Name: Tethered Video-EEG in Epileptic Rats for Analyses of Seizure Activity
Uploaded: 2023-09-01T13:40:00
Description: Watch this Scientific Journal Video about Tethered Video-EEG in Epileptic Rats for Analyses of Seizure Activity at JoVE.com

tethered video-eeg in epileptic rats for analyses of seizure activity

同时记录脑电图的大鼠脑脊液和血液

Cerebrospinal fluid (CSF) and blood sampling are important to identify and validate biomarkers of epilepsy, in both preclinical and clinical research1,2. Nowadays, the diagnosis of epilepsy and most of the research on epilepsy biomarkers focus on EEG and neuroimaging3,4,5. These approaches, however, present several limitations. Apart from routine scalp measurements, in many cases, EEG requires invasive techniques like depth electrodes6. Brain imaging methods have poor temporal and spatial resolution and are relatively expensive and time-consuming7,8. For this reason, the identification of non-invasive, low-cost, and biofluid-based biomarkers would provide a very attractive alternative. In addition, these biofluid biomarkers could be combined with available diagnostic approaches to sharpen their predictiveness.
Patients diagnosed with epilepsy are routinely submitted to EEG9,10 and blood sampling11,12,13,14, and many also to CSF withdrawal to exclude life-threatening causes (i.e., acute infections, autoimmune encephalitis)15. These blood and CSF samples can be used in clinical research aiming to identify biomarkers for epilepsy. For example, Hogg and co-workers have found that an increase in three plasma tRNA fragments precedes seizure occurrence in human epilepsy14. Similarly, interleukin-1beta (IL-1&#946;) levels in human CSF and serum, expressed as ratio of IL-1&#946; levels in CSF over serum, can predict post-traumatic epilepsy development after traumatic brain injury16. These studies highlight the importance of biofluids sampling for epilepsy biomarkers research, but they face multiple limitations intrinsic to clinical trials, e.g., the cofounding factor of anti-epileptic drugs (AEDs) in blood, the frequent lack of etiology information, inadequate controls, modest numbers of patients, and others17,18.
Pre-clinical research offers other opportunities for investigating molecules in biofluids as potential biomarkers for epilepsy. In fact, it is possible to withdraw plasma and/or CSF from animals while performing EEG recordings. Moreover, sampling can be performed repeatedly across multiple days of the experiment, and a number of age, sex, and epileptic insult-matched controls can be used to improve the study&#39;s robustness. Here, a flexible technique to obtain CSF from cisterna magna with parallel withdrawal of plasma from the tail vein in EEG-monitored rats is described in detail. The presented technique has several advantages over alternative methods. By using a butterfly needle approach, it is possible to collect CSF several times without compromising the function of EEG electrodes or similar head implants. This represents a refinement of intrathecal catheter withdrawal procedures, which are associated with a relatively high risk of infection. In addition, the reported free fall dropping approach used for blood collection is superior to other approaches of tail vein blood withdrawal because of the highly reduced risk of hemolysis, due to the fact that blood does not pass through tubing and no vacuum pressure is applied. If performed under strict germ-free conditions, there is a particularly low risk of infection for animals. In addition, by starting the blood withdrawals at the very end of the animals&#39; tails, sampling can be repeated several times. Such techniques are easy to master and can be applied in many preclinical studies of central nervous system disorders.

作者聚焦：获取高质量的 CSF 和血液样本以发现癫痫生物标志物 

在脑电图记录期间从大鼠的侧尾静脉采集脑脊液和血液

In our research, we aim to find diagnostic and prognostic biomarkers for epilepsy. In order to validate them in biological liquids, we compare the levels of specific substances in the cerebrospinal fluid and plasma with the occurrence of spontaneous seizures in rats. Today some small non-coding ribonucleic acids like miRNAs or tRNA fragments have been identified as a circulating biomarker for epilepsy, but their utility as an effective and reliable diagnostic or prognostic tool in epilepsy must be confirmed.different circulating markers for epilepsy, we routinely withdraw plasma and CSF of epileptic rats. While performing EEG recording, student find spontaneous seizures. As we repeat the sampling across multiple days, we can correlate the levels of markers with single seizure occurrence or their cumulative effect.The current challenge is to obtain sufficient volume of high quality samples for the following analytical procedures without inducing stress-provoked seizures in animals caused by their manipulation, which may interfere with the levels of molecules under investigation. There is an urgent unmet medical need to discover biomarkers for people with epilepsy, especially the prognostic and risky ones. Plasma and CSF sampling in parallel to EEG seizure monitoring allow the significant advance to find the suitable marker.Our draw tail vein blood withdrawal technique produces high quality hemolysis-free plasma samples, as it does not require a vacuum or tail milking. Cisterna magna puncture that we use to sample CSF has better sterility and a lower risk of head implant loss in comparison to a cannulated system.

Watch this Scientific Journal Video about Tethered Video-EEG in Epileptic Rats for Analyses of Seizure Activity at JoVE.com

Tethered Video-EEG in Epileptic Rats for Analyses of Seizure Activity  

癫痫大鼠的系留视频脑电图用于癫痫发作活动分析

首先，将动物放在录音室的干净笼子里，让它们适应新环境。将笼子放入法拉第笼中，以避免脑电信号中环境电磁场的干扰。将录音电缆的一端连接到录音设备。使用电压表测量电势并区分接地电极和参比电极。然后将水泥盖固定在动物的头上，将记录电缆的另一端插入固定在大鼠头部的电极连接器中。使用换向器来平衡记录电缆的重量，并允许动物在不扭曲电缆的情况下自由移动。在开始注册之前，请检查用于从 EEG 获取和处理数据的所有设置。确保应用足够的滤波和采样率，以避免脑电图信号中的伪影和噪声。在监视器上开始视频录制和脑电图录制。检查特定频段内随时间变化的功率，以确保迹线与预期的 EEG 信号匹配。定期检查脑电图轨迹。另外，检查动物。如果记录电缆从电极连接器上脱落，请重新连接并检查是否有清晰的脑电图信号。通过脑电图记录进行筛选来分析脑电图信号，并识别癫痫样活动。通过检查与脑电图同时收集的同步视频记录来确认潜在的惊厥性癫痫发作。

Research

JoVE Journal

Neuroscience

Tethered Video-EEG in Epileptic Rats for Analyses of Seizure Activity

Sampling Cerebrospinal Fluid and Blood from Lateral Tail Vein in Rats During EEG Recordings

Because the composition of body fluids reflects many physiological and pathological dynamics, biological liquid samples are commonly obtained in many ...