Soukupová Marie, Falcicchia Chiara, Lovisari Francesca, Ingusci Selene, Barbieri Mario, Zucchini Silvia, Simonato Michele
Department of Medical Sciences, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience;
Department of Medical Sciences, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience.
J Vis Exp. 2018 Nov 8(141). doi: 10.3791/58455.
Microdialysis is a well-established neuroscience technique that correlates the changes of neurologically active substances diffusing into the brain interstitial space with the behavior and/or with the specific outcome of a pathology (e.g., seizures for epilepsy). When studying epilepsy, the microdialysis technique is often combined with short-term or even long-term video-electroencephalography (EEG) monitoring to assess spontaneous seizure frequency, severity, progression and clustering. The combined microdialysis-EEG is based on the use of several methods and instruments. Here, we performed in vivo microdialysis and continuous video-EEG recording to monitor glutamate and aspartate outflow over time, in different phases of the natural history of epilepsy in a rat model. This combined approach allows the pairing of changes in the neurotransmitter release with specific stages of the disease development and progression. The amino acid concentration in the dialysate was determined by liquid chromatography. Here, we describe the methods and outline the principal precautionary measures one should take during in vivo microdialysis-EEG, with particular attention to the stereotaxic surgery, basal and high potassium stimulation during microdialysis, depth electrode EEG recording and high-performance liquid chromatography analysis of aspartate and glutamate in the dialysate. This approach may be adapted to test a variety of drug or disease induced changes of the physiological concentrations of aspartate and glutamate in the brain. Depending on the availability of an appropriate analytical assay, it may be further used to test different soluble molecules when employing EEG recording at the same time.
微透析是一种成熟的神经科学技术，它将扩散到脑间质空间中的神经活性物质的变化与行为和/或某种病理状态的特定结果（例如癫痫的发作）联系起来。在研究癫痫时，微透析技术通常与短期甚至长期的视频脑电图（EEG）监测相结合，以评估自发癫痫发作的频率、严重程度、进展和聚集情况。微透析与EEG联合技术基于多种方法和仪器的使用。在此，我们在大鼠模型中进行了体内微透析和连续视频EEG记录，以监测癫痫自然病程不同阶段谷氨酸和天冬氨酸随时间的流出情况。这种联合方法能够将神经递质释放的变化与疾病发展和进展的特定阶段进行配对。透析液中的氨基酸浓度通过液相色谱法测定。在此，我们描述了这些方法，并概述了在体内微透析 - EEG过程中应采取的主要预防措施，尤其关注立体定向手术、微透析过程中的基础和高钾刺激、深度电极EEG记录以及透析液中天冬氨酸和谷氨酸的高效液相色谱分析。这种方法可用于测试各种药物或疾病引起的脑内天冬氨酸和谷氨酸生理浓度的变化。根据合适分析测定方法的可用性，在同时进行EEG记录时，它还可进一步用于测试不同的可溶性分子。
