אנו מכירים תמיכה על ידי בית הספר למדעי מחשוב הפקולטה למדעי החקלאות, והנדסה של אוניברסיטת ניוקסל, על ידי אוניברסיטת Ulm, ועל ידי SciMedia בע&quot;מ (טוקיו, יפן).

<ol>
	<li>Gutierrez, G. J., Grashow, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+borealis+stomatogastric+nervous+system+dissection.">Cancer borealis stomatogastric nervous system dissection.</a> J Vis Exp. , (2009).</li><li>Bartos, M., Nusbaum, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intercircuit+control+of+motor+pattern+modulation+by+presynaptic+inhibition.">Intercircuit control of motor pattern modulation by presynaptic inhibition.</a> J. Neurosci. 17, 2247-2256 (1997).</li><li>Blitz, D. M., Nusbaum, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motor+pattern+selection+via+inhibition+of+parallel+pathways.">Motor pattern selection via inhibition of parallel pathways.</a> J Neurosci. 17, 4965-4975 (1997).</li><li>Stein, W., Smarandache, C. R., Nickmann, M., Hedrich, U. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+consequences+of+activity-dependent+synaptic+enhancement+at+a+crustacean+neuromuscular+junction.">Functional consequences of activity-dependent synaptic enhancement at a crustacean neuromuscular junction.</a> J Exp Biol. 209, 1285-12300 (2006).</li><li>Loew, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potentiometric+dyes:+Imaging+electrical+activity+of+cell+membranes.">Potentiometric dyes: Imaging electrical activity of cell membranes.</a> Pure &#38; Appl Chem. 68, 1405-1409 (1996).</li><li>Tominaga, T., Tominaga, Y., Yamada, H., Matsumoto, G., Ichikawa, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantification+of+optical+signals+with+electrophysiological+signals+in+neural+activities+of+Di-4-ANEPPS+stained+rat+hippocampal+slices.">Quantification of optical signals with electrophysiological signals in neural activities of Di-4-ANEPPS stained rat hippocampal slices.</a> J Neurosci Meth. 102, 11-23 (2000).</li><li>Heinzel, H. G., Weimann, J. M., Marder, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+behavioral+repertoire+of+the+gastric+mill+in+the+crab,+Cancer+pagurus:+an+in+situ+endoscopic+and+electrophysiological+examination.">The behavioral repertoire of the gastric mill in the crab, Cancer pagurus: an in situ endoscopic and electrophysiological examination.</a> J Neurosci. 13, 1793-1803 (1993).</li><li>Zecevic, D., Wu, J. -. Y., Cohen, L. B., London, J. A., H&#246;pp, H. P., Falk, C. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hundreds+of+neurons+in+the+Aplysia+abdominal+ganglion+are+active+during+the+gill-withdrawal+reflex.">Hundreds of neurons in the Aplysia abdominal ganglion are active during the gill-withdrawal reflex.</a> J Neurosci. 9, 3681-3689 (1989).</li><li>Briggman, K. L., Kristan, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+dedicated+and+multifunctional+neural+circuits+generating+distinct+behaviors.">Imaging dedicated and multifunctional neural circuits generating distinct behaviors.</a> J Neurosci. 26, 10925-10933 (2006).</li><li>Nusbaum, M. P., Beenhakker, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+small-systems+approach+to+motor+pattern+generation.">A small-systems approach to motor pattern generation.</a> Nature. 417, 343-350 (2002).</li><li>Marder, E., Bucher, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+circuit+dynamics+using+the+stomatogastric+nervous+system+of+lobsters+and+crabs.">Understanding circuit dynamics using the stomatogastric nervous system of lobsters and crabs.</a> Ann Rev Physiol. 69, 291-316 (2007).</li><li>Grillner, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+pattern+generation:+the+cellular+and+computational+logic+of+networks+in+motion.">Biological pattern generation: the cellular and computational logic of networks in motion.</a> Neuron. 52, 751-766 (2006).</li><li>Yuste, R., MacLean, J. N., Smith, J., Lansner, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cortex+as+a+central+pattern+generator.">The cortex as a central pattern generator.</a> Nat Rev Neurosci. 6, 477-483 (2005).</li><li>Stein, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+stomatogastric+rhythms.">Modulation of stomatogastric rhythms.</a> J Comp Physiol A. 195, 989-1009 (2009).</li></ol>

אין ניגודי אינטרסים הכריז.

צבען רגיש מתח הדמיה 8,9 של STG נוירונים בשילוב עם שיטות מסורתיות electrophysiology (הקלטות אלקטרודה תוך תאית ו) מאפשר הבנה משופרת של כמה קטן זה, עובד ידוע ומורכב עדיין המערכת העצבית. STG היא אב טיפוס של גנרטור דפוס מרכזי (CPG) רשתות נוירונים (זה כולל קצב השוער ובקיבה טחנת רשתות) 10, 11, וכך להבין טוב יותר את המאפיינים תפקודית מתהווה של STG גם יעזור להבין איך בכלל רשתות CPG ליצור רמה הרשת שלהם פונקציונליות. רשתות CPG לשחק תפקיד קריטי שליטה מוטורית 12 וגם יותר פונקציות קוגניטיביות 13, וכתוצאה מכך הבנה טובה יותר של תכונות מתהוות שלהם עשויה להיות השפעה גדולה בתחומים רבים של מדעי המוח.

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>MiCAM02</td>
<td>&nbsp;</td>
<td>SciMedia Ltd, Tokyo, Japan</td>
<td>&nbsp;</td>
<td>Imaging system</td>
</tr>
<tr>
<td>BVAna v.10.08</td>
<td>&nbsp;</td>
<td>SciMedia, Tokyo, Japab</td>
<td>&nbsp;</td>
<td>Data analysis software for the MiCAM 02 imaging system</td>
</tr>
<tr>
<td>HL-151</td>
<td>&nbsp;</td>
<td>Moritex, Tokyo, Japan</td>
<td>&nbsp;</td>
<td>Ultra-low ripple halogen light source</td>
</tr>
<tr>
<td>BX51 WI</td>
<td>&nbsp;</td>
<td>Olympus, Tokyo, Japan</td>
<td>&nbsp;</td>
<td>Upright microscope for epifluorescence imaging</td>
</tr>
<tr>
<td>20x imaging objective </td>
<td>&nbsp;</td>
<td>Olympus Corporation, Tokyo, Japan</td>
<td>XLUMPLFL20XW/0.95</td>
<td>NA 0.95, WD 2.0mm</td>
</tr>
<tr>
<td>10x imaging objective </td>
<td>&nbsp;</td>
<td>Olympus Corporation, Tokyo, Japan</td>
<td>UMPLFL10XW</td>
<td>NA 0.30, WD 3.3mm</td>
</tr>
<tr>
<td>Filter cube with 480-550 nm excitation filter and 590nm emission filter </td>
<td>&nbsp;</td>
<td>Olympus Corporation, Tokyo, Japan</td>
<td>MSWG2</td>
<td>&nbsp;</td>
<tr>
<td>Antivibration table</td>
<td>&nbsp;</td>
<td>Scientifica Ltd, Uckfield, UK</td>
<td>63-534</td>
<td>&nbsp;</td>
<tr>
<td>PatchStar electrode manipulator</td>
<td>&nbsp;</td>
<td>Scientifica Ltd, Uckfield, UK</td>
<td>PS-7000C</td>
<td>Micro-electrode manipulator</td>
</tr>
<tr>
<td>CED Power 1401</td>
<td>&nbsp;</td>
<td>Cambridge Electronic Design, Cambridge, UK</td>
<td>&nbsp;</td>
<td>Data acquisition board</td>
</tr>
<tr>
<td>DL708E Oscilloscope</td>
<td>&nbsp;</td>
<td>Yokogawa, Tokyo, Japan</td>
<td>&nbsp;</td>
<td>Intracellular amplifier</td>
</tr>
<tr>
<td>AC differential amplifier</td>
<td>&nbsp;</td>
<td>University of Kaiserslautern, Germany</td>
<td>&nbsp;</td>
<td>Extracellular amplifier</td>
</tr>
<tr>
<td>P-97 Flaming &#x2013; Brown type electrode puller</td>
<td>&nbsp;</td>
<td>Sutter Instruments, Novato, CA, USA</td>
<td>&nbsp;</td>
<td>Electrode puller</td>
</tr>
<tr>
<td>Sigma Microcentrifuge 1-14</td>
<td>&nbsp;</td>
<td>Sigma, Osterode, Germany</td>
<td>&nbsp;</td>
<td>Centrifuge</td>
</tr>
<tr>
<td>Genex Pipettors Mline</td>
<td>&nbsp;</td>
<td>Scientific Laboratory Supplies, UK</td>
<td>PIP7774</td>
<td>PIP7774</td>
</tr>
<tr>
<td>Glass micropipette with filament</td>
<td>&nbsp;</td>
<td>Science Products, Hofheim, Germany</td>
<td>GB100TF 8P</td>
<td>Glass for microelectrodes</td>
</tr>
<tr>
<td>MicroFil &#x2013; 34G</td>
<td>&nbsp;</td>
<td>World Precision Instruments, Sarasota, FL, USA</td>
<td>&nbsp;</td>
<td>Microfil needle</td>
</tr>
<tr>
<td>Spike 2 v6.10</td>
<td>&nbsp;</td>
<td>Cambridge Electronic Design, Cambridge, UK</td>
<td>&nbsp;</td>
<td>Electrophysiology software</td>
</tr>
<tr>
<td>Di-8-ANEPPQ</td>
<td>&nbsp;</td>
<td>Cambridge Bioscience Ltd, Cambridge, UK</td>
<td>BT61014</td>
<td>Fluorescent voltage sensitive dye</td>
</tr>
<tr>
<td>F-127 Pluronic Acid, DMSO</td>
<td>&nbsp;</td>
<td>Invitrogen, Paisley, UK</td>
<td>P-3000MP</td>
<td>Solvent</td>
</tr>
<tr>
<td>NaCl</td>
<td>&nbsp;</td>
<td>Sigma &#x2013; Aldrich, Poole, UK</td>
<td>S9888</td>
<td>Crab saline component</td>
</tr>
<tr>
<td>CaCl2 . 2H2O</td>
<td>&nbsp;</td>
<td>Sigma &#x2013; Aldrich, Poole, UK</td>
<td>C3881</td>
<td>Crab saline component</td>
</tr>
<tr>
<td>KCl</td>
<td>&nbsp;</td>
<td>Sigma &#x2013; Aldrich, Poole, UK</td>
<td>P3911</td>
<td>Crab saline component, electrolyte solution</td>
</tr>
<tr>
<td>MgCl2 . 6H2O</td>
<td>&nbsp;</td>
<td>Sigma &#x2013; Aldrich, Poole, UK</td>
<td>M9272</td>
<td>Crab saline component</td>
</tr>
<tr>
<td>Trizma base</td>
<td>&nbsp;</td>
<td>Sigma &#x2013; Aldrich, Poole, UK</td>
<td>T1503</td>
<td>Crab saline component</td>
</tr>
<tr>
<td>Maleic acid</td>
<td>&nbsp;</td>
<td>Sigma &#x2013; Aldrich, Poole, UK</td>
<td>M0375</td>
<td>Crab saline component</td>
</tr>
<tr>
<td>Elastosil RT-601</td>
<td>&nbsp;</td>
<td>Wacker, Munich, Germany</td>
<td>&nbsp;</td>
<td>Lining of Petri dishes</td>
</tr>		</tbody>
		</table>
		</div>

optical imaging of neurons in the crab stomatogastric ganglion with voltage-sensitive dyes

מתח רגיש הדמיה צבען של נוירונים היא מתודולוגיה מפתח להבנת אופן רשתות נוירונים מאורגנים וכיצד פעילות סימולטנית של הנוירונים המשתתפים מוביל הופעתה של פונקציונליות אינטגרלי של הרשת. כאן אנו מציגים את המתודולוגיה של היישום של טכניקה זו כדי לייצר נוירונים דפוס מזוהה ב הגנגליון סרטן stomatogastric. אנו מדגימים את הטעינה של הנוירונים האלה עם הניאון מתח רגיש לצבוע Di-8-ANEPPQ ואנחנו מראים כיצד התמונה את הפעילות של הנוירונים טעון לצבוע באמצעות MiCAM02 מהירות גבוהה ברזולוציה גבוהה מצלמה CCD מערכת הדמיה. אנו מדגימים את ניתוח הנתונים הדמיה רשמה באמצעות תוכנת הדמיה BVAna הקשורים MiCAM02 מערכת ההדמיה. הדמיה סימולטני מתח רגיש לצבוע פעילות מפורט של נוירונים מרובים הגנגליון סרטן stomatogastric מיושם יחד עם טכניקות מסורתיות electrophysiology (הקלטות תאיים תאית) נפתח באופן קיצוני הזדמנויות חדשות להבנה של איך לעבוד מרכזי גנרטור דפוס רשתות עצביות.

Watch this Scientific Journal Video about Optical Imaging of Neurons in the Crab Stomatogastric Ganglion with Voltage-sensitive Dyes at JoVE.com

Optical Imaging of Neurons in the Crab Stomatogastric Ganglion with Voltage-sensitive Dyes

כאן אנו מציגים את המתודולוגיה של מהיר הדמיה ברזולוציה גבוהה פלואורסצנטי מתח רגיש צבען של פעילות מפורט של נוירונים הגנגליון stomatogastric סרטן.

דימות אופטי של נוירונים גנגליון סרטן Stomatogastric עם מתח רגיש צבעים

Voltage-sensitive dye imaging of neurons is a key methodology for the understanding of how neuronal networks are organised and how the simultaneous ...

optical-imaging-neurons-crab-stomatogastric-ganglion-with-voltage

Nanyang Technological University

Research

JoVE Journal

Neuroscience

12.9K Views.  Ulm University. כאן אנו מציגים את המתודולוגיה של מהיר הדמיה ברזולוציה גבוהה פלואורסצנטי מתח רגיש צבען של פעילות מפורט של נוירונים הגנגליון stomatogastric סרטן.

Video: Optical Imaging of Neurons in the Crab Stomatogastric Ganglion with Voltage-sensitive Dyes

Neuromodulation and Mitochondrial Transport: Live Imaging in Hippocampal Neurons over Long Durations

To understand the relationship between mitochondrial transport and neuronal function, it is critical to observe mitochondrial behavior in live cultured neurons for extended durations1-3. This is now possible through the use of vital dyes and fluorescent proteins with which cytoskeletal components, organelles, and other structures in living cells can be labeled and then visualized via dynamic fluorescence microscopy. For example, in embryonic chicken sympathetic neurons, mitochondrial movement was characterized using the vital dye rhodamine 1234. In another study, mitochondria were visualized in rat forebrain neurons by transfection of mitochondrially targeted eYFP5. However, imaging of primary neurons over minutes, hours, or even days presents a number of issues. Foremost among these are: 1) maintenance of culture conditions such as temperature, humidity, and pH during long imaging sessions; 2) a strong, stable fluorescent signal to assure both the quality of acquired images and accurate measurement of signal intensity during image analysis; and 3) limiting exposure times during image acquisition to minimize photobleaching and avoid phototoxicity.
Here, we describe a protocol that permits the observation, visualization, and analysis of mitochondrial movement in cultured hippocampal neurons with high temporal resolution and under optimal life support conditions. We have constructed an affordable stage-top incubator that provides good temperature regulation and atmospheric gas flow, and also limits the degree of media evaporation, assuring stable pH and osmolarity. This incubator is connected, via inlet and outlet hoses, to a standard tissue culture incubator, which provides constant humidity levels and an atmosphere of 5-10% CO2/air. This design offers a cost-effective alternative to significantly more expensive microscope incubators that don't necessarily assure the viability of cells over many hours or even days. To visualize mitochondria, we infect cells with a lentivirus encoding a red fluorescent protein that is targeted to the mitochondrion. This assures a strong and persistent signal, which, in conjunction with the use of a stable xenon light source, allows us to limit exposure times during image acquisition and all but precludes photobleaching and phototoxicity. Two injection ports on the top of the stage-top incubator allow the acute administration of neurotransmitters and other reagents intended to modulate mitochondrial movement. In sum, lentivirus-mediated expression of an organelle-targeted red fluorescent protein and the combination of our stage-top incubator, a conventional inverted fluorescence microscope, CCD camera, and xenon light source allow us to acquire time-lapse images of mitochondrial transport in living neurons over longer durations than those possible in studies deploying conventional vital dyes and off-the-shelf life support systems.

We describe a protocol that allows imaging of mitochondria in living neurons via fluorescence microscopy over long durations. Imaging over extended periods is accomplished through lentivirus-mediated expression of a mitochondrially targeted fluorescent protein and use of an inexpensive stage-top incubator that was designed and built in our laboratory.

Neuromodulation ותחבורה מיטוכונדריאלי: הדמיה חיה נוירונים בהיפוקמפוס פני משכי זמן ארוכים

To understand the relationship between mitochondrial transport and neuronal function, it is critical to observe mitochondrial behavior in live cultured ...

Genetic Study of Axon Regeneration with Cultured Adult Dorsal Root Ganglion Neurons

It is well known that mature neurons in the central nervous system (CNS) cannot regenerate their axons after injuries due to diminished intrinsic ability to support axon growth and a hostile environment in the mature CNS1,2. In contrast, mature neurons in the peripheral nervous system (PNS) regenerate readily after injuries3. Adult dorsal root ganglion (DRG) neurons are well known to regenerate robustly after peripheral nerve injuries. Each DRG neuron grows one axon from the cell soma, which branches into two axonal branches: a peripheral branch innervating peripheral targets and a central branch extending into the spinal cord. Injury of the DRG peripheral axons results in substantial axon regeneration, whereas central axons in the spinal cord regenerate poorly after the injury. However, if the peripheral axonal injury occurs prior to the spinal cord injury (a process called the conditioning lesion), regeneration of central axons is greatly improved4. Moreover, the central axons of DRG neurons share the same hostile environment as descending corticospinal axons in the spinal cord. Together, it is hypothesized that the molecular mechanisms controlling axon regeneration of adult DRG neurons can be harnessed to enhance CNS axon regeneration. As a result, adult DRG neurons are now widely used as a model system to study regenerative axon growth5-7.
Here we describe a method of adult DRG neuron culture that can be used for genetic study of axon regeneration in vitro. In this model adult DRG neurons are genetically manipulated via electroporation-mediated gene transfection6,8. By transfecting neurons with DNA plasmid or si/shRNA, this approach enables both gain- and loss-of-function experiments to investigate the role of any gene-of-interest in axon growth from adult DRG neurons. When neurons are transfected with si/shRNA, the targeted endogenous protein is usually depleted after 3-4 days in culture, during which time robust axon growth has already occurred, making the loss-of-function studies less effective. To solve this problem, the method described here includes a re-suspension and re-plating step after transfection, which allows axons to re-grow from neurons in the absence of the targeted protein. Finally, we provide an example of using this in vitro model to study the role of an axon regeneration-associated gene, c-Jun, in mediating axon growth from adult DRG neurons9.

An in vitro model for genetic study of axon regeneration using cultured adult mouse dorsal root ganglion neurons is described. The method includes a re-suspension/re-plating step to allow axon re-growth from neurons undergoing genetic manipulation. This approach is especially useful for loss-of-function studies of axon regeneration using RNAi-based protein knockdown.

המחקר הגנטי של הדור הבא אקסון עם נוירונים בתרבית למבוגרים הגנגליון הגב שורש

It is well known that mature neurons in the central nervous system (CNS) cannot regenerate their axons after injuries due to diminished intrinsic ability ...

Voltage-sensitive Dye Recording from Axons, Dendrites and Dendritic Spines of Individual Neurons in Brain Slices

Understanding the biophysical properties and functional organization of single neurons and how they process information is fundamental for understanding how the brain works. The primary function of any nerve cell is to process electrical signals, usually from multiple sources. Electrical properties of neuronal processes are extraordinarily complex, dynamic, and, in the general case, impossible to predict in the absence of detailed measurements. To obtain such a measurement one would, ideally, like to be able to monitor, at multiple sites, subthreshold events as they travel from the sites of origin on neuronal processes and summate at particular locations to influence action potential initiation. This goal has not been achieved in any neuron due to technical limitations of measurements that employ electrodes. To overcome this drawback, it is highly desirable to complement the patch-electrode approach with imaging techniques that permit extensive parallel recordings from all parts of a neuron. Here, we describe such a technique - optical recording of membrane potential transients with organic voltage-sensitive dyes (Vm-imaging) - characterized by sub-millisecond and sub-micrometer resolution. Our method is based on pioneering work on voltage-sensitive molecular probes 2. Many aspects of the initial technology have been continuously improved over several decades 3, 5, 11. Additionally, previous work documented two essential characteristics of Vm-imaging. Firstly, fluorescence signals are linearly proportional to membrane potential over the entire physiological range (-100 mV to +100 mV; 10, 14, 16). Secondly, loading neurons with the voltage-sensitive dye used here (JPW 3028) does not have detectable pharmacological effects. The recorded broadening of the spike during dye loading is completely reversible 4, 7. Additionally, experimental evidence shows that it is possible to obtain a significant number (up to hundreds) of recordings prior to any detectable phototoxic effects 4, 6, 12, 13. At present, we take advantage of the superb brightness and stability of a laser light source at near-optimal wavelength to maximize the sensitivity of the Vm-imaging technique. The current sensitivity permits multiple site optical recordings of Vm transients from all parts of a neuron, including axons and axon collaterals, terminal dendritic branches, and individual dendritic spines. The acquired information on signal interactions can be analyzed quantitatively as well as directly visualized in the form of a movie.

An imaging technique for monitoring of membrane potential changes with sub-micrometer spatial and sub-millisecond temporal resolution is described. The technique, based on laser excitation of voltage-sensitive dyes, allows measurements of signals in axons and axon collaterals, terminal dendritic branches, and individual dendritic spines.

הקלטת דיי מתח רגישה מהאקסונים, הדנדריטים וקוצים הדנדריטים של נוירונים בודדים בפרוסות מוח

Understanding the biophysical properties and functional organization of single neurons and how they process information is fundamental for understanding ...

Implementing Dynamic Clamp with Synaptic and Artificial Conductances in Mouse Retinal Ganglion Cells

Ganglion cells are the output neurons of the retina and their activity reflects the integration of multiple synaptic inputs arising from specific neural circuits. Patch clamp techniques, in voltage clamp and current clamp configurations, are commonly used to study the physiological properties of neurons and to characterize their synaptic inputs. Although the application of these techniques is highly informative, they pose various limitations. For example, it is difficult to quantify how the precise interactions of excitatory and inhibitory inputs determine response output. To address this issue, we used a modified current clamp technique, dynamic clamp, also called conductance clamp 1, 2, 3 and examined the impact of excitatory and inhibitory synaptic inputs on neuronal excitability. This technique requires the injection of current into the cell and is dependent on the real-time feedback of its membrane potential at that time. The injected current is calculated from predetermined excitatory and inhibitory synaptic conductances, their reversal potentials and the cell's instantaneous membrane potential. Details on the experimental procedures, patch clamping cells to achieve a whole-cell configuration and employment of the dynamic clamp technique are illustrated in this video article. Here, we show the responses of mouse retinal ganglion cells to various conductance waveforms obtained from physiological experiments in control conditions or in the presence of drugs. Furthermore, we show the use of artificial excitatory and inhibitory conductances generated using alpha functions to investigate the responses of the cells.

This video article illustrates the set-up, the procedures to patch cell bodies and how to implement dynamic clamp recordings from ganglion cells in whole-mount mouse retinae. This technique allows the investigation of the precise contribution of excitatory and inhibitory synaptic inputs, and their relative magnitude and timing to neuronal spiking.

יישום קלאמפ דינמי עם Conductances Synaptic ומלאכותי בתאי עכבר גנגליון רשתית

Ganglion cells are the output neurons of the  retina and their activity reflects the integration of multiple synaptic inputs  arising from specific neural ...

Retrograde Labeling of Retinal Ganglion Cells in Adult Zebrafish with Fluorescent Dyes

As retrograde labeling retinal ganglion cells (RGCs) can isolate RGCs somata from dying sites, it has become the gold standard for counting RGCs in RGCs survival and regeneration experiments. Many studies have been performed in mammalian animals to research RGCs survival after optic nerve injury. However, retrograde labeling of RGCs in adult zebrafish has not yet been reported, though some alternative methods can count cell numbers in retinal ganglion cell layers (RGCL). Considering the small size of the adult zebrafish skull and the high risk of death after drilling on the skull, we open the skull with the help of acid-etching and seal the hole with a light curing bond, which could significantly improve the survival rate. After absorbing the dyes for 5 days, almost all the RGCs are labeled. As this method does not need to transect the optic nerve, it is irreplaceable in the research of RGCs survival after optic nerve crush in adult zebrafish. Here, we introduce this method step by step and provide representative results.

We introduce an efficient method to retrograde label retinal ganglion cells (RGCs) in adult zebrafish.

תיוג מדרדר של תאים ברשתית גנגליון מבוגרים דג הזברה עם צבעי ניאון

As retrograde labeling retinal ganglion cells (RGCs) can isolate RGCs somata from dying sites, it has become the gold standard for counting RGCs in RGCs ...

Optical Control of a Neuronal Protein Using a Genetically Encoded Unnatural Amino Acid in Neurons

Photostimulation is a noninvasive way to control biological events with excellent spatial and temporal resolution. New methods are desired to photo-regulate endogenous proteins expressed in their native environment. Here, we present an approach to optically control the function of a neuronal protein directly in neurons using a genetically encoded unnatural amino acid (Uaa). By using an orthogonal tRNA/aminoacyl-tRNA synthetase pair to suppress the amber codon, a photo-reactive Uaa 4,5-dimethoxy-2-nitrobenzyl-cysteine (Cmn) is site-specifically incorporated in the pore of a neuronal protein Kir2.1, an inwardly rectifying potassium channel. The bulky Cmn physically blocks the channel pore, rendering Kir2.1 non-conducting. Light illumination instantaneously converts Cmn into a smaller natural amino acid Cys, activating Kir2.1 channel function. We express these photo-inducible inwardly rectifying potassium (PIRK) channels in rat hippocampal primary neurons, and demonstrate that light-activation of PIRK ceases the neuronal firing due to the outflux of K+ current through the activated Kir2.1 channels. Using in utero electroporation, we also express PIRK in the embryonic mouse neocortex in vivo, showing the light-activation of PIRK in neocortical neurons. Genetically encoding Uaa imposes no restrictions on target protein type or cellular location, and a family of photoreactive Uaas is available for modulating different natural amino acid residues. This technique thus has the potential to be generally applied to many neuronal proteins to achieve optical regulation of different processes in brains. The current protocol presents an accessible procedure for intricate Uaa incorporation in neurons in vitro and in vivo to achieve photo control of neuronal protein activity on the molecular level.

Here, a procedure to selectively activate a neuronal protein with a short pulse of light by genetically encoding a photo-reactive unnatural amino acid into a target neuronal protein expressed in neurons in culture or in vivo is presented.

שליטה אופטית של חלבון עצבי באמצעות חומצות אמינו לא טבעי מקודדים גנטיים בנוירונים

Photostimulation is a noninvasive way to control biological events with excellent spatial and temporal resolution. New methods are desired to ...

Optical Coherence Tomography: Imaging Mouse Retinal Ganglion Cells In Vivo

Structural changes in the retina are common manifestations of ophthalmic diseases. Optical coherence tomography (OCT) enables their identification in vivo&#8212;rapidly, repetitively, and at a high resolution. This protocol describes OCT imaging in the mouse retina as a powerful tool to study optic neuropathies (OPN). The OCT system is an interferometry-based, non-invasive alternative to common post mortem histological assays. It provides a fast and accurate assessment of retinal thickness, allowing the possibility to track changes, such as retinal thinning or thickening. We present the imaging process and analysis with the example of the Opa1delTTAG mouse line. Three types of scans are proposed, with two quantification methods: standard and homemade calipers. The latter is best for use on the peripapillary retina during radial scans; being more precise, is preferable for analyzing thinner structures. All approaches described here are designed for retinal ganglion cells (RGC) but are easily adaptable to other cell populations. In conclusion, OCT is efficient in mouse model phenotyping and has the potential to be used for the reliable evaluation of therapeutic interventions.

Optical Coherence Tomography: Imaging Mouse Retinal Ganglion Cells In Vivo

This manuscript describes a protocol for the in vivo imaging of the mouse retina with high-resolution spectral domain optical coherence tomography (SD-OCT). It focuses on retinal ganglion cells (RGC) in the peripapillary region, with several scanning and quantifying approaches described.

טומוגרפיה אופטית קוהרנטית: הדמיה העכבר גנגליון תאים In Vivo

Structural changes in the retina are common manifestations of ophthalmic diseases. Optical coherence tomography (OCT) enables their identification in ...

In Vivo Two-photon Imaging of Cortical Neurons in Neonatal Mice

Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging methods exist for examining the brain tissue of live newborn mammals. Herein we summarize a protocol for imaging individual cortical neurons in living neonatal mice. This protocol includes the following two methodologies: (1) the Supernova system for sparse and bright labeling of cortical neurons in the developing brain, and (2) a surgical procedure for the fragile neonatal skull. This protocol allows the observation of temporal changes of individual cortical neurites during neonatal stages with a high signal-to-noise ratio. Labeled cell-specific gene silencing and knockout can also be achieved by combining the Supernova with RNA interference and CRISPR/Cas9 gene editing systems. This protocol can, thus, be used for analyzing the developmental dynamics of cortical neurons, molecular mechanisms that control the neuronal dynamics, and changes in neuronal dynamics in disease models.

In Vivo Two-photon Imaging of Cortical Neurons in Neonatal Mice

We present an in vivo two-photon imaging protocol for imaging the cerebral cortex of neonatal mice. This method is suitable for analyzing the developmental dynamics of cortical neurons, the molecular mechanisms that control the neuronal dynamics, and the changes in neuronal dynamics in disease models.

אין ויוו שני הפוטונים הדמיה של נוירונים בקליפת המוח בעכברים Neonatal

Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging ...

Wide-field Single-photon Optical Recording in Brain Slices Using Voltage-sensitive Dye

Wide-field single photon voltage-sensitive dye (VSD) imaging of brain slice preparations is a useful tool to assess the functional connectivity in neural circuits. Due to the fractional change in the light signal, it has been difficult to use this method as a quantitative assay. This article describes special optics and slice handling systems, which render this technique stable and reliable. The present article demonstrates the slice handling, staining, and recording of the VSD-stained hippocampal slices in detail. The system maintains physiological conditions for a long time, with good staining, and prevents mechanical movements of the slice during the recordings. Moreover, it enables staining of slices with a small amount of the dye. The optics achieve high numerical aperture at low magnification, which allows recording of the VSD signal at the maximum frame rate of 10 kHz, with 100 pixel x 100-pixel spatial resolution. Due to the high frame rate and spatial resolution, this technique allows application of the post-recording filters that provide sufficient signal-to-noise ratio to assess the changes in neural circuits.

We introduce a reproducible and stable optical recording method for brain slices using voltage-sensitive dye. The article describes voltage-sensitive dye staining and recording of optical signals using conventional hippocampal slice preparations.

הקלטה אופטית חד-שלמה של פוטון בפרוסות מוח באמצעות שימוש במתח-צבע רגיש

Wide-field single photon voltage-sensitive dye (VSD) imaging of brain slice preparations is a useful tool to assess the functional connectivity in neural ...

Advanced Diffusion Imaging in The Hippocampus of Rats with Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) is the most common type of acquired brain injury. Since patients with traumatic brain injury show a tremendous variability and heterogeneity (age, gender, type of trauma, other possible pathologies, etc.), animal models play a key role in unraveling factors that are limitations in clinical research. They provide a standardized and controlled setting to investigate the biological mechanisms of injury and repair following TBI. However, not all animal models mimic the diffuse and subtle nature of mTBI effectively. For example, the commonly used controlled cortical impact (CCI) and lateral fluid percussion injury (LFPI) models make use of a craniotomy to expose the brain and induce widespread focal trauma, which are not commonly seen in mTBI. Therefore, these experimental models are not valid to mimic mTBI. Thus, an appropriate model should be used to investigate mTBI. The Marmarou weight drop model for rats induces similar microstructural alterations and cognitive impairments as seen in patients who sustain mild trauma; therefore, this model was selected for this protocol. Conventional computed tomography and magnetic resonance imaging (MRI) scans commonly show no damage following a mild injury, because mTBI induces often only subtle and diffuse injuries. With diffusion weighted MRI, it is possible to investigate microstructural properties of brain tissue, which can provide more insight into the microscopic alterations following mild trauma. Therefore, the goal of this study is to obtain quantitative information of a selected region-of-interest (i.e., hippocampus) to follow up disease progression after obtaining a mild and diffuse brain injury.

The overall goal of this procedure is to obtain quantitative microstructural information of the hippocampus in a rat with mild traumatic brain injury. This is done using an advanced diffusion-weighted magnetic resonance imaging protocol and region-of-interest based analysis of parametric diffusion maps.