Financial support from the Flanders Research Foundation FWO (contract n. 12C9112N to DL), the 7th Framework Programme of the European Commission (Marie Curie Network &#8220;C7&#8221;, contract n. 238214; ICT Future Emerging Technology &#8220;ENLIGHTENMENT&#8221; project, contract n. 306502), the Interuniversity Attraction Poles Program initiated by the Belgian Science Policy Office (contract n. IUAP-VII/20), and the University of Antwerp is kindly acknowledged.

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The authors have nothing to disclose.

このテキストリアルタイムの実施のための完全なプロトコルでは、閉ループ単一細胞電気実験はパッチクランプ法とLCGと呼ばれる最近開発されたソフトウェアツールボックスを使用して、説明しました。録音の品質を最適化するためには、記録の設定が正しく、接地シールドと振動しないことが重要である：これは、一緒に刺激プロトコルのセクション全体を自動化する可能性のある細胞へ?...

<html>近年、携帯電気生理学は、近代的な閉ループプロトコルに電圧および電流クランプ実験に用い、従来のオープンループパラダイムから進化してきました。最もよく知られている閉ループ技術は、おそらく神経細胞膜電位8を決定するために人工的な電位依存性イオンチャネルの合成注入を可能に動的クランプ6,7であり、非決定論的には、フリッカの影響の詳細な研究神経応答のダイナミクス9、ならびにシナプス背景活動10のようなvivo-で現実的なのin vitroでのレクリエーションのイオンチャネル。 提案されている他の閉ループパラダイムは、 インビトロ自立持続的活動の発生、及び応答は細胞機構を下にある神経細胞の興奮性を調査するために、4,12をクランプを研究するために、反応性クランプ11を含みます。 ontent &quot;&gt;ここでは、急性脳スライスで行われる全細胞パッチクランプ記録のコンテキストで閉ループ電気生理学の様々なプロトコルを適用することができる強力なフレームワークを記述している。我々は、パッチクランプ記録を用いて体細胞膜電圧を記録する方法を示しています若年ラットの体性感覚野からの錐体ニューロンでLCG、理論神経生物とNeuroengineeringの研究室で開発されたコマンドラインベースのソフトウェアツールボックスを使用して、3つの異なる閉ループプロトコルを適用します。 簡単に言えば、記載されたプロトコルは、アクティブおよびパッシブ膜特性の大きな集合の特性に関連する、電流クランプ刺激波形のシリーズの最初の自動注入されています。これらは、刺激波形の定型一連の応答特性の点で細胞の電気生理学的表現型を捕捉するために提案されています。セルの電子コードとして知られている（ 例えば 、参照してください＆＃160; 13,14）が 、電気的応答のようなコレクションは、客観的に、それらの電気的特性に基づいて神経細胞を分類するためにいくつかの研究室で使用されます。これは、比例積分微分（PID）コントローラにより発火の速度の閉ループリアルタイム制御を含む革新的な技術によって、固定入出力伝達関係（FI曲線）の分析が含まれ、第二のインビトロ製剤10と、コンピュータでシミュレートされた仮想のGABA作動性介在ニューロンの手段により2同時に記録錐体ニューロンのリアルタイムで第人工接続で現実的なインビボの様な背景シナプス活性のレクリエーション。 さらに、LCGは、単一の電極を用いたダイナミッククランププロトコルを実装することができ、活性電極報酬（AEC）15、として知られる技術を実装しています。これは望ましくない影響を補償することができます（Aそれは、細胞内刺激を送達するために使用される場合に生じる記録電極のrtifacts）。この方法は、記録回路の等価電気特性のノンパラメトリック推定に基づいています。 このホワイトペーパーに記載された技術と実験プロトコルは、容易に従来のオープンループ電圧と電流クランプ実験に適用することができ、 生体内 17,18 に 、このような細胞外4,16のような他の製剤、または細胞内記録に拡張することができます。全細胞パッチクランプ電気生理学のセットアップの注意深いアセンブリは安定した高品質の記録のために非常に重要なステップです。以下では、そのような実験は、実験者に既に利用可能であることを前提とし、LCGの使用法を説明する上で私たちの注意を集中します。読者は、最適化とデバッグに関する追加のヒントについては、19〜22に指摘されています。

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Tissue slicer</td>
			<td>Leica</td>
			<td>VT-1000S</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette puller</td>
			<td>Sutter</td>
			<td>P-97</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipettes</td>
			<td>WPI</td>
			<td>1B150F-4</td>
			<td>1.5/0.84 mm OD/ID, with filament</td>
		</tr>
		<tr>
			<td>Vibration isolation table</td>
			<td>TMC</td>
			<td>20 Series</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Leica</td>
			<td>DMLFS</td>
			<td>40X Immersion Objective</td>
		</tr>
		<tr>
			<td>Manipulators</td>
			<td>Scientifica</td>
			<td>PatchStar</td>
			<td></td>
		</tr>
		<tr>
			<td>Amplifiers</td>
			<td>Axon Instruments</td>
			<td>MultiClamp 700B</td>
			<td>Computer controlled</td>
		</tr>
		<tr>
			<td>Data acquisition card</td>
			<td>National Instruments</td>
			<td>PCI-6229</td>
			<td>Supported by Comedi Linux Drivers</td>
		</tr>
		<tr>
			<td>Desktop computer</td>
			<td>Dell</td>
			<td>Optiplex 7010 Tower</td>
			<td>OS: real-time Linux</td>
		</tr>
		<tr>
			<td>Oscilloscopes</td>
			<td>Tektronix</td>
			<td>TDS-1002</td>
			<td></td>
		</tr>
		<tr>
			<td>Perfusion Pump</td>
			<td>Gibson</td>
			<td>MINIPULS3</td>
			<td>Used with R4 Pump head (F117606)</td>
		</tr>
		<tr>
			<td>Temperature controller</td>
			<td>Multichannel Systems</td>
			<td>TC02</td>
			<td>PH01 Perfusion Cannula</td>
		</tr>
		<tr>
			<td>Manometer</td>
			<td>Testo</td>
			<td>510</td>
			<td>Optional</td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>Memmert</td>
			<td>WB14</td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Sigma</td>
			<td>71376</td>
			<td>ACSF</td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Sigma</td>
			<td>P9541</td>
			<td>ACSF, ICS</td>
		</tr>
		<tr>
			<td>NaH2PO4</td>
			<td>Sigma</td>
			<td>S3139</td>
			<td>ACSF</td>
		</tr>
		<tr>
			<td>NaHCO3</td>
			<td>Sigma</td>
			<td>S6014</td>
			<td>ACSF</td>
		</tr>
		<tr>
			<td>CaCl2</td>
			<td>Sigma</td>
			<td>C1016</td>
			<td>ACSF</td>
		</tr>
		<tr>
			<td>MgCl2</td>
			<td>Sigma</td>
			<td>M8266</td>
			<td>ACSF</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Sigma</td>
			<td>G7528</td>
			<td>ACSF</td>
		</tr>
		<tr>
			<td>K-Gluconate</td>
			<td>Sigma</td>
			<td>G4500</td>
			<td>ICS</td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Sigma</td>
			<td>H3375</td>
			<td>ICS</td>
		</tr>
		<tr>
			<td>Mg-ATP</td>
			<td>Sigma</td>
			<td>A9187</td>
			<td>ICS</td>
		</tr>
		<tr>
			<td>Na2-GTP</td>
			<td>Sigma</td>
			<td>51120</td>
			<td>ICS</td>
		</tr>
		<tr>
			<td>Na2-Phosphocreatine</td>
			<td>Sigma</td>
			<td>P7936</td>
			<td>ICS</td>
		</tr>
	</tbody>
</table>

real-time electrophysiology: using closed-loop protocols to probe neuronal dynamics and beyond

実験的神経科学は、新規の開発と応用への関心の高まりを目撃し、多くの場合、複雑な刺激が、システムの応答にリアルタイムに依存​​する適用、閉ループプロトコルれます。最近のアプリケーションは、光遺伝学3を使用して、皮質脳卒中後の発作の制御に、マウス1とゼブラフィッシュ2の両方の運動反応を研究するための仮想現実システムの実装の ​​範囲です。閉ループ技術の重要な利点は、直接アクセスすることはできませんまたは、同時に実験スループットを最大化しながら、このような神経細胞の興奮4や信頼性などの複数の変数に依存し、より高い次元の特性を探査する能力にあります。この貢献ではと細胞電気生理学との関連で、我々はREC、錐体皮質ニューロンの応答特性の研究に閉ループの様々なプロトコルを適用する方法について説明します若年ラットの体性感覚皮質から急性脳スライスにおけるパッチクランプ法で細胞内orded。何の市販またはオープンソースソフトウェアを効率的にここに記載の実験を行うために必要なすべての機能を提供しないように、LCG 5と呼ばれる新しいソフトウェアツールボックスは、そのモジュラー構造のコンピュータ·コードの再利用を最大化し、新たな実験パラダイムの実装を容易に、開発されました。刺激波形は、コンパクトなメタ記述を使用して指定されており、完全な実験プロトコルは、テキストベースの設定ファイルに記述されています。さらに、LCGは、試験の反復と実験プロトコルの自動化に適しているコマンドライン·インタフェースを備えています。

前のセクションでは、L5錐体細胞の電気生理学的特性を特徴づけるために、ソフトウェアツールボックスのLCGを使用して、スライス標本におけるインビボ様シナプス活性を再作成する方法を説明してきました。コマンド·ライン·インターフェースと半自動プロトコルの使用は、生成されたデータの出力および品質に大きな影響を持つことができ、実験の再現性及び効率性を好みます。?...

Watch this Scientific Journal Video about Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond at JoVE.com

Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond

Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board.

リアルタイム電気生理学：プローブ神経ダイナミクスとその先にクローズド·ループ·プロトコルの使用

Experimental neuroscience is witnessing an increased interest in the development and application of novel and often complex, closed-loop protocols, where ...

real-time-electrophysiology-using-closed-loop-protocols-to-probe

Research

JoVE Journal

Neuroscience

11.3K ビュー.  University of Antwerp. Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board. 

ビデオ: Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond

An Experimental Platform to Study the Closed-loop Performance of Brain-machine Interfaces

The non-stationary nature and variability of neuronal signals is a fundamental problem in brain-machine interfacing. We developed a brain-machine interface to assess the robustness of different control-laws applied to a closed-loop image stabilization task. Taking advantage of the well-characterized fly visuomotor pathway we record the electrical activity from an identified, motion-sensitive neuron, H1, to control the yaw rotation of a two-wheeled robot. The robot is equipped with 2 high-speed video cameras providing visual motion input to a fly placed in front of 2 CRT computer monitors. The activity of the H1 neuron indicates the direction and relative speed of the robot's rotation. The neural activity is filtered and fed back into the steering system of the robot by means of proportional and proportional/adaptive control. Our goal is to test and optimize the performance of various control laws under closed-loop conditions for a broader application also in other brain machine interfaces.

We use a closed-loop fly-machine interface to investigate general principles in neuronal control.

ブレインマシンインタフェースの閉ループ性能を研究する実験プラットフォーム

The non-stationary nature and variability of neuronal signals is a fundamental problem in brain-machine interfacing. We developed a brain-machine ...

神経科学

Multi-electrode Array Recordings of Neuronal Avalanches in Organotypic Cultures

The cortex is spontaneously active, even in the absence of any particular input or motor output. During development, this activity is important for the migration and differentiation of cortex cell types and the formation of neuronal connections1. In the mature animal, ongoing activity reflects the past and the present state of an animal into which sensory stimuli are seamlessly integrated to compute future actions. Thus, a clear understanding of the organization of ongoing i.e. spontaneous activity is a prerequisite to understand cortex function. 
Numerous recording techniques revealed that ongoing activity in cortex is comprised of many neurons whose individual activities transiently sum to larger events that can be detected in the local field potential (LFP) with extracellular microelectrodes, or in the electroencephalogram (EEG), the magnetoencephalogram (MEG), and the BOLD signal from functional magnetic resonance imaging (fMRI). The LFP is currently the method of choice when studying neuronal population activity with high temporal and spatial resolution at the mesoscopic scale (several thousands of neurons). At the extracellular microelectrode, locally synchronized activities of spatially neighbored neurons result in rapid deflections in the LFP up to several hundreds of microvolts. When using an array of microelectrodes, the organizations of such deflections can be conveniently monitored in space and time. 
Neuronal avalanches describe the scale-invariant spatiotemporal organization of ongoing neuronal activity in the brain2,3. They are specific to the superficial layers of cortex as established in vitro4,5, in vivo in the anesthetized rat 6, and in the awake monkey7. Importantly, both theoretical and empirical studies2,8-10 suggest that neuronal avalanches indicate an exquisitely balanced critical state dynamics of cortex that optimizes information transfer and information processing.
In order to study the mechanisms of neuronal avalanche development, maintenance, and regulation, in vitro preparations are highly beneficial, as they allow for stable recordings of avalanche activity under precisely controlled conditions. The current protocol describes how to study neuronal avalanches in vitro by taking advantage of superficial layer development in organotypic cortex cultures, i.e. slice cultures, grown on planar, integrated microelectrode arrays (MEA; see also 11-14).

A robust way to study neuronal avalanches, i.e. scale-invariant spatio-temporal activity bursts, indicative of critical state dynamics in cortex. Avalanches emerge spontaneously in developing superficial layers of cultured cortex which allows for long-term measurements of the activity with planar integrated multi-electrode arrays (MEA) under precisely controlled conditions.

器官培養における神経雪崩のマルチ電極アレイの録音

The cortex is spontaneously active, even in the absence of any particular input or motor output.  During development, this activity is important for the ...

Simultaneous Electroencephalography, Real-time Measurement of Lactate Concentration and Optogenetic Manipulation of Neuronal Activity in the Rodent Cerebral Cortex

Although the brain represents less than 5% of the body by mass, it utilizes approximately one quarter of the glucose used by the body at rest1. The function of non rapid eye movement sleep (NREMS), the largest portion of sleep by time, is uncertain. However, one salient feature of NREMS is a significant reduction in the rate of cerebral glucose utilization relative to wakefulness2-4. This and other findings have led to the widely held belief that sleep serves a function related to cerebral metabolism. Yet, the mechanisms underlying the reduction in cerebral glucose metabolism during NREMS remain to be elucidated.
	One phenomenon associated with NREMS that might impact cerebral metabolic rate is the occurrence of slow waves, oscillations at frequencies less than 4 Hz, in the electroencephalogram5,6. These slow waves detected at the level of the skull or cerebral cortical surface reflect the oscillations of underlying neurons between a depolarized/up state and a hyperpolarized/down state7. During the down state, cells do not undergo action potentials for intervals of up to several hundred milliseconds. Restoration of ionic concentration gradients subsequent to action potentials represents a significant metabolic load on the cell8; absence of action potentials during down states associated with NREMS may contribute to reduced metabolism relative to wake.
	Two technical challenges had to be addressed in order for this hypothetical relationship to be tested. First, it was necessary to measure cerebral glycolytic metabolism with a temporal resolution reflective of the dynamics of the cerebral EEG (that is, over seconds rather than minutes). To do so, we measured the concentration of lactate, the product of aerobic glycolysis, and therefore a readout of the rate of glucose metabolism in the brains of mice. Lactate was measured using a lactate oxidase based real time sensor embedded in the frontal cortex. The sensing mechanism consists of a platinum-iridium electrode surrounded by a layer of lactate oxidase molecules. Metabolism of lactate by lactate oxidase produces hydrogen peroxide, which produces a current in the platinum-iridium electrode. So a ramping up of cerebral glycolysis provides an increase in the concentration of substrate for lactate oxidase, which then is reflected in increased current at the sensing electrode. It was additionally necessary to measure these variables while manipulating the excitability of the cerebral cortex, in order to isolate this variable from other facets of NREMS.
	We devised an experimental system for simultaneous measurement of neuronal activity via the elecetroencephalogram, measurement of glycolytic flux via a lactate biosensor, and manipulation of cerebral cortical neuronal activity via optogenetic activation of pyramidal neurons. We have utilized this system to document the relationship between sleep-related electroencephalographic waveforms and the moment-to-moment dynamics of lactate concentration in the cerebral cortex. The protocol may be useful for any individual interested in studying, in freely behaving rodents, the relationship between neuronal activity measured at the electroencephalographic level and cellular energetics within the brain.

A procedure is described for manipulating the activity of cerebral cortical pyramidal neurons optogenetically while the electroencephalogram, electromyogram, and cerebral lactate concentration are monitored. Experimental recordings are performed on cable-tethered mice while they undergo spontaneous sleep/wake cycles. Optogenetic equipment is assembled in our laboratory; recording equipment is commercially available.

同時脳波、リアルタイム乳酸濃度の測定と齧歯類大脳皮質ニューロン活動のOptogeneticマニピュレーション

Although the brain represents less than 5% of the body  by mass, it utilizes approximately one quarter of the glucose used by the body  at rest1. The ...

Real-Time Impedance-based Cell Analyzer as a Tool to Delineate Molecular Pathways Involved in Neurotoxicity and Neuroprotection in a Neuronal Cell Line

Many brain-related disorders have neuronal cell death involved in their pathophysiology. Improved in vitro models to study neuroprotective or neurotoxic effects of drugs and downstream pathways involved would help gain insight into the molecular mechanisms of neuroprotection/neurotoxicity and could potentially facilitate drug development. However, many existing in vitro toxicity assays have major limitations &#8211; most assess neurotoxicity and neuroprotection at a single time point, not allowing to observe the time-course and kinetics of the effect. Furthermore, the opportunity to collect information about downstream signaling pathways involved in neuroprotection in real-time would be of great importance. In the current protocol we describe the use of a real-time impedance-based cell analyzer to determine neuroprotective effects of serotonin 2A (5-HT2A) receptor agonists in a neuronal cell line under label-free and real-time conditions using impedance measurements. Furthermore, we demonstrate that inhibitors of second messenger pathways can be used to delineate downstream molecules involved in the neuroprotective effect. We also describe the utility of this technique to determine whether an effect on cell proliferation contributes to an observed neuroprotective effect. The system utilizes special microelectronic plates referred to as E-Plates which contain alternating gold microelectrode arrays on the bottom surface of the wells, serving as cell sensors. The impedance readout is modified by the number of adherent cells, cell viability, morphology, and adhesion. A dimensionless parameter called Cell Index is derived from the electrical impedance measurements and is used to represent the cell status. Overall, the real-time impedance-based cell analyzer allows for real-time, label-free assessment of neuroprotection and neurotoxicity, and the evaluation of second messenger pathways involvement, contributing to more detailed and high-throughput assessment of potential neuroprotective compounds in vitro, for selecting therapeutic candidates.

Improved in vitro neurotoxicity assays would aid the identification of new neuroprotective compounds. The utility of a real-time impedance-based cell analyzer to determine cytotoxicity and cytoprotection in neuronal cell lines and to delineate the involvement of second messenger pathways, thus gaining insight in the mechanism of neuroprotection is presented.

リアルタイム神経細胞株に神経毒性および神経保護に関与する分子経路を描写するツールとしてのインピーダンスベースの細胞分析装置

Many brain-related disorders have neuronal cell death involved in their pathophysiology. Improved in vitro models to study neuroprotective or neurotoxic ...

Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks

Information coding in the Central Nervous System (CNS) remains unexplored. There is mounting evidence that, even at a very low level, the representation of a given stimulus might be dependent on context and history. If this is actually the case, bi-directional interactions between the brain (or if need be a reduced model of it) and sensory-motor system can shed a light on how encoding and decoding of information is performed. Here an experimental system is introduced and described in which the activity of a neuronal element (i.e., a network of neurons extracted from embryonic mammalian hippocampi) is given context and used to control the movement of an artificial agent, while environmental information is fed back to the culture as a sequence of electrical stimuli. This architecture allows a quick selection of diverse encoding, decoding, and learning algorithms to test different hypotheses on the computational properties of neuronal networks.

In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body.

閉ループ神経のロボット実験は、神経回路網の計算特性を試験すること

Information coding in the Central Nervous System (CNS) remains unexplored. There is mounting evidence that, even at a very low level, the representation ...

Prolonged Incubation of Acute Neuronal Tissue for Electrophysiology and Calcium-imaging

Acute neuronal tissue preparations, brain slices and retinal wholemount, can usually only be maintained for 6 - 8 h following dissection. This limits the experimental time, and increases the number of animals that are utilized per study. This limitation specifically impacts protocols such as calcium imaging that require prolonged pre-incubation with bath-applied dyes. Exponential bacterial growth within 3 - 4 h after slicing is tightly correlated with a decrease in tissue health. This study describes a method for&#160;limiting the proliferation of bacteria in acute preparations to maintain viable neuronal tissue for prolonged periods of time (&#62;24 h) without the need for antibiotics, sterile procedures, or tissue culture media containing growth factors. By cycling the extracellular fluid through UV irradiation and keeping the tissue in a custom holding chamber at 15 - 16 &#176;C, the tissue shows no difference in electrophysiological properties, or calcium signaling through intracellular calcium dyes at &#62;24 h postdissection. These methods will not only extend experimental time for those using acute neuronal tissue, but will reduce the number of animals required to complete experimental goals, and will set a gold standard for acute neuronal tissue incubation.

Once removed from the body, neuronal tissue is greatly affected by environmental conditions, leading to eventual degradation of the tissue after 6 - 8 h. Using a unique incubation method, which closely monitors and regulates the extracellular environment of the tissue, tissue viability can be significantly extended for &#62;24 h.

電気生理学およびカルシウムイメージングのための急性神経組織の長期のインキュベーション

Acute neuronal tissue preparations, brain slices and retinal wholemount, can usually only be maintained for 6 - 8 h following dissection. This limits the ...

Using Neuron Spiking Activity to Trigger Closed-Loop Stimuli in Neurophysiological Experiments

Closed-loop neurophysiological systems use patterns of neuronal activity to trigger stimuli, which in turn affect brain activity. Such closed-loop systems are already found in clinical applications, and are important tools for basic brain research. A particularly interesting recent development is the integration of closed-loop approaches with optogenetics, such that specific patterns of neuronal activity can trigger optical stimulation of selected neuronal groups. However, setting up an electrophysiological system for closed-loop experiments can be difficult. Here, a ready-to-apply Matlab code is provided for triggering stimuli based on the activity of single or multiple neurons. This sample code can be easily modified based on individual needs. For instance, it shows how to trigger sound stimuli and how to change it to trigger an external device connected to a PC serial port. The presented protocol is designed to work with a popular neuronal recording system for animal studies (Neuralynx). The implementation of closed-loop stimulation is demonstrated in an awake rat.

This protocol demonstrates how to use an electrophysiological system for closed-loop stimulation triggered by neuronal activity patterns. Sample Matlab code that can be easily modified for different stimulation devices is also provided.

ニューロンスパイク活性を利用して神経生理学実験における閉ループ刺激を引き起こす

Closed-loop neurophysiological systems use patterns of neuronal activity to trigger stimuli, which in turn affect brain activity. Such closed-loop systems ...

Open-Source Real-Time Closed-Loop Electrical Threshold Tracking for Translational Pain Research

Nociceptors are a class of primary afferent neurons that signal potentially harmful noxious stimuli. An increase in nociceptor excitability occurs in acute and chronic pain conditions. This produces abnormal ongoing activity or reduced activation thresholds to noxious stimuli. Identifying the cause of this increased excitability is required for the development and validation of mechanism-based treatments. Single-neuron electrical threshold tracking can quantify nociceptor excitability. Therefore, we have developed an application to allow such measurements and demonstrate its use in humans and rodents. APTrack provides real-time data visualization and action potential identification using a temporal raster plot. Algorithms detect action potentials by threshold crossing and monitor their latency after electrical stimulation. The plugin then modulates the electrical stimulation amplitude using an up-down method to estimate the electrical threshold of the nociceptors. The software was built upon the Open Ephys system (V0.54) and coded in C++ using the JUCE framework. It runs on Windows, Linux, and Mac operating systems. The open-source code is available (<a data-saferedirecturl="https://www.google.com/url?q=https://github.com/Microneurography/APTrack&amp;source=gmail&amp;ust=1680789829274000&amp;usg=AOvVaw0nMk9J_EI2jUn8SlmC5JJm" href="https://github.com/Microneurography/APTrack" target="_blank">https://github.com/Microneurography/APTrack</a>). The electrophysiological recordings were taken from nociceptors in both a mouse skin-nerve preparation using the teased fiber method in the saphenous nerve and in healthy human volunteers using microneurography in the superficial peroneal nerve. Nociceptors were classified by their response to thermal and mechanical stimuli, as well as by monitoring the activity-dependent slowing of the conduction velocity. The software facilitated the experiment by simplifying the action potential identification through the temporal raster plot. We demonstrate real-time closed-loop electrical threshold tracking of single-neuron action potentials during&#160;in vivo&#160;human microneurography, for the first time, and during&#160;ex vivo&#160;mouse electrophysiological recordings of C-fibers and A&#948;-fibers. We establish proof of principle by showing that the electrical threshold of a human heat-sensitive C-fiber nociceptor is reduced by heating the receptive field. This plugin enables the electrical threshold tracking of single-neuron action potentials and allows the quantification of changes in nociceptor excitability.

APTrack is a software plugin developed for the Open Ephys platform that enables real-time data visualization and the closed-loop electrical threshold tracking of neuronal action potentials. We have successfully used this in microneurography for human C-fiber nociceptors and mouse C-fiber and A&#948;-fiber nociceptors.

トランスレーショナルペイン研究のためのオープンソースのリアルタイム閉ループ電気閾値追跡

Nociceptors are a class of primary afferent neurons that signal potentially harmful noxious stimuli. An increase in nociceptor excitability occurs in ...

大うつ病の治療のための脳深部刺激療法

Closed-Loop Neurostimulation for Biomarker-Driven, Personalized Treatment of Major Depressive Disorder

Deep brain stimulation involves the administration of electrical stimulation to targeted brain regions for therapeutic benefit. In the context of major depressive disorder (MDD), most studies to date have administered continuous or open-loop stimulation with promising but mixed results. One factor contributing to these mixed results may stem from when the stimulation is applied. Stimulation administration specific to high-symptom states in a personalized and responsive manner may be more effective at reducing symptoms compared to continuous stimulation and may avoid diminished therapeutic effects related to habituation. Additionally, a lower total duration of stimulation per day is advantageous for reducing device energy consumption. This protocol describes an experimental workflow using a chronically implanted neurostimulation device to achieve closed-loop stimulation for individuals with treatment-refractory MDD. This paradigm hinges on determining a patient-specific neural biomarker that is related to states of high symptoms and programming the device detectors, such that stimulation is triggered by this read-out of symptom state. The described procedures include how to obtain neural recordings concurrent with patient symptom reports, how to use these data in a state-space model approach to differentiate low- and high-symptom states and corresponding neural features, and how to subsequently program and tune the device to deliver closed-loop stimulation therapy.

著者スポットライト:うつ病治療における閉ループ脳深部刺激療法の治療的利点 

Deep brain stimulation triggered by a patient-specific neural biomarker of a high-symptom state may better control symptoms of major depressive disorder compared to continuous, open-loop stimulation. This protocol provides a workflow for identifying a patient-specific neural biomarker and controlling the delivery of therapeutic stimulation based on the identified biomarker.

大うつ病性障害のバイオマーカー駆動型個別化治療のための閉ループ神経刺激

Deep brain stimulation involves the administration of electrical stimulation to targeted brain regions for therapeutic benefit. In the context of major ...