فإن الكتاب أود أن أشكر بيدرو A. فالديس هرنانديز، فرانسوا Tadel، ولويد سميث لنصائحهم القيمة ومناقشات مثمرة. كما نشكر رافائيل توريس للقراءة واقية.

<ol>
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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standardized+low+resolution+brain+electromagnetic+tomography+(sLORETA):+technical+details.">Standardized low resolution brain electromagnetic tomography (sLORETA): technical details.</a> Methods &amp; Findings in Experimental &amp; Clinical Pharmacology. 24 (D), 5-12 (2002).</li><li>Iijima, T., Nakamura, Z., Iwao, Y., Sankawa, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Epileptogenic+Properties+of+the+Volatile+Anesthetics+Sevoflurane+and+Isoflurane+in+Patients+with+Epilepsy.">The Epileptogenic Properties of the Volatile Anesthetics Sevoflurane and Isoflurane in Patients with Epilepsy.</a> Anesthesia and Analgesia. 91 (4), 989-995 (2000).</li><li>Quiroga, Q. R., Nadasdy, Z., Ben-Shaul, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unsupervised+spike+detection+and+sorting+with+wavelets+and+super-paramagnetic+clustering.">Unsupervised spike detection and sorting with wavelets and super-paramagnetic clustering.</a> Neural Computation. 16 (8), 1661-1687 (2004).</li><li>Delorme, A., Makeig, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EEGLAB:+an+open+source+toolbox+for+analysis+of+single-trial+EEG+dynamics+including+independent+component+analysis.">EEGLAB: an open source toolbox for analysis of single-trial EEG dynamics including independent component analysis.</a> Journal of Neuroscience Methods. 134 (1), 9-21 (2004).</li><li>Oostenveld, R., Fries, P., Maris, E., Schoffelen, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=FieldTrip:+Open+Source+Software+for+Advanced+Analysis+of+MEG,+EEG,+and+Invasive+Electrophysiological+Data.">FieldTrip: Open Source Software for Advanced Analysis of MEG, EEG, and Invasive Electrophysiological Data.</a> Computational Intelligence and Neuroscience. 2011, 1-9 (2011).</li><li>Koessler, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Source+localization+of+ictal+epileptic+activity+investigated+by+high+resolution+EEG+and+validated+by+SEEG.">Source localization of ictal epileptic activity investigated by high resolution EEG and validated by SEEG.</a> NeuroImage. 51 (2), 642-653 (2010).</li><li>Manganotti, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scalp+topography+and+source+analysis+of+interictal+spontaneous+spikes+and+evoked+spikes+by+digital+stimulation+in+benign+rolandic+epilepsy.">Scalp topography and source analysis of interictal spontaneous spikes and evoked spikes by digital stimulation in benign rolandic epilepsy.</a> Electroencephalography and Clinical Neurophysiology. 107 (1), 18-26 (1998).</li><li>Bae, J., Deshmukh, A., Song, Y., Brain Riera, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Source+Analysis+of+Interictal+Epileptiform+Discharges+Using+a+Rat+Model+of+Focal+Epilepsy.">Source Analysis of Interictal Epileptiform Discharges Using a Rat Model of Focal Epilepsy.</a> Organization for Human Brain Mapping. , (2014).</li><li>Birot, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Head+model+and+electrical+source+imaging:+A+study+of+38+epileptic+patients.">Head model and electrical source imaging: A study of 38 epileptic patients.</a> NeuroImage: Clinical. 16 (5), 77-83 (2014).</li><li>Riera, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pitfalls+in+the+dipolar+model+for+the+neocortical+EEG+sources.">Pitfalls in the dipolar model for the neocortical EEG sources.</a> Journal of Neurophysiology. , (2012).</li><li>Hawrylycz, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Allen+Brain+Atlas.">The Allen Brain Atlas.</a> Springer Handbook of Bio-Neuroinformatics. , 1111-1126 (2014).</li><li>Schweinhardt, P., Fransson, P., Olson, L., Spenger, C., Andersson, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+template+for+spatial+normalization+of+MR+images+of+the+rat+brain.">A template for spatial normalization of MR images of the rat brain.</a> Journal of Neuroscience Methods. 129 (2), 105-113 (2003).</li><li>Schwarz, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+stereotaxic+MRI+template+set+for+the+rat+brain+with+tissue+class+distribution+maps+and+co-registered+anatomical+atlas:+application+to+pharmacological+MRI.">A stereotaxic MRI template set for the rat brain with tissue class distribution maps and co-registered anatomical atlas: application to pharmacological MRI.</a> Neuroimage. 32 (2), 538-550 (2006).</li></ol>

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ووصف منهجية جديدة لسجل غير جراحية متعددة EEG في نموذج ما قبل السريرية معين من الصرع البؤري. ، مع نصائح تجريبية محددة، يتم توفير تفاصيل عن إجراءات تسجيل وتحليل. هناك عوامل رئيسية للنظر في تحقيق نتائج ناجحة. أولا، لتسجيلات EEG، والحصول على إشارات عالية الجودة أمر ضروري. وينبغي تطبيق اللزوجة المناسبة من معجون EEG إلى كل قطب كهربائي أثناء إعداد مصغرة كأب، والرأس والأذن شعر فأر يجب إزالتها تماما خلال الحلاقة. الاختيار مقاومة هو أهم خطوة لتأكيد جودة التسجيلات EEG. ثانيا، لتصوير مصدر الدماغ، وتوليد السليم نموذج حجم موصل أمر بالغ الأهمية. وينبغي أن تشارك في تسجيل كل السطح. أيضا، يجب أن يكون مواقف القطب ولدت الحد الأدنى بعد خطأ من المواقع القطب الفعلية على فروة الرأس الفأر. على الرغم من هذه المخطوطة يقدم المصدر، فإنها يمكن أن تجرى إجراءات التحليل باستخدام العصف الذهني 12 باستخدام برامج أخرى مفتوحة 16،17 والمنتجات التجارية 18،19. أيضا، إلى جانب sLORETA 13، حلول عكسية أخرى مثل نماذج متعددة ثنائي القطب وBeamformer يمكن تطبيق 4. واحد الحد من هذا النهج هو أن تحليل السلوك لا يمكن أن تتم منذ يتم تسجيل EEG تحت التخدير. ومع ذلك، بالمقارنة مع الطرق الأخرى لتسجيل EEG في الفئران 5،6، وهذا النهج هو موسع. النتائج الأولية لدينا الدعم على أهمية تصنيف دقيق للعلامات العبوات الناسفة من تسجيلات EEG لتحديد مناطق مهيجة في الفئران يعانون من الصرع البؤري، وكذلك لتقييم علاقتها مع الآليات الكامنة وراء الاستيلاء بدء 11. بالإضافة إلى ذلك، فقد تبين أن ترجمة مصدر EEG لمثل هذه العبوات الناسفة محددة أظهر المراسلات جيدة مع التركيبتفعيل والتعطيل المناطق BOLD ective 20. ودراستنا تحفيز استخدام نماذج ما قبل السريرية لتقييم استراتيجيات سرير مقاعد البدلاء السرير وضعت من قبل المهندسين الطب الحيوي. على سبيل المثال، يتم تنفيذ استخراج العبوات الناسفة في الوقت الحاضر في المستشفيات يدويا، الأمر الذي يتطلب جهدا إنسانيا كبيرا. المنهجية المقترحة في هذه الدراسة يفعل تلقائيا. نحن نفترض أن استخدام هذه المنهجية إلى نتائج مماثلة عند تطبيقها على المرضى الذين يعانون من FCD. نحن نستعد بروتوكولات IRB لتقييم هذه وغيرها من جوانب منهجية في مجموعة البيانات البشري. وعلاوة على ذلك، فإن استخدام نماذج ما قبل السريرية تساعدنا على فهم قدرات وحدود EEG مصدر التعريب في الصرع 21. تقدير دقيق لمصادر الدماغ تلميذه epileptogenesis أمر بالغ الأهمية لاستراتيجيات علاجية والتخطيط الجراحي. أيضا، وجود منصة موحدة لتسجيل EEG في الفئران سيكون مفيدا للتقييم فعالية العديد من العقاقير المضادة للصرع في التجارب ما قبل السريرية. هذه هي الدراسة الأولى التي تسجل الفئران صرع غير جراحية تحت التخدير، والذي سيفتح أبوابا جديدة لتقييم المؤشرات الحيوية EEG لعلاج الصرع. ومع ذلك، فإن منهجية كاملة المعروضة في هذه الدراسة هي قابلة للتمديد لظروف تجريبية أخرى واضطرابات الدماغ. وEEG ميني كاب يمكن أن تستخدم أيضا في أنواع القوارض الأخرى. في الماضي، وقد استخدم نموذج التحفيز forepaw في فئران ويستار لتقييم جودة واستنساخ البيانات المسجلة مع EEG ميني كاب 2. وعلاوة على ذلك، تم تنفيذها التصديقات لإعادة إعمار مصدر الدماغ من الجمجمة عالية الدقة EEG سجلت بالتزامن مع الصفحي امكانات الحقل المحلية من فئران ويستار تحت نموذج التحفيز الطولي 22. وقد تم تطوير هذه المنهجية بالنسبة للفئران ويستار بسبب وجود أطلس MRI لهذه الصورة الفئران معينقطار. ومع ذلك، فإنه يمكن تطبيقها على أنواع القوارض الأخرى مع شكل موحد من أطلس بما في ذلك الماوس 23 والجرذان سبراج داولي 24، وPaxinos واتسون الفئران 25. وبالإضافة إلى ذلك، يمكن أن تستخدم الإجراءات الأساسية للمنهجية المقترحة لدينا في أي القوارض نماذج ما قبل السريرية التي EEG هو طريقة هامة. ومع ذلك، فإن العديد من جوانب هذه المنهجية بشكل خاص لعلاج الصرع، وخاصة تلك المتعلقة EEG تجهيزها (كشف العبوات الناسفة والتصنيف). أيضا، يجب أن يكون الباحثون على علم العقاقير المناسبة المستخدمة في التخدير في حالات مختلفة. وقد اعتبر استخدام الأيزوفلورين وdexdomitor في دراستنا بعناية نظرا لتأثير انخفاض على العبوات الناسفة. وفيما يتعلق تسجيلات EEG، في حالة من الماوس، فإن مساحة فروة الرأس صغيرة نسبيا تقلل من عدد من القنوات إلى حد كبير.

It has been shown that interictal epileptiform discharges (IEDs) observed from EEG constitute useful markers of epileptogenesis in patients with focal epilepsy3. The regions inside the brain from which these IEDs originate, named irritative zones, can in practice be localized based on EEG recordings4. Preclinical models are essential to find correlates between these irritative zones and the actual regions underlying seizure initiation. However, recording EEG from small animals is challenging because of the small surface area of the head compared to the human scalp. Although invasive methods for chronic recording in rats can be used5, 6, techniques are not available at this moment to acquire traditional EEG recordings on rodents under acute conditions without the need of anesthesia.
To solve this problem, we apply a patented EEG mini-cap2, which allows us to record 32-channel EEG data from rodents noninvasively. In this study, we also provide evidence about the need of an analgesic to preserve IED frequency. Therefore, although fixation of EEG mini-cap was performed under isoflurane, EEG recordings were obtained with rats only under sedation (dexdomitor)7. The method proposed in this study can be used in any preclinical rat model of focal epilepsy. To illustrate the capabilities of this methodology, we apply it to understand the correlates between irritative and seizure-onset zones in focal cortical dysplasia (FCD). To that end, we use a &#8220;double-hit&#8221; model of FCD8 in Wistar rats.
To perform brain source analysis, it is required to: a) accurately extract IEDs from EEG raw data and b) obtain a volume conductor model for the individual animal head. To generate a practical volume conductor model, we use an in vivo rat MRI atlas, comprising average images of intensity/shape and obtained via non-linear registration of T2 images of 31 Wistar rats9. The forward model for the generated volume conductor was computed by boundary element method (BEM)10. As in the case of humans, two typical patterns of IEDs (sharp-waves and spikes) were detected and sub-classified into different clusters through an intelligent feature extraction, feature selection, and classification process11. These sub-classified signals are used to estimate the brain source localizations associated with different types of irritative zones. We present the source analysis steps using a well-known public software called Brainstorm12. The EEG source localizations for each IED sub-type and the seizure onset time frames were performed using standardized low-resolution brain electromagnetic tomography (sLORETA)13, which is available in Brainstorm.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Data Qcquisition Computer</td>
			<td>Hewlett-Packard</td>
			<td>Z210 Workstation</td>
			<td></td>
		</tr>
		<tr>
			<td>Dexdomitor</td>
			<td>Orion Pharma</td>
			<td>6295000</td>
			<td>Dexmedetomidine hydrochloride</td>
		</tr>
		<tr>
			<td>EEG Analysis Software</td>
			<td>The Mathworks Inc.</td>
			<td>MATLAB R2011b</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td>Brainstorm</td>
			<td>Sylvain et al. 2001</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td>OpenMEEG</td>
			<td>Bramfort et al. 2010</td>
		</tr>
		<tr>
			<td>EEG Data Streamer</td>
			<td>Tucker-Davis Technologies</td>
			<td>RS4 Data Streamer</td>
			<td></td>
		</tr>
		<tr>
			<td>EEG Electrode Paste</td>
			<td>Biotach</td>
			<td>YGB 103</td>
			<td></td>
		</tr>
		<tr>
			<td>EEG Preamplifier</td>
			<td>BioSemi</td>
			<td>Active Two</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td>Brain Products</td>
			<td>BrainAmp</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td>Tucker-Davis Technologies</td>
			<td>PZ3 Low Impedance Amplifier</td>
			<td></td>
		</tr>
		<tr>
			<td>EEG Processor</td>
			<td>Tucker-Davis Technologies</td>
			<td>RZ2 BioAmp Processor</td>
			<td></td>
		</tr>
		<tr>
			<td>EEG Recording Software</td>
			<td>Tucker-Davis Technologies</td>
			<td>OpenEx - OpenDeveloper</td>
			<td></td>
		</tr>
		<tr>
			<td>EEG SCSI Connector</td>
			<td>BioSemi</td>
			<td>Active Two SCSI Connector</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td>Brain Products</td>
			<td>D-sub Connector</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td>Tucker-Davis Technologies</td>
			<td>Zif-Clif Digital Headstage</td>
			<td></td>
		</tr>
		<tr>
			<td>High Resolution EEG Mini-cap</td>
			<td>Cortech Solutions</td>
			<td>DA-AR-ELRCS32</td>
			<td>US patent Application No. 13/641,834</td>
		</tr>
		<tr>
			<td>Isoflurane, USP</td>
			<td>VedcoPiramal Healthcare</td>
			<td>NDC 66794-013-25</td>
			<td></td>
		</tr>
		<tr>
			<td>Isopropyl Alcohol</td>
			<td>Aqua Solutions</td>
			<td>3112213</td>
			<td>90% v/v solution</td>
		</tr>
		<tr>
			<td>Lubricant Ophthalmic Ointment</td>
			<td>Rugby</td>
			<td>NDC 0536-6550-91</td>
			<td>Sterile</td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Abbott</td>
			<td>2B8203</td>
			<td>Vaterinary 0.9% Sodium Chroride Injection USP</td>
		</tr>
		<tr>
			<td>Physiology Recording Software</td>
			<td>ADInstruments</td>
			<td>LabChart 7.0</td>
			<td></td>
		</tr>
		<tr>
			<td>Physiology Recording System</td>
			<td>ADInstruments</td>
			<td>PowerLab 8/35</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>Monoject</td>
			<td>200555</td>
			<td>12cc</td>
		</tr>
	</tbody>
</table>

brain source imaging in preclinical rat models of focal epilepsy using high-resolution eeg recordings

Electroencephalogram (EEG) has been traditionally used to determine which brain regions are the most likely candidates for resection in patients with focal epilepsy. This methodology relies on the assumption that seizures originate from the same regions of the brain from which interictal epileptiform discharges (IEDs) emerge. Preclinical models are very useful to find correlates between IED locations and the actual regions underlying seizure initiation in focal epilepsy. Rats have been commonly used in preclinical studies of epilepsy1; hence, there exist a large variety of models for focal epilepsy in this particular species. However, it is challenging to record multichannel EEG and to perform brain source imaging in such a small animal. To overcome this issue, we combine a patented-technology to obtain 32-channel EEG recordings from rodents2 and an MRI probabilistic atlas for brain anatomical structures in Wistar rats to perform brain source imaging. In this video, we introduce the procedures to acquire multichannel EEG from Wistar rats with focal cortical dysplasia, and describe the steps both to define the volume conductor model from the MRI atlas and to uniquely determine the IEDs. Finally, we validate the whole methodology by obtaining brain source images of IEDs and compare them with those obtained at different time frames during the seizure onset.

حالما يتم الانتهاء من جميع الإجراءات بشكل صحيح، مصادر المقدرة يمكن تصور في سطح الدماغ من نموذج ما قبل السريرية ويبين الشكل 5 المصادر المقدرة من معين واحد نوع فرعي من كعب (أعلى) وموجات حادة (القاع) من العبوات الناسفة. بالإضافة إلى ذلك، الشكل 6 يعرض كيف يتغير توزيع مصدر في أطر زمنية متتابعة خلال إنشاء النوبة. هذه النتائج تدعم قدرة المنهجيات المقترحة لتسجيل عالية الدقة EEG على الفئران يعانون من الصرع البؤري وإجراء تحليل المصدر باستخدام EEG المسجلة. <img alt="البصري 6" src="/files/ftp_upload/52700/52700fig5.jpg" /> الرقم 5. المقدرة مواقع المصدر الدماغ من العبوات الناسفة فيما يتعلق مجموعات مختلفة في كعب (أعلى) وموجات حادة (القاع). (A) السلاسل الزمنية، (B) تضاريس EEG، و (C) القشرية الحالية الحامضالمجال الاقتصادي الموحد. يتم تنفيذ تقييم في وقت محدد ملحوظ مع خط عمودي الأحمر في (A). <a href="https://www.jove.com/files/ftp_upload/52700/52700fig5highres.jpg" target="_blank">الرجاء النقر هنا لمشاهدة نسخة أكبر من هذا الرقم.</a> <img alt="البصري 6" src="/files/ftp_upload/52700/52700fig6.jpg" /> الرقم 6. مصادر الدماغ المقدرة خلال النوبة. وتتميز اللحظات الوقت الذي خطوط عمودية حمراء. <a href="https://www.jove.com/files/ftp_upload/52700/52700fig6highres.jpg" target="_blank">الرجاء النقر هنا لمشاهدة نسخة أكبر من هذا الرقم.</a>

Watch this Scientific Journal Video about Brain Source Imaging in Preclinical Rat Models of Focal Epilepsy using High-Resolution EEG Recordings at JoVE.com

Brain Source Imaging in Preclinical Rat Models of Focal Epilepsy using High-Resolution EEG Recordings

This video introduces the preparation, recording, and source analysis procedures of high-resolution EEG on sedated rats with a particular preclinical model of focal epilepsy under noninvasive conditions.

الدماغ التصوير المصدر في ما قبل السريرية الفئران نماذج من الاتصال الصرع باستخدام عالية الدقة EEG تسجيلات

Electroencephalogram (EEG) has been traditionally used to determine which brain regions are the most likely candidates for resection in patients with ...

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Research

JoVE Journal

Medicine

15.2K Views.  Florida International University. This video introduces the preparation, recording, and source analysis procedures of high-resolution EEG on sedated rats with a particular preclinical model of focal epilepsy under noninvasive conditions.

Video: Brain Source Imaging in Preclinical Rat Models of Focal Epilepsy using High-Resolution EEG Recordings

MRI-guided Disruption of the Blood-brain Barrier using Transcranial Focused Ultrasound in a Rat Model

Focused ultrasound (FUS) disruption of the blood-brain barrier (BBB) is an increasingly investigated technique for circumventing the BBB1-5. The BBB is a significant obstacle to pharmaceutical treatments of brain disorders as it limits the passage of molecules from the vasculature into the brain tissue to molecules less than approximately 500 Da in size6. FUS induced BBB disruption (BBBD) is temporary and reversible4 and has an advantage over chemical means of inducing BBBD by being highly localized. FUS induced BBBD provides a means for investigating the effects of a wide range of therapeutic agents on the brain, which would not otherwise be deliverable to the tissue in sufficient concentration. While a wide range of ultrasound parameters have proven successful at disrupting the BBB2,5,7, there are several critical steps in the experimental procedure to ensure successful disruption with accurate targeting. This protocol outlines how to achieve MRI-guided FUS induced BBBD in a rat model, with a focus on the critical animal preparation and microbubble handling steps of the experiment.

Microbubble-mediated focused ultrasound disruption of the blood-brain barrier (BBB) is a promising technique for non-invasive targeted drug delivery in the brain1-3. This protocol outlines the experimental procedure for MRI-guided transcranial BBB disruption in a rat model.

التصوير بالرنين المغناطيسي موجهة تعطيل حاجز الدم في الدماغ باستخدام الموجات فوق الصوتية المركزة عبر الجمجمة في نموذج الفئران

Focused ultrasound (FUS) disruption of the blood-brain barrier (BBB) is an increasingly investigated technique for circumventing the BBB1-5. The BBB is a ...

Segmentation and Measurement of Fat Volumes in Murine Obesity Models Using X-ray Computed Tomography

Obesity is associated with increased morbidity and mortality as well as reduced metrics in quality of life.1 Both environmental and genetic factors are associated with obesity, though the precise underlying mechanisms that contribute to the disease are currently being delineated.2,3 Several small animal models of obesity have been developed and are employed in a variety of studies.4 A critical component to these experiments involves the collection of regional and/or total animal fat content data under varied conditions.
Traditional experimental methods available for measuring fat content in small animal models of obesity include invasive (e.g. ex vivo measurement of fat deposits) and non-invasive (e.g. Dual Energy X-ray Absorptiometry (DEXA), or Magnetic Resonance (MR)) protocols, each of which presents relative trade-offs. Current invasive methods for measuring fat content may provide details for organ and region specific fat distribution, but sacrificing the subjects will preclude longitudinal assessments. Conversely, current non-invasive strategies provide limited details for organ and region specific fat distribution, but enable valuable longitudinal assessment. With the advent of dedicated small animal X-ray computed tomography (CT) systems and customized analytical procedures, both organ and region specific analysis of fat distribution and longitudinal profiling may be possible. Recent reports have validated the use of CT for in vivo longitudinal imaging of adiposity in living mice.5,6 Here we provide a modified method that allows for fat/total volume measurement, analysis and visualization utilizing the Carestream Molecular Imaging Albira CT system in conjunction with PMOD and Volview software packages.

Fat content analysis is routinely conducted in studies utilizing murine obesity models. Emerging methods in small animal CT imaging and analysis are providing for longitudinal detail rich fat content analysis. Here we detail step by step procedures for performing small animal CT imaging, analysis, and visualization.

تجزئة والقياس من وحدات تخزين الدهون في الفئران نماذج السمنة عن طريق الأشعة السينية التصوير المقطعي

Obesity is associated with increased morbidity and mortality as well as reduced metrics in quality of life.1 Both environmental and genetic factors are ...

A Novel High-resolution In vivo Imaging Technique to Study the Dynamic Response of Intracranial Structures to Tumor Growth and Therapeutics

We have successfully integrated previously established Intracranial window (ICW) technology 1-4 with intravital 2-photon confocal microscopy to develop a novel platform that allows for direct long-term visualization of tissue structure changes intracranially. Imaging at a single cell resolution in a real-time fashion provides supplementary dynamic information beyond that provided by standard end-point histological analysis, which looks solely at 'snap-shot' cross sections of tissue.
Establishing this intravital imaging technique in fluorescent chimeric mice, we are able to image four fluorescent channels simultaneously. By incorporating fluorescently labeled cells, such as GFP+ bone marrow, it is possible to track the fate of these cells studying their long-term migration, integration and differentiation within tissue. Further integration of a secondary reporter cell, such as an mCherry glioma tumor line, allows for characterization of cell:cell interactions. Structural changes in the tissue microenvironment can be highlighted through the addition of intra-vital dyes and antibodies, for example CD31 tagged antibodies and Dextran molecules.
Moreover, we describe the combination of our ICW imaging model with a small animal micro-irradiator that provides stereotactic irradiation, creating a platform through which the dynamic tissue changes that occur following the administration of ionizing irradiation can be assessed.
Current limitations of our model include penetrance of the microscope, which is limited to a depth of up to 900 &mu;m from the sub cortical surface, limiting imaging to the dorsal axis of the brain. The presence of the skull bone makes the ICW a more challenging technical procedure, compared to the more established and utilized chamber models currently used to study mammary tissue and fat pads 5-7. In addition, the ICW provides many challenges when optimizing the imaging.

A Novel High-resolution In vivo Imaging Technique to Study the Dynamic Response of Intracranial Structures to Tumor Growth and Therapeutics

We describe a novel in vivo imaging technique that couples fluorescent chimeric mice with intracranial windows and high-resolution 2-photon microscopy. This imaging platform aids studies of dynamic changes in brain tissue and microvasculature, at a single-cell level, following pathological insults and is adaptable to assess intracranial drug delivery and distribution.

رواية عالية الدقة<em&gt; في الجسم الحي</em&gt; تقنية التصوير لدراسة الاستجابة الديناميكية للمنشآت داخل القحف لنمو الورم والتداوي

We have successfully integrated previously established Intracranial window (ICW) technology 1-4 with intravital 2-photon confocal microscopy to develop a ...

MRI and PET in Mouse Models of Myocardial Infarction

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ideal model for testing novel therapeutic strategies.
In vivo magnetic resonance imaging (MRI) gives excellent views of the heart noninvasively with clear anatomical detail, which can be used for accurate functional assessment. Contrast agents can provide basic measures of tissue viability but these are nonspecific. Positron emission tomography (PET) is a complementary technique that is highly specific for molecular imaging, but lacks the anatomical detail of MRI. Used together, these techniques offer a sensitive, specific and quantitative tool for the assessment of the heart in disease and recovery following treatment.
In this paper we explain how these methods are carried out in mouse models of acute myocardial infarction. The procedures described here were designed for the assessment of putative protective drug treatments. We used MRI to measure systolic function and infarct size with late gadolinium enhancement, and PET with fluorodeoxyglucose (FDG) to assess metabolic function in the infarcted region. The paper focuses on practical aspects such as slice planning, accurate gating, drug delivery, segmentation of images, and multimodal coregistration. The methods presented here achieve good repeatability and accuracy maintaining a high throughput.

We describe how to perform MRI and PET imaging of the mouse heart. The protocol is tailored to assess treatment efficacy in models of myocardial infarction and heart failure.

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ...

Multi-electrode Array Recordings of Human Epileptic Postoperative Cortical Tissue

Epilepsy, affecting about 1% of the population, comprises a group of neurological disorders characterized by the periodic occurrence of seizures, which disrupt normal brain function. Despite treatment with currently available antiepileptic drugs targeting neuronal functions, one third of patients with epilepsy are pharmacoresistant. In this condition, surgical resection of the brain area generating seizures remains the only alternative treatment. Studying human epileptic tissues has contributed to understand new epileptogenic mechanisms during the last 10 years. Indeed, these tissues generate spontaneous interictal epileptic discharges as well as pharmacologically-induced ictal events which can be recorded with classical electrophysiology techniques. Remarkably, multi-electrode arrays (MEAs), which are microfabricated devices embedding an array of spatially arranged microelectrodes, provide the unique opportunity to simultaneously stimulate and record field potentials, as well as action potentials of multiple neurons from different areas of the tissue. Thus MEAs recordings offer an excellent approach to study the spatio-temporal patterns of spontaneous interictal and evoked seizure-like events and the mechanisms underlying seizure onset and propagation. Here we describe how to prepare human cortical slices from surgically resected tissue and to record with MEAs interictal and ictal-like events ex vivo.

We here describe how to perform multi-electrode array recordings of human epileptic cortical tissue. Epileptic tissue resection, slice preparation and multi-electrode array recordings of interictal and ictal events are demonstrated in detail.

متعدد القطب تسجيلات صفيف من داء الصرع بعد الجراحة القشرية الأنسجة البشرية

Epilepsy, affecting about 1% of the population, comprises a group of neurological disorders characterized by the periodic occurrence of seizures, which ...

Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images

Cerebral microinfarcts are frequent findings in the post-mortem human brain, and are related to cognitive decline and dementia. Due to their small sizes it is challenging to study them on clinical MRI scans. It was recently demonstrated that cortical microinfarcts can be depicted with MRI scanners using high magnetic field strengths (7T). Based on this experience, a proportion of these lesions is also visible on lower resolution 3T MRI. These findings were corroborated with ex vivo imaging of post-mortem human brain tissue, accompanied by histopathological verification of possible cortical microinfarcts.
Here an ex vivo imaging protocol is presented, for the purpose of validating MR observed cerebral microvascular pathology with histological evaluation. Furthermore, guidelines are provided for the assessment of cortical microinfarcts on both in vivo 7T and 3T MR images. These guidelines provide researchers with a tool to rate cortical microinfarcts on in vivo images of larger patient samples, to further unravel their clinical relevance in cognitive decline and dementia, and establish these lesions as a novel biomarker of cerebral small vessel disease.

A high resolution ex vivo 7T MR imaging protocol is presented, to perform MR-guided histopathological validation of microvascular pathology in post-mortem human brain tissue. Furthermore, guidelines are provided for the assessment of cortical microinfarcts on in vivo 7T as well as 3T MR images.

تقييم القشرية الدماغية Microinfarcts على ارتفاع القرار MR الصور

Cerebral microinfarcts are frequent findings in the post-mortem human brain, and are related to cognitive decline and dementia. Due to their small sizes ...

A Multimodal Imaging- and Stimulation-based Method of Evaluating Connectivity-related Brain Excitability in Patients with Epilepsy

Resting-state functional connectivity MRI (rs-fcMRI) is a technique that identifies connectivity between different brain regions based on correlations over time in the blood-oxygenation level dependent signal. rs-fcMRI has been applied extensively to identify abnormalities in brain connectivity in different neurologic and psychiatric diseases. However, the relationship among rs-fcMRI connectivity abnormalities, brain electrophysiology and disease state is unknown, in part because the causal significance of alterations in functional connectivity in disease pathophysiology has not been established. Transcranial Magnetic Stimulation (TMS) is a technique that uses electromagnetic induction to noninvasively produce focal changes in cortical activity. When combined with electroencephalography (EEG), TMS can be used to assess the brain's response to external perturbations. Here we provide a protocol for combining rs-fcMRI, TMS and EEG to assess the physiologic significance of alterations in functional connectivity in patients with neuropsychiatric disease. We provide representative results from a previously published study in which rs-fcMRI was used to identify regions with abnormal connectivity in patients with epilepsy due to a malformation of cortical development, periventricular nodular heterotopia (PNH). Stimulation in patients with epilepsy resulted in abnormal TMS-evoked EEG activity relative to stimulation of the same sites in matched healthy control patients, with an abnormal increase in the late component of the TMS-evoked potential, consistent with cortical hyperexcitability. This abnormality was specific to regions with abnormal resting-state functional connectivity. Electrical source analysis in a subject with previously recorded seizures demonstrated that the origin of the abnormal TMS-evoked activity co-localized with the seizure-onset zone, suggesting the presence of an epileptogenic circuit. These results demonstrate how rs-fcMRI, TMS and EEG can be utilized together to identify and understand the physiological significance of abnormal brain connectivity in human diseases.

Resting-state functional-connectivity MRI has identified abnormalities in patients with a wide range of neuropsychiatric disorders, including epilepsy due to malformations of cortical development. Transcranial Magnetic Stimulation in combination with EEG can demonstrate that patients with epilepsy have cortical hyperexcitability in regions with abnormal connectivity.

والمتعدد الوسائط Imaging- والقائم على تحفيز أسلوب تقييم الربط المتعلقة الدماغ استثارة في المرضى الذين يعانون من الصرع

Resting-state functional connectivity MRI (rs-fcMRI) is a technique that identifies connectivity between different brain regions based on correlations ...

Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control seizures. However, a significant minority of patients continues to exhibit post-operative seizures, even in those cases in which the suspected source of seizures has been correctly localized and resected. The protocol presented here combines a clinical procedure routinely employed during the pre-operative evaluation of temporal lobe epilepsy (TLE) patients with a novel technique for network analysis. The method allows for the evaluation of the temporal evolution of mesial network parameters. The bilateral insertion of foramen ovale electrodes (FOE) into the ambient cistern simultaneously records electrocortical activity at several mesial areas in the temporal lobe. Furthermore, network methodology applied to the recorded time series tracks the temporal evolution of the mesial networks both interictally and during the seizures. In this way, the presented protocol offers a unique way to visualize and quantify measures that considers the relationships between several mesial areas instead of a single area.

This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale recordings.

تحليل شبكة الثقبة البيضوية الكهربائي تسجيلات في الفص الصدغي الصرع المرضى المقاوم للأدوية

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control ...

The Pilocarpine Model of Temporal Lobe Epilepsy and EEG Monitoring Using Radiotelemetry System in Mice

Temporal lobe epilepsy (TLE) is a common neurological disorder in adulthood. For translational studies of chronic epilepsy, pilocarpine-induced status epilepticus (SE) is frequently selected to recapitulate spontaneous recurrent seizures (SRS). Here we present a protocol of SE induction by intraperitoneal (i.p.) injection of pilocarpine and monitoring of chronic recurring seizures in live animals using a wireless telemetry video and electroencephalogram (EEG) system. We demonstrated notable behavioral changes that need attention after pilocarpine injection and their correlation with hippocampal neuronal loss at 7 days and 6 weeks post-pilocarpine. We also describe the experimental procedures of electrode implantation for video and EEG recording, and analysis of the frequency and duration of chronic recurrent seizures. Finally, we discuss the possible reasons why the expected results are not achieved in each case. This provides a basic overview of modeling chronic epilepsy in mice and guidelines for troubleshooting. We believe this protocol can serve as a baseline for suitable models of chronic epilepsy and epileptogenesis.

This manuscript describes a method of inducing status epilepticus by systemic pilocarpine injection and of monitoring spontaneous recurrent seizures in live animals using a wireless telemetry video and electroencephalogram system. This protocol can be utilized for studying the pathophysiologic mechanisms of chronic epilepsy, epileptogenesis, and acute seizures.

نموذج Pilocarpine صرع الفص الصدغي ورصد EEG باستخدام نظام راديوتيليميتري في الفئران

Temporal lobe epilepsy (TLE) is a common neurological disorder in adulthood. For translational studies of chronic epilepsy, pilocarpine-induced status ...

High-Resolution Three-Dimensional Imaging of the Footpad Vasculature in a Murine Hindlimb Gangrene Model

Peripheral arterial disease (PAD) is a significant cause of morbidity resulting from chronic exposure to atherosclerotic risk factors. Patients suffering from its most severe form, chronic limb-threatening ischemia (CLTI), face substantial impairments to daily living, including chronic pain, limited walking distance without pain, and nonhealing wounds. Preclinical models have been developed in various animals to study PAD, but mouse hindlimb ischemia remains the most widely used. There can be significant variation in response to ischemic insult in these models depending on the mouse strain used and the site, number, and means of arterial disruption. This protocol describes a unique method combining femoral artery and vein electrocoagulation with the administration of a nitric oxide synthase (NOS) inhibitor to reliably induce footpad gangrene in Friend Virus B (FVB) mice that resembles the tissue loss of CLTI. While traditional means of assessing reperfusion such as laser Doppler perfusion imaging (LDPI) are still recommended, intracardiac perfusion of the lipophilic dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) is used to label the vasculature. Subsequent whole-mount confocal laser scanning microscopy allows for high-resolution, three-dimensional (3D) reconstruction of footpad vascular networks that complements traditional means of assessing reperfusion in hindlimb ischemia models.

The present protocol describes a unique, clinically relevant model of peripheral arterial disease that combines femoral artery and vein electrocoagulation with the administration of a nitric oxide synthase inhibitor to induce hindlimb gangrene in FVB mice. Intracardiac DiI perfusion is then used for high-resolution, three-dimensional imaging of the footpad vasculature.

تصوير ثلاثي الأبعاد عالي الدقة للأوعية الدموية لوسادة القدم في نموذج غرغرينا Murine Hindlimb

Peripheral arterial disease (PAD) is a significant cause of morbidity resulting from chronic exposure to atherosclerotic risk factors. Patients suffering ...