Kuhr W G, Wightman R M, Rebec G V
Department of Chemistry, Indiana University, Bloomington 47405.
Brain Res. 1987 Aug 18;418(1):122-8. doi: 10.1016/0006-8993(87)90968-1.
Simultaneous electrical and chemical recordings have been made of dopamine neuronal activity in the rat brain during electrical stimulation of the medial forebrain bundle. Tungsten recording electrodes were placed at the level of the substantia nigra and carbon-fiber, Nafion-coated, voltammetric electrodes were placed in the neostriatum. Dopamine units, verified by histology to be in the zona compacta of the substantia nigra, were identified by previously established electrophysiological criteria. Dopamine release was detected by fast-scan cyclic voltammetry, a technique which allows dopamine to be determined in vivo on a sub-second time scale. The majority of dopamine cells examined (7 out of 10) were antidromically activated by 60 Hz stimulation of the medial forebrain bundle. The same stimulus also elicits dopamine overflow in the caudate nucleus. Following stimulation, dopamine concentrations in the extracellular fluid of the neostriatum rapidly declined to prestimulus levels. In addition, impulse flow in dopaminergic neurons was inhibited for 20 s following stimulation. These measurements represent the first direct observation from a neuronal tract of simultaneous unit activity and chemical release of a neurotransmitter in real time.
在对内侧前脑束进行电刺激期间，已对大鼠大脑中的多巴胺神经元活动进行了同步电记录和化学记录。将钨记录电极置于黑质水平，将碳纤维、涂有Nafion的伏安电极置于新纹状体中。经组织学证实位于黑质致密部的多巴胺神经元，通过先前确立的电生理标准进行识别。通过快速扫描循环伏安法检测多巴胺释放，该技术可在亚秒时间尺度上在体内测定多巴胺。所检查的大多数多巴胺细胞（10个中的7个）通过对内侧前脑束进行60Hz刺激而被逆向激活。相同的刺激也会引发尾状核中的多巴胺溢出。刺激后，新纹状体细胞外液中的多巴胺浓度迅速降至刺激前水平。此外，刺激后多巴胺能神经元中的冲动发放被抑制20秒。这些测量结果代表了首次从神经束中对神经元活动和神经递质化学释放进行实时同步单位活动的直接观察。
