electrical stimulation of the dopaminergic pathway was measured in vivo by carbon fibre electrodes combined with continuous amperometry.(1) We observed a small facilitation of the release per pulse during stimulations mimicking a burst but only in mesolimbic areas. The high extracellular dopamine level evoked by a burst was mainly due to accumulation of the released dopamine.