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

Concurrent EEG Recording을 통한 쥐의 Cerebrospinal Fluid and Blood Withdrawal from Rats with Concurrent EEG Recording(동시 EEG 기록이 있는 쥐의 뇌척수액 및 혈액 철수)

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.

저자 스포트라이트: Obtaining High-quality CSF and Blood Samples for Epilepsy Biomarker Discovery(간질 바이오마커 발견을 위한 고품질 뇌척수액 및 혈액 샘플 획득) 

EEG 기록 중 쥐의 측면 꼬리 정맥에서 뇌척수액 및 혈액 샘플링

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  

발작 활동 분석을 위한 간질 쥐의 테더 비디오-EEG

시작하려면 동물을 녹음실의 깨끗한 케이지에 넣어 새로운 환경에 적응할 수 있도록 합니다. EEG 신호에서 환경 전자기장의 간섭을 피하기 위해 케이지를 패러데이 케이지에 놓습니다. 녹음 케이블의 한쪽 끝을 녹음 장치에 연결합니다.전압계를 사용하여 전위를 측정하고 접지 전극과 기준 전극을 구별합니다. 그런 다음 동물의 머리에 시멘트 덮개를 잡고 녹음 케이블의 다른 쪽 끝을 쥐의 머리에 고정된 전극 커넥터에 삽입합니다. 정류자를 사용하여 녹음 케이블의 무게를 상쇄하고 케이블을 비틀지 않고 동물을 자유롭게 움직일 수 있습니다.등록을 시작하기 전에 EEG에서 데이터를 수집하고 처리하는 데 사용되는 모든 설정을 확인하십시오. EEG 신호의 아티팩트와 노이즈를 방지하기 위해 적절한 필터링 및 샘플링 속도가 적용되었는지 확인합니다. 모니터에서 비디오 녹화 및 EEG 녹화를 시작합니다.시간 경과에 따른 특정 주파수 대역의 전력을 확인하여 트레이스가 예상 EEG 신호와 일치하는지 확인합니다. EEG 추적을 주기적으로 확인하십시오. 또한 동물을 확인하십시오.녹음 케이블이 전극 커넥터에서 분리되면 다시 연결하고 EEG 신호가 깨끗한지 확인하십시오. EEG 기록을 통해 스크리닝하여 EEG 신호를 분석하고 발작과 유사한 활동을 식별합니다. EEG와 동시에 수집된 동기화된 비디오 녹화를 확인하여 잠재적인 경련 발작을 확인합니다.

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 ...