Name: in vivo electrophysiological measurement of the rat ulnar nerve with axonal excitability testing
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Description: Watch this Scientific Journal Video about In Vivo Electrophysiological Measurement of the Rat Ulnar Nerve with Axonal Excitability Testing at JoVE.com

プロジェクトは、ルンドベック財団、ノボ ノルディスク財団、デンマークの医学研究評議会、Ludvig とサラ Elsass 財団、イテ ・神経研究財団とカイ Dahlboms 財団によって支えられました。R.A 国立保健医療研究評議会のオーストラリア (#1091006) の初期のキャリア ドクトラル交わりに支えられて

ここで説明したすべての実験手順は動物愛護及びシドニー ニューサウス ウェールズ大学の倫理委員会に適合し、国民の健康と動物実験のためのオーストラリアの規則の医学研究評議会 (NHMRC) に従い行った。
1. 実験のセットアップ
注: この手順では 12 週齢、女性のロング ・ ラットが使用されました。
<ol><li>分 O2流量あたり 4% イソフルランと 1 L を用いた誘導室でラットを麻酔します。立ち直り反射テストにより十分な麻酔を確認し、誘導室から動物を削除する前にその不在を確認します。様々 な麻酔薬が神経興奮性10差動効果を持っていることに注意してください。</li>
	<li>安全に鼻の円錐形のアタッチメントで動物の鼻を配置および分 O2流量当たり 2.5% イソフルランと 1 L の維持投与量を提供します。</li>
	<li>動物の足の指をつまんで、目に優しく触れによってペダル撤退および角膜反射の両方をチェックするには、適切な麻酔を確認します。 注: 麻酔、乾燥を防ぐための目に獣医軟膏のアプリケーションは推奨されるが、必須ではありません、通常動物あたり 30 分を要します。</li>
	<li>フィードバック制御を用いた暖房のマットの直腸体温計プローブ使用で 37 ° C でラットの体温を維持します。40 の ° C より高い温度で発生する皮膚損傷を防ぐために暖房のマットと統合的な温度センサーを設定します。 注: お勧め (心拍数、酸素飽和度、体温、呼吸数) の監視と記録の生理対策に動物の生理学的モニタリング システムを使ってすべての 10 秒。周辺の温度はコア温度11 (図 1) のそれよりも寒いことがあるので、最適なレコーディング手順は下肢の温度のローカル測定を含める必要があります。</li>
	<li>防腐剤の手袋を着用し、常にプロシージャ全体で病原体フリーの環境を維持するために 70% エタノールで洗浄されている楽器を使用します。</li>
</ol>2 電気生理学的設定
<ol><li>この手順で低インピー ダンス プラチナ脳波 (EEG) 針電極を使用します。</li>
	<li>研究筋と 4 桁の背側面を介して参照電極を記録電極 (図 1; で示された紫色) を挿入することによって記録針電極を準備 (図 1で示されている;オレンジ) 複合筋活動電位 (概念地図) を記録します。</li>
	<li>刺激電極 (図 1; 緑で示されている) と前腕の優れた側面に皮膚を通して接地電極を配置します。筋肉組織を避けるために電極を挿入するときに注意します。</li>
	<li>経皮的刺激的な針の電極を陰極 (図 1; のラベル青) を挿入することによって準備約 4 mm、肘への遠位肘トンネルします。挿入 (図 1; のラベル付き赤) 陽極腋窩領域の皮膚を通して近位約 1 cm。</li>
</ol><img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56102/56102fig1.jpg"> 図 1: ラットの前肢の針電極配置の図。陰極 (青) が約 4 mm 肘肘部管の遠位に挿入され、陽極 (赤色) を挿入腋窩領域の皮膚を通して近位約 1 cm。刺激電極を記録と前腕の優れた側面に皮膚を通して地面針電極 (緑) が挿入されます。研究筋と 4番目の桁の背側面を通して記録 (紫) と参照 (オレンジ) 針電極が挿入されます。温度プローブ (グレイ) は、母指球筋の優れた側面に配置されます。<a href="//cloudflare.jove.com/files/ftp_upload/56102/56102fig1large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
3. 軸索興奮性の手順
<ol><li>齧歯動物の運動神経による半自動 TRONDNF プロトコルを実行、コンピューター制御された軸索興奮性プログラムは一定の電流刺激装置とアンプにリンク (材料の表を参照してください)。50/60 Hz ノイズ除去を使用して余分な 50 Hz 電気的なノイズを削除します。<ol>
<li>同時に CMAP 形態を可視化し、1 を適用することによって研究筋から CMAP を記録電極針で尺骨神経に ms 矩形波パルス。<ol>
<li>最適な録音を達成するため、振幅が一定の最適な相性の応答曲線になるまで慎重に角度や陰極の位置を調整するには、(図 2 a.) を達成しました。最適な位置を決定すると、一度変え電極ホルダーに陰極を安定させます。 注: 自動的に使用されるソフトウェア、下記テスト刺激を提供し増加またはしきい値を達成するために必要な電流を減少します。</li>
		</ol>
</li>
		<li>1 の刺激強度を段階的に増加して刺激-反応曲線を記録 1 ms インパルス mA 最大応答が達成されるまで。 注: 図 2 b および 2 C の紫と緑の線はそれぞれ刺激強度と自動化されたシステムの増分増加を表します。追跡のしきい値のターゲットの振幅は刺激-反応曲線の急勾配法面の面積に対応する最大振幅の 40% に自動的に設定されます。「しきい値」に変更 (40% を引き出すために必要な刺激すなわち CMAP) による各種テスト刺激はの変数プロトコルの残りを得た。</li>
		<li>しきい値 electrotonus (TE) を含む複数の軸索興奮性パラメーターを記録電流しきい値 (私/V) 関係回復サイクル (RC) 参照に従って12。 注: コンピューター制御軸索興奮性プログラム評価閾値 (TE) を 100 ms の脱分極と過分極電流、サブスレッショルド電流制御しきい値の ± 40% と ± 20% で設定されています。後脱分極と過分極電流しきい値の変更は、自動的に偏光現在後現在偏光 100 ms と 12 ポイントの間に 14 の時点で記録されます。間接的しきい値 electrotonus 節間のコンダクタンスを評価、膜電位のマーカーです。私 V 関係が交互に +50 から強度 200 ms サブスレッショルド エアコン電流評価/-100% 10% ごとの増減制御しきい値の %。I/V の関係とは異なり、TE に電流が期間の長い、偏波の強度は 50 から変更徐々 に-100% % としきい値の変更は各強度 1 で評価は偏光の現在がなくなった後 ms。I/V の関係軸索1の整流特性への洞察力を提供します。対パルス パラダイム、初期の激刺激が適用されるこのパラメーター結節で発生するイベントの明確に定義された一連のテスト 200 さんに、2.5 ms から特定の間隔でテスト刺激のシリーズに続くと RC を評価します。激刺激軸索の領域。これらのイベントは、その後の応答を引き出すことが難しく、不応期と相対不応期1定量化している電位依存性の Na+チャネルの不活性化を含みます。これは節間と高速カリウム チャネル、superexcitability によって定量化による高められた興奮性の期間の充電が続きます。最後に、ゆっくり活性化カリウム チャネルは、subexcitability として定量化の減らされた興奮の後期を仲介します。</li>
	</ol>
</li>
</ol><img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56102/56102fig2.jpg"> 図 2: 軸索興奮性テストから Raw データパネル A は、尺骨神経への刺激の増分増加後 abiphasic CMAP 応答曲線を示します。パネル B と C は、それぞれ刺激強度 (mA) と CMAP (mV) の振幅を表します。B と C の緑のコンポーネントは、刺激強度の自動増分減少と追跡のしきい値に必要な CMAP で関連付けられているシグモイド形減少を示しています。
4. ポスト電気生理学手続き
<ol><li>それは胸骨の横臥を維持するために十分な意識を取り戻したまで別々 のケージにラットを転送します。動物は、無人と他の動物の会社で、それは完全に麻酔から回復するまでには、放置しないでください。ラットは完全に麻酔から回復、かつては、その元のケージに戻って転送します。</li>
	<li>調査の完了時に、バルビツール酸塩 (例えば lethabarb) の動物、例えば致命的な腹腔内注入の痛みを伴わないラットを安楽死させます。</li>
</ol>

<ol>
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著者が明らかに何もありません。

記載された手順を示します、シンプルで信頼性の高い、低侵襲技術ができる生物物理物性評価および軸索の膜電位時間の短い期間でです。神経の露出を必要とする他のより侵襲的な技術と比較して軸索興奮性のテスト法誘導の生理状態を維持する体内の評価ができ最小限の組織損傷、興味の神経、繰り返し測定が可能します。
確実に一貫性のある結果が、対処す?...

電気生理学的技術の使用は神経疾患における末梢神経機能の生体内で調査のために不可欠なツールです。従来神経伝導メソッドは、潜時や振幅運動の活動電位を記録する激刺激を利用します。これらの技術は、繊維の実施数と最速の線維の伝導速度したがって有用な情報を提供します。貴重な相補的なツールは、軸索興奮性のテストのことです。この手法は、イオン チャネル、エネルギー依存性ポンプ、イオン交換プロセス、膜電位の活性などの末梢神経の生物物理学的プロパティを直接評価する洗練された電気生理学的刺激のパターンを使用してください。1。
病態生理学的プロセスと様々 な脳神経疾患の治療介入の効果を検討する臨床場面における軸索興奮性テストを利用して一般的。重要なは、軸索興奮性対策2静脈内の免疫グロブリン (IVIg) 療法など末梢神経機能に影響を与える治療に敏感である化学療法3カルシニューリン阻害剤 (CNI) 治療4. 臨床研究がこれらの研究は、重要な洞察を提供している、初期の病の特徴と治療の新しい選択肢5の調査を排除する頻繁。したがって、神経疾患の動物モデルでこれらのメソッドの使用は最近トラクション6,7,8,9を得ています。確かに、これらのメソッドは、トランスレーショナル ・ リサーチを推進したがって、これらの疾患に関連付けられている特定の神経の興奮性の変化を理解する機会を提供します。
ここで説明する手順は、そのままのラットの尺骨神経にレコードの軸索興奮性対策にシンプルで信頼性の高い方法です。

<table><tbody><tr><td>QTracS Program</td><td>Digitimer Ltd.</td><td></td><td>Axonal excitability program</td></tr><tr><td>AM-Systems 2200, Analog Stimulus Isolator, 2200V/50Hz</td><td>SDR Scientific</td><td>850005</td><td>Stimulator</td></tr><tr><td>High Performance AC Amplifier Model LP511</td><td>Grass Technologies</td><td></td><td>Amplifier</td></tr><tr><td>Humbug 50/60Hz Noise eliminator</td><td>Quest Scientific Instruments</td><td>726310</td><td>Noise eliminator</td></tr><tr><td>Low Impedance Platinum Monopolar Subdermal Needle Electrodes</td><td>Grass Technologies</td><td>F-E2-24</td><td>Recording electrodes, 10 mm length, 30 gauge</td></tr><tr><td>Low Impedance Platinum Electroencephalography Needle Electrodes</td><td>Cephalon</td><td>9013L0702</td><td>Stimulating electrodes, 10 mm length, 30 gauge</td></tr><tr><td>Multifunction I/O Device Model USB-6341</td><td>National Instruments</td><td></td><td>Multifunction input/output device</td></tr><tr><td>Iron Base Plate IP</td><td>Narishige Scientific Instrument Laboratory</td><td></td><td>Used for holding stimulating needle electrode in place</td></tr><tr><td>Rotating X-block X-4</td><td>Narishige Scientific Instrument Laboratory</td><td></td><td>Used for holding stimulating needle electrode in place</td></tr><tr><td>Magnetic Stand GJ-8</td><td>Narishige Scientific Instrument Laboratory</td><td></td><td>Used for holding stimulating needle electrode in place</td></tr><tr><td>Micromanipulator M-3333</td><td>Narishige Scientific Instrument Laboratory</td><td></td><td>Used for holding stimulating needle electrode in place</td></tr></tbody></table>

in vivo electrophysiological measurement of the rat ulnar nerve with axonal excitability testing

電気生理学末梢神経機能のin vivoの客観的な評価ができます。潜時や振幅検出慢性軸索損失と脱髄、それぞれなど伝統的な神経伝導を測定します。イオン チャンネル、ポンプ、急性機能に関連し、退化的なイベントの前にことがあります交換のアクティビティに関する情報を提供することによってこれらの措置により軸索興奮性技術"しきい値を追跡"を展開します。そのため、神経疾患の動物モデルにおける軸索興奮性の使用新しい治療的介入を評価するために有用な生体内測定があります。ここでラットの尺骨神経で運動軸索興奮性技術の複数の措置の実験装置について述べる。
動物はイソフルラン麻酔、麻酔の定数と十分な深さを確保するため慎重に監視します。体温、呼吸、心拍数、血液中の酸素の飽和を継続的に監視します。軸索興奮性の研究は、尺骨神経と前肢足の研究筋から記録の経皮的刺激を使用して実行されます。正しい電極配置、刺激強度の増加とともに振幅の増加明確な複合筋活動電位が記録されます。自動化されたプログラムを利用する一連の次の順序で 5 特定の興奮性対策を生成する電気パルスを提供する: 刺激応答性状、強度期間時定数、しきい値 electrotonus、電流しきい値関係と回復のサイクル。
ここで表示されるデータは、これらの措置を繰り返し同じ日に評価すると左と右尺骨神経との間の類似性を示すを示します。この設定にこれらの手法の制限は、投与量と麻酔時間の効果です。慎重に監視し、これらの変数の記録は、解析時に考慮のため行わなければなりません。

ラットの尺骨神経の電気生理学的措置は、この議定書が得られました。図 3は、12 週齢雌長いエバンス ラットの左尺骨神経から記録担当者を示します。複合筋活動電位は、同時にアクティブになっている繊維を導電性の数に関連します。激ピーク応答 (mV) (図 3 a) は、(図 2 b) 応答の変化がないまで刺?...

Watch this Scientific Journal Video about In Vivo Electrophysiological Measurement of the Rat Ulnar Nerve with Axonal Excitability Testing at JoVE.com

In Vivo Electrophysiological Measurement of the Rat Ulnar Nerve with Axonal Excitability Testing

生体内で軸索興奮性のテストでラットの尺骨神経の電気生理学的測定

軸索興奮性のテクニックは、病態と不可逆的な変性イベントの前に生体の変化を調べるための強力なツールを提供します。この原稿は、麻酔下ラットの尺骨神経のこれらのテクニックの使用方法を示します。

Electrophysiology enables the objective assessment of peripheral nerve function in vivo. Traditional nerve conduction measures such as amplitude and ...

in-vivo-electrophysiological-measurement-rat-ulnar-nerve-with-axonal

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

In Vivo Electrophysiological Measurement of the Rat Ulnar Nerve with Axonal Excitability Testing

9.1K ビュー.  University of New South Wales. 軸索興奮性のテクニックは、病態と不可逆的な変性イベントの前に生体の変化を調べるための強力なツールを提供します。この原稿は、麻酔下ラットの尺骨神経のこれらのテクニックの使用方法を示します。

ビデオ: In Vivo Electrophysiological Measurement of the Rat Ulnar Nerve with Axonal Excitability Testing

Nerve Excitability Assessment in Chemotherapy-induced Neurotoxicity

Chemotherapy-induced neurotoxicity is a serious consequence of cancer treatment, which occurs with some of the most commonly used chemotherapies1,2. Chemotherapy-induced peripheral neuropathy produces symptoms of numbness and paraesthesia in the limbs and may progress to difficulties with fine motor skills and walking, leading to functional impairment. In addition to producing troubling symptoms, chemotherapy-induced neuropathy may limit treatment success leading to dose reduction or early cessation of treatment. Neuropathic symptoms may persist long-term, leaving permanent nerve damage in patients with an otherwise good prognosis3. As chemotherapy is utilised more often as a preventative measure, and survival rates increase, the importance of long-lasting and significant neurotoxicity will increase.
There are no established neuroprotective or treatment options and a lack of sensitive assessment methods. Appropriate assessment of neurotoxicity will be critical as a prognostic factor and as suitable endpoints for future trials of neuroprotective agents. Current methods to assess the severity of chemotherapy-induced neuropathy utilise clinician-based grading scales which have been demonstrated to lack sensitivity to change and inter-observer objectivity4. Conventional nerve conduction studies provide information about compound action potential amplitude and conduction velocity, which are relatively non-specific measures and do not provide insight into ion channel function or resting membrane potential. Accordingly, prior studies have demonstrated that conventional nerve conduction studies are not sensitive to early change in chemotherapy-induced neurotoxicity4-6. In comparison, nerve excitability studies utilize threshold tracking techniques which have been developed to enable assessment of ion channels, pumps and exchangers in vivo in large myelinated human axons7-9.
Nerve excitability techniques have been established as a tool to examine the development and severity of chemotherapy-induced neurotoxicity10-13. Comprising a number of excitability parameters, nerve excitability studies can be used to assess acute neurotoxicity arising immediately following infusion and the development of chronic, cumulative neurotoxicity. Nerve excitability techniques are feasible in the clinical setting, with each test requiring only 5 -10 minutes to complete. Nerve excitability equipment is readily commercially available, and a portable system has been devised so that patients can be tested in situ in the infusion centre setting. In addition, these techniques can be adapted for use in multiple chemotherapies.
In patients treated with the chemotherapy oxaliplatin, primarily utilised for colorectal cancer, nerve excitability techniques provide a method to identify patients at-risk for neurotoxicity prior to the onset of chronic neuropathy. Nerve excitability studies have revealed the development of an acute Na+ channelopathy in motor and sensory axons10-13. Importantly, patients who demonstrated changes in excitability in early treatment were subsequently more likely to develop moderate to severe neurotoxicity11. However, across treatment, striking longitudinal changes were identified only in sensory axons which were able to predict clinical neurological outcome in 80% of patients10. These changes demonstrated a different pattern to those seen acutely following oxaliplatin infusion, and most likely reflect the development of significant axonal damage and membrane potential change in sensory nerves which develops longitudinally during oxaliplatin treatment10. Significant abnormalities developed during early treatment, prior to any reduction in conventional measures of nerve function, suggesting that excitability parameters may provide a sensitive biomarker.

This abstract describes a novel method to assess the development of neurotoxicity in patients receiving chemotherapy treatment. While conventional assessment methods are limited in their ability to detect early changes in nerve function, nerve excitability techniques provide early identification of patients at risk of severe neurotoxicity and insight into pathophysiology.

化学療法誘発性神経の神経興奮性の評価

Chemotherapy-induced neurotoxicity is a serious consequence of cancer treatment, which occurs with some of the most commonly used chemotherapies1,2. ...

神経科学

In Vivo Electrophysiological Measurements on Mouse Sciatic Nerves

Electrophysiological studies allow a rational classification of various neuromuscular diseases and are of help, together with neuropathological techniques, in the understanding of the underlying pathophysiology1. Here we describe a method to perform electrophysiological studies on mouse sciatic nerves in vivo.
The animals are anesthetized with isoflurane in order to ensure analgesia for the tested mice and undisturbed working environment during the measurements that take about 30 min/animal. A constant body temperature of 37 &#176;C is maintained by a heating plate and continuously measured by a rectal thermo probe2. Additionally, an electrocardiogram (ECG) is routinely recorded during the measurements in order to continuously monitor the physiological state of the investigated animals.
Electrophysiological recordings are performed on the sciatic nerve, the largest nerve of the peripheral nervous system (PNS), supplying the mouse hind limb with both motoric and sensory fiber tracts. In our protocol, sciatic nerves remain in situ and therefore do not have to be extracted or exposed, allowing measurements without any adverse nerve irritations along with actual recordings. Using appropriate needle electrodes3 we perform both proximal and distal nerve stimulations, registering the transmitted potentials with sensing electrodes at gastrocnemius muscles. After data processing, reliable and highly consistent values for the nerve conduction velocity (NCV) and the compound motor action potential (CMAP), the key parameters for quantification of gross peripheral nerve functioning, can be achieved.

In Vivo Electrophysiological Measurements on Mouse Sciatic Nerves

Measurements of nerve conduction properties in vivo exemplify a powerful tool to characterize various animal models of neuromuscular diseases. Here, we present an easy and reliable protocol by which electrophysiological analysis on sciatic nerves of anesthetized mice can be performed.

マウス坐骨神経に生体内電気生理学的測定値の

Electrophysiological studies allow a rational classification of various neuromuscular diseases and are of help, together with neuropathological ...

Measuring Neuromuscular Junction Functionality

Neuromuscular junction (NMJ) functionality plays a pivotal role when studying diseases in which the communication between motor neuron and muscle is impaired, such as aging and amyotrophic lateral sclerosis (ALS). Here we describe an experimental protocol that can be used to measure NMJ functionality by combining two types of electrical stimulation: direct muscle membrane stimulation and the stimulation through the nerve. The comparison of the muscle response to these two different stimulations can help to define, at the functional level, potential alterations in the NMJ that lead to functional decline in muscle.
Ex vivo preparations are suited to well-controlled studies. Here we describe an intensive protocol to measure several parameters of muscle and NMJ functionality for the soleus-sciatic nerve preparation and for the diaphragm-phrenic nerve preparation. The protocol lasts approximately 60 min and is conducted uninterruptedly by means of a custom-made software that measures the twitch kinetics properties, the force-frequency relationship for both muscle and nerve stimulations, and two parameters specific to NMJ functionality, i.e. neurotransmission failure and intratetanic fatigue. This methodology was used to detect damages in soleus and diaphragm muscle-nerve preparations by using SOD1G93A transgenic mouse, an experimental model of ALS that ubiquitously overexpresses the mutant antioxidant enzyme superoxide dismutase 1 (SOD1).

A functional assessment of the neuromuscular junction (NMJ) can provide essential information on the communication between muscle and nerve. Here we describe a protocol to comprehensively evaluate both the NMJ and muscle functionality using two different muscle-nerve preparations, i.e. soleus-sciatic and diaphragm-phrenic.

神経筋接合部機能を測定

Neuromuscular junction (NMJ) functionality plays a pivotal role when studying diseases in which the communication between motor neuron and muscle is ...

Establishing a Mouse Model of a Pure Small Fiber Neuropathy with the Ultrapotent Agonist of Transient Receptor Potential Vanilloid Type 1

Patients with diabetes mellitus (DM) or those experiencing the neurotoxic effects of chemotherapeutic agents may develop sensation disorders due to degeneration and injury of small-diameter sensory neurons, referred to as small fiber neuropathy. Present animal models of small fiber neuropathy affect both large- and small-diameter sensory fibers and thus create a neuropathology too complex to properly assess the effects of injured small-diameter sensory fibers. Therefore, it is necessary to develop an experimental model of pure small fiber neuropathy to adequately examine these issues. This protocol describes an experimental model of small fiber neuropathy specifically affecting small-diameter sensory nerves with resiniferatoxin (RTX), an ultrapotent agonist of transient receptor potential vanilloid type 1 (TRPV1), through a single dose of intraperitoneal injection, referred to as RTX neuropathy. This RTX neuropathy showed pathological manifestations and behavioral abnormalities that mimic the clinical characteristics of patients with small fiber neuropathy, including intraepidermal nerve fiber (IENF) degeneration, specifically injury in small-diameter neurons, and induction of thermal hypoalgesia and mechanical allodynia. This protocol tested three doses of RTX (200, 50, and 10 &#181;g/kg, respectively) and concluded that a critical dose of RTX (50 &#181;g/kg) is required for the development of typical small fiber neuropathy manifestations, and prepared a modified immunostaining procedure to investigate IENF degeneration and neuronal soma injury. The modified procedure is fast, systematic, and economic. Behavioral evaluation of neuropathic pain is critical to reveal the function of small-diameter sensory nerves. The evaluation of mechanical thresholds in experimental rodents is particularly challenging and this protocol describes a customized metal mesh that is suitable for this type of assessment in rodents. In summary, RTX neuropathy is a new and easily established experimental model to evaluate the molecular significance and intervention underlying neuropathic pain for the development of therapeutic agents.

This study establishes an experimental model of pure small fiber neuropathy with resiniferatoxin (RTX). A unique dose of RTX (50 &#181;g/kg) is optimal for developing a small fiber neuropathy model that mimics patient characteristics and could help investigate the nociceptive molecular significance underlying neuropathic pain.

一過性受容体電位バニロイド型 1 Ultrapotent アゴニストと純粋な小さな繊維の神経疾患のマウスモデルを確立します。

Patients with diabetes mellitus (DM) or those experiencing the neurotoxic effects of chemotherapeutic agents may develop sensation disorders due to ...

In Vivo Electrophysiological Measurement of Compound Muscle Action Potential from the Forelimbs in Mouse Models of Motor Neuron Degeneration

Assessing the functionality of the nerve axon provides detailed information on the progression of neuromuscular disorders. Electrophysiological recordings provide a sensitive approach to measure nerve conduction in humans and rodent models. To broaden the technical possibilities for electromyography in mice, the measurement of compound muscle action potentials (CMAPs) from the brachial plexus nerve in the forelimb using needle electrodes is described here. CMAP recordings after stimulating the sciatic nerve in hindlimbs have been previously described. The newly introduced method here allows for the evaluation of the nerve conductivity at an additional site, and thus provides a more profound overview of the neuromuscular functionality. The technique provides information on both the relative number of functional axons and the myelination level. Thereby, this method can be applied to assess both axonal diseases as well as demyelinating conditions. This minimally invasive method does not require extraction of the nerve and therefore it is suitable for repeated measurements for longitudinal follow-up in the same animal. Similar recordings are performed in clinical setups to emphasize the translational relevance of the method.

In Vivo Electrophysiological Measurement of Compound Muscle Action Potential from the Forelimbs in Mouse Models of Motor Neuron Degeneration

The measurement of nerve conduction is a useful tool to assess mouse models of neurodegeneration but it is frequently only applied to stimulate the sciatic nerve in hindlimbs. Here, we describe a technique to measure compound muscle action potential (CMAP) in vivo in the mouse forelimb muscles innervated by the brachial plexus.

生体内で運動ニューロンの変性症のマウスモデルの前肢からの複合筋活動電位の電気生理学的測定

Assessing the functionality of the nerve axon provides detailed information on the progression of neuromuscular disorders. Electrophysiological recordings ...

Use of In Vivo Single-fiber Recording and Intact Dorsal Root Ganglion with Attached Sciatic Nerve to Examine the Mechanism of Conduction Failure

Single-fiber recording has been a classical and effective electrophysiological technique over the last few decades because of its specific application for nerve fibers in the central and peripheral nervous systems. This method is particularly applicable to dorsal root ganglia (DRG), which are primary sensory neurons that exhibit a pseudo-unipolar structure of nervous processes. The patterns and features of the action potentials passed along axons are recordable in these neurons. The present study uses in vivo single-fiber recordings to observe the conduction failure of sciatic nerves in complete Freund&#8217;s adjuvant (CFA)-treated rats. As the underlying mechanism cannot be studied using in vivo single-fiber recordings, patch-clamp-recordings of DRG neurons are performed on preparations of intact DRG with the attached sciatic nerve. These recordings reveal a positive correlation between conduction failure and the rising slope of the after-hyperpolarization potential (AHP) of DRG neurons in CFA-treated animals. The protocol for in vivo single fiber-recordings allows the classification of nerve fibers via the measurement of conduction velocity and monitoring of abnormal conditions in nerve fibers in certain diseases. Intact DRG with attached peripheral nerve allows observation of the activity of DRG neurons in most physiological conditions. Conclusively, single-fiber recording combined with electrophysiological recording of intact DRGs is an effective method to examine the role of conduction failure during the analgesic process.

Single-fiber recording is an effective electrophysiological technique that is applicable to the central and peripheral nervous systems. Along with the preparation of intact DRG with the attached sciatic nerve, the mechanism of conduction failure is examined. Both protocols improve the understanding of the peripheral nervous system&#39;s relationship with pain.

インビボシングルファイバー記録と無傷の後部根神経を用いて伝導障害のメカニズムを調べる

Single-fiber recording has been a classical and effective electrophysiological technique over the last few decades because of its specific application for ...

Functional and Physiological Methods of Evaluating Median Nerve Regeneration in the Rat

The main goal of this investigation is to show how to create and repair different types of median nerve (MN) lesions in the rat. Moreover, different methods of simulating postoperative physiotherapy are presented. Multiple standardized strategies are used to assess motor and sensory recovery using an MN model of peripheral nerve lesion and repair, thus permitting easy comparison of the results. Several options are included for providing a postoperative physiotherapy-like environment to rats that have undergone MN injuries. Finally, the paper provides a method to evaluate the recovery of the MN using several noninvasive tests (i.e., grasping test, pin prick test, ladder rung walking test, rope climbing test, and walking track analysis), and physiological measurements (infrared thermography, electroneuromyography, flexion strength evaluation, and flexor carpi radialis muscle weight determination). Hence, this model seems particularly appropriate to replicate a clinical scenario, facilitating extrapolation of results to the human species.
Although the sciatic nerve is the most studied nerve in peripheral nerve research, analysis of the rat MN presents various advantages. For example, there is a reduced incidence of joint contractures and automutilation of the affected limb in MN lesion studies. Furthermore, the MN is not covered by muscle masses, making its dissection easier than that of the sciatic nerve. In addition, MN recovery is observed sooner, because the MN is shorter than the sciatic nerve. Also, the MN has a parallel path to the ulnar nerve in the arm. Hence, the ulnar nerve can be easily used as the nerve graft for repairing MN injuries. Finally, the MN in rats is located in the forelimb, akin to the human upper limb; in humans, the upper limb is the site of most peripheral nerve lesions.

Presented is a protocol to produce different types of median nerve (MN) lesions and repair in the rat. Additionally, the protocol shows how to evaluate the functional recovery of the nerve using several noninvasive behavioral tests and physiological measurements.

ラットの神経再生の中央値を評価する機能と生理学的方法

The main goal of this investigation is to show how to create and repair different types of median nerve (MN) lesions in the rat. Moreover, different ...

医学

Preparation of Rat Sciatic Nerve for Ex Vivo Neurophysiology

Ex vivo preparations enable the study of many neurophysiological processes in isolation from the rest of the body while preserving local tissue structure. This work describes the preparation of rat sciatic nerves for ex vivo neurophysiology, including buffer preparation, animal procedures, equipment setup and neurophysiological recording. This work provides an overview of the different types of experiments possible with this method. The outlined method aims to provide 6 h of stimulation and recording on extracted peripheral nerve tissue in tightly controlled conditions for optimal consistency in results. Results obtained using this method are A-fibre compound action potentials (CAP) with peak-to-peak amplitudes in the millivolt range over the entire duration of the experiment. CAP amplitudes and shapes are consistent and reliable, making them useful to test and compare new electrodes to existing models, or the effects of interventions on the tissue, such as the use of chemicals, surgical alterations, or neuromodulatory stimulation techniques. Both conventional commercially available cuff electrodes with platinum-iridium contacts and custom-made conductive elastomer electrodes were tested and gave similar results in terms of nerve stimulus strength-duration response.

Preparation of Rat Sciatic Nerve for Ex Vivo Neurophysiology

This protocol describes the preparation of rat whole sciatic nerve tissue for ex vivo electrophysiological stimulation and recording in an environmentally-regulated, two-compartment, perfused saline bath.

Ex Vivo神経生理学のためのラット坐骨神経の調製

Ex vivo preparations enable the study of many neurophysiological processes in isolation from the rest of the body while preserving local tissue structure. ...

Terminal H-reflex Measurements in Mice

The Hoffmann reflex (H-reflex), as an electrical analog to the stretch reflex, allows electrophysiological validation of the integrity of neural circuits after injuries such as spinal cord damage or stroke. An increase of the H-reflex response, together with symptoms like non-voluntary muscle contractions, pathologically augmented stretch reflex, and hypertonia in the corresponding muscle, is an indicator of post-stroke spasticity (PSS).
In contrast to rather nerve-unspecific transcutaneous measurements, here, we present a protocol to quantify the H-reflex directly at the ulnar and median nerves of the forepaw, which is applicable, with minor modifications, to the tibial and sciatic nerve of the hindpaw. Based on the direct stimulation and the adaptation to different nerves, the method represents a reliable and versatile tool to validate electrophysiological changes in spasticity-related disease models.

The clinical evaluation of spasticity based on the Hoffmann reflex (H-reflex) and using electrical stimulation of peripheral nerves is an established method. Here, we provide a protocol for a terminal and direct nerve stimulation for H-reflex quantification in the mouse forepaw.

マウスにおける終末H反射測定

The Hoffmann reflex (H-reflex), as an electrical analog to the stretch reflex, allows electrophysiological validation of the integrity of neural circuits ...

生物学

In Vivo Measurement of the Compound Muscle Action Potential in a Rat

Source: Wild, B. M., et al. <a href="https://appjove.unicartagenaproxy.elogim.com/v/56102">In Vivo Electrophysiological Measurement of the Rat Ulnar Nerve with Axonal Excitability Testing.</a> J. Vis. Exp. (2018)
This video demonstrates the procedure for recording compound muscle action potential (CMAP) in rats by applying electrical stimuli to the ulnar nerve, adjusting electrodes for optimal signal, and increasing stimulation to assess nerve functionality. This method enables the in vivo investigation of the peripheral nerve functions in neurological disorders.

ラットにおける化合物筋活動電位のin vivo測定

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. ...