Burrell Mark H, Atcherley Christopher W, Heien Michael L, Lipski Janusz
Department of Physiology and Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland , Auckland 1142, New Zealand.
Department of Chemistry and Biochemistry, University of Arizona , Tucson, Arizona 85721, United States.
ACS Chem Neurosci. 2015 Nov 18;6(11):1802-12. doi: 10.1021/acschemneuro.5b00120. Epub 2015 Sep 10.
Tonic dopamine (DA) levels influence the activity of dopaminergic neurons and the dynamics of fast dopaminergic transmission. Although carbon fiber microelectrodes and fast-scan cyclic voltammetry (FSCV) have been extensively used to quantify stimulus-induced release and uptake of DA in vivo and in vitro, this technique relies on background subtraction and thus cannot provide information about absolute extracellular concentrations. It is also generally not suitable for prolonged (>90 s) recordings due to drift of the background current. A recently reported, modified FSCV approach called fast-scan controlled-adsorption voltammetry (FSCAV) has been used to assess tonic DA levels in solution and in the anesthetized mouse brain. Here we describe a novel extension of FSCAV to investigate pharmacologically induced, slowly occurring changes in tonic (background) extracellular DA concentration, and phasic (stimulated) DA release in brain slices. FSCAV was used to measure adsorption dynamics and changes in DA concentration (for up to 1.5 h, sampling interval 30 s, detection threshold < 10 nM) evoked by drugs affecting DA release and uptake (amphetamine, l-DOPA, pargyline, cocaine, Ro4-1284) in submerged striatal slices obtained from rats. We also show that combined FSCAV-FSCV recordings can be used for concurrent study of stimulated release and changes in tonic DA concentration. Our results demonstrate that FSCAV can be effectively used in brain slices to measure prolonged changes in extracellular level of endogenous DA expressed as absolute values, complementing studies conducted in vivo with microdialysis.
多巴胺（DA）的静息水平会影响多巴胺能神经元的活性以及快速多巴胺能传递的动力学。尽管碳纤维微电极和快速扫描循环伏安法（FSCV）已被广泛用于在体内和体外定量刺激诱导的DA释放和摄取，但该技术依赖于背景扣除，因此无法提供有关细胞外绝对浓度的信息。由于背景电流的漂移，它通常也不适合长时间（>90秒）记录。最近报道的一种改良的FSCV方法，称为快速扫描控制吸附伏安法（FSCAV），已被用于评估溶液和麻醉小鼠大脑中的静息DA水平。在这里，我们描述了FSCAV的一种新扩展，用于研究药理学诱导的、静息（背景）细胞外DA浓度缓慢发生的变化，以及脑片中相位（刺激）DA的释放。FSCAV用于测量从大鼠获得的浸没纹状体切片中影响DA释放和摄取的药物（苯丙胺、左旋多巴、帕吉林、可卡因、Ro4-1284）引起的吸附动力学和DA浓度变化（长达1.5小时，采样间隔30秒，检测阈值<10 nM）。我们还表明，联合FSCAV-FSCV记录可用于同时研究刺激释放和静息DA浓度的变化。我们的结果表明，FSCAV可有效地用于脑片，以测量以内源性DA细胞外水平的长时间变化，以绝对值表示，补充了在体内用微透析进行的研究。
