Name: automated gait analysis in mice with chronic constriction injury
Uploaded: 2017-10-17T14:00:00
Description: Watch this Scientific Journal Video about Automated Gait Analysis in Mice with Chronic Constriction Injury at JoVE.com

This research was supported by Chungnam National University, Korea Institute of Oriental Medicine (KIOM) and a grant of the Korea Health Technology R&#38;D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health &#38; Welfare, Republic of Korea (grant number: HI15C0007).

All experiments were conducted in accordance with the ethical guidelines of the International Association for the Study of Pain and were approved by the Institutional Animal Care and Use Committee at the Chungnam National University (Daejeon, South Korea).
1. Induction of CCI on Sciatic Nerve
<ol>
	<li>House male ICR mice weighing 20 - 25 g under a 12 h light/dark cycle at controlled room temperature (maintained at 20 - 25 &#176;C) and humidity (40 - 60%), with free access to food an...

<ol>
	<li>Loeser, J. D., Treede, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Kyoto+protocol+of+IASP+Basic+Pain+Terminology.">The Kyoto protocol of IASP Basic Pain Terminology.</a> Pain. 137 (3), 473-477 (2008).</li><li>Colloca, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuropathic+pain.">Neuropathic pain.</a> Nat Rev Dis Primers. 3, 17002 (2017).</li><li>Vranken, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+and+treatment+of+neuropathic+pain.">Mechanisms and treatment of neuropathic pain.</a> Cent Nerv Syst Agents Med Chem. 9 (1), 71-78 (2009).</li><li>DeLeo, J. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+a+neuropathic+pain+model:+sciatic+cryoneurolysis+in+the+rat.">Characterization of a neuropathic pain model: sciatic cryoneurolysis in the rat.</a> Pain. 56 (1), 9-16 (1994).</li><li>Kim, S. H., Chung, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+experimental+model+for+peripheral+neuropathy+produced+by+segmental+spinal+nerve+ligation+in+the+rat.">An experimental model for peripheral neuropathy produced by segmental spinal nerve ligation in the rat.</a> Pain. 50 (3), 355-363 (1992).</li><li>Seltzer, Z., Dubner, R., Shir, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+behavioral+model+of+neuropathic+pain+disorders+produced+in+rats+by+partial+sciatic+nerve+injury.">A novel behavioral model of neuropathic pain disorders produced in rats by partial sciatic nerve injury.</a> Pain. 43 (2), 205-218 (1990).</li><li>Bennett, G. J., Xie, Y. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+peripheral+mononeuropathy+in+rat+that+produces+disorders+of+pain+sensation+like+those+seen+in+man.">A peripheral mononeuropathy in rat that produces disorders of pain sensation like those seen in man.</a> Pain. 33 (1), 87-107 (1988).</li><li>Dixon, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+analysis+of+experimental+observations.">Efficient analysis of experimental observations.</a> Annu Rev Pharmacol Toxicol. 20, 441-462 (1980).</li><li>Bonin, R. P., Bories, C., De Koninck, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simplified+up-down+method+(SUDO)+for+measuring+mechanical+nociception+in+rodents+using+von+Frey+filaments.">A simplified up-down method (SUDO) for measuring mechanical nociception in rodents using von Frey filaments.</a> Mol Pain. 10, 26 (2014).</li><li>Chaplan, S. R., Bach, F. W., Pogrel, J. W., Chung, J. M., Yaksh, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+assessment+of+tactile+allodynia+in+the+rat+paw.">Quantitative assessment of tactile allodynia in the rat paw.</a> J Neurosci Methods. 53 (1), 55-63 (1994).</li><li>Chen, H., Du, J., Zhang, Y., Barnes, K., Jia, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishing+a+Reliable+Gait+Evaluation+Method+for+Rodent+Studies.">Establishing a Reliable Gait Evaluation Method for Rodent Studies.</a> J Neurosci Methods. , (2017).</li><li>Kang, D. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antinociceptive+Profile+of+Levo-tetrahydropalmatine+in+Acute+and+Chronic+Pain+Mice+Models:+Role+of+spinal+sigma-1+receptor.">Antinociceptive Profile of Levo-tetrahydropalmatine in Acute and Chronic Pain Mice Models: Role of spinal sigma-1 receptor.</a> Sci Rep. 6, 37850 (2016).</li><li>Huehnchen, P., Boehmerle, W., Endres, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+paclitaxel+induced+sensory+polyneuropathy+with+&amp;#34;Catwalk&amp;#34;+automated+gait+analysis+in+mice.">Assessment of paclitaxel induced sensory polyneuropathy with &amp;#34;Catwalk&amp;#34; automated gait analysis in mice.</a> PLoS One. 8 (10), e76772 (2013).</li><li>Vrinten, D. H., Hamers, F. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term='CatWalk'+automated+quantitative+gait+analysis+as+a+novel+method+to+assess+mechanical+allodynia+in+the+rat;+a+comparison+with+von+Frey+testing.">'CatWalk' automated quantitative gait analysis as a novel method to assess mechanical allodynia in the rat; a comparison with von Frey testing.</a> Pain. 102 (1-2), 203-209 (2003).</li><li>Martinov, T., Mack, M., Sykes, A., Chatterjea, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+changes+in+tactile+sensitivity+in+the+hind+paw+of+mice+using+an+electronic+von+Frey+apparatus.">Measuring changes in tactile sensitivity in the hind paw of mice using an electronic von Frey apparatus.</a> J Vis Exp. (82), e51212 (2013).</li><li>Ferland, C. E., Laverty, S., Beaudry, F., Vachon, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gait+analysis+and+pain+response+of+two+rodent+models+of+osteoarthritis.">Gait analysis and pain response of two rodent models of osteoarthritis.</a> Pharmacol Biochem Behav. 97 (3), 603-610 (2011).</li><li>Mogil, J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypolocomotion,+asymmetrically+directed+behaviors+(licking,+lifting,+flinching,+and+shaking)+and+dynamic+weight+bearing+(gait)+changes+are+not+measures+of+neuropathic+pain+in+mice.">Hypolocomotion, asymmetrically directed behaviors (licking, lifting, flinching, and shaking) and dynamic weight bearing (gait) changes are not measures of neuropathic pain in mice.</a> Mol Pain. 6, 34 (2010).</li><li>Ferreira-Gomes, J., Adaes, S., Castro-Lopes, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+movement-evoked+pain+in+osteoarthritis+by+the+knee-bend+and+CatWalk+tests:+a+clinically+relevant+study.">Assessment of movement-evoked pain in osteoarthritis by the knee-bend and CatWalk tests: a clinically relevant study.</a> J Pain. 9 (10), 945-954 (2008).</li></ol>

Currently, measurement of mechanical allodynia by using von Frey filaments is the most widely used method in pain animal models to demonstrate tactile hypersensitivity. As animal models for neuropathic pain have continued to be developed, the methodology of assessment for sensory function has been also improved8,9,10,15. In those reports, it has been suggested these modifications can provide a ...

Pathological changes of nervous system induced by trauma, metabolic dysfunction, inflammation, infection, ischemia, or autoimmune disease occasionally result in neuropathic pain, which is defined as a pain arising as a direct consequence of a lesion or disease affecting the somatosensory system1. Neuropathic pain is usually unbearable and unfortunately, conventional analgesics generally do not produce sufficient pain relief2. A major feature of neuropathic pain contains spontaneous and stimulation-evoked (i.e., allodynia and hyperalgesia) pains. Allodynia is a nociceptive response that occurs to normally non-painful stimuli, such as light touch or warm stimulation. Hyperalgesia indicates an enhanced pain response to noxious mechanical and/or thermal stimuli3. Although these two symptoms both critically impair the patient&#39;s quality of life, mechanical allodynia evoked by gentle tactile stimulation is the most aggravating symptom because soft contact is difficult to avoid in everyday life.
To investigate the underlying mechanism and new analgesics for the treatment of neuropathic pain, the precise measurement of the pain response is essential. Numerous neuropathic pain animal models have developed nociceptive responses on the hind paw area because of its high accessibility4,5,6,7. Thus, most pain response assessments have been performed on the plantar or dorsal surface of the hind paw by applying mechanical stimuli using special instruments, such as von Frey filaments. One of the most frequently used method is the up and down method described by Dixon8 and the later modified versions9,10. However, very skilled, experienced experimenters are required to perform the von Frey test and the results may be subjective.
The automated gait analysis system can investigate neurological and neuromuscular disorders by measuring various parameters of walking in freely moving rodents. In a variety of nerve injury animal models, the degree of nociception and the antinociceptive effect of several treatments can be evaluated without adding a pain stimulation11,12,13,14. This analysis system can detect static and dynamic gait parameters, such as: paw print area (the area of the complete paw print that contacts with the floor), paw intensity (the average intensity of the contacting paw area), stride length (the distance between successive placements of the same paw), stance phase (the duration of ground contact for a single hind paw), step sequence (the order in which the four paws are placed on the floor), swing (the duration of the swing phase), and swing speed (computed from stride length and swing duration and expressed as pixels per second). This paper demonstrates the use an analysis system and provides a brief comparison of data with the von Frey test using chronic constriction injury (CCI) neuropathic mice.

<table>
	<tbody>
		<tr>
			<td>0.9% Saline</td>
			<td>JW Pharmaceutical</td>
			<td>N/A</td>
			<td>Vehicle for drugs</td>
		</tr>
		<tr>
			<td>1ml syringe</td>
			<td>BD Plastipak</td>
			<td>300013</td>
			<td>Injecting device</td>
		</tr>
		<tr>
			<td>2, 2, 2-tribromoethanol (97% purity)</td>
			<td>Sigma</td>
			<td>T48402</td>
			<td>Anesthetic</td>
		</tr>
		<tr>
			<td>2-methyl-2-buthanol (99% purity)</td>
			<td>Sigma</td>
			<td>152463</td>
			<td>Solvent for 2, 2, 2-tribromoethanol</td>
		</tr>
		<tr>
			<td>Catwalk Automated gait analysis system</td>
			<td>Noldus</td>
			<td>N/A</td>
			<td>Automatic analysis software of aniaml gait</td>
		</tr>
		<tr>
			<td>Chromic catgut (4-0 thickness)</td>
			<td>AILEE</td>
			<td>C442</td>
			<td>Ligature to make chronic constriction injury on the sciatic nerve</td>
		</tr>
		<tr>
			<td>Gabapentin</td>
			<td>Sigma</td>
			<td>Y0001280</td>
			<td>Analgeisc, Used as a positive control drug in this study</td>
		</tr>
		<tr>
			<td>Graefe Forceps</td>
			<td>F.S.T</td>
			<td>11051-10</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Heating Pad</td>
			<td>DAESHIN ELECTRONICS</td>
			<td>M-303AT</td>
			<td>Regulation of body temperature</td>
		</tr>
		<tr>
			<td>ICR Mouse</td>
			<td>Samtaco</td>
			<td>N/A</td>
			<td>Experimental animal</td>
		</tr>
		<tr>
			<td>Mersilk (3-0 thickness)</td>
			<td>ETHICON</td>
			<td>W598H</td>
			<td>Suture material for surgical closure of skin</td>
		</tr>
		<tr>
			<td>Micro-Mosquito</td>
			<td>F.S.T</td>
			<td>13010-12</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Micro-scissors</td>
			<td>F.S.T</td>
			<td>14090-09</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>F.S.T</td>
			<td>12002-12</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Povidone Iodine</td>
			<td>Firson</td>
			<td>N/A</td>
			<td>Disinfectant to prevent infection after surgery</td>
		</tr>
		<tr>
			<td>Scalpel blade</td>
			<td>F.S.T</td>
			<td>10010-00 (#10)</td>
			<td>Surgical instrument to make an incision</td>
		</tr>
		<tr>
			<td>Scalpel handle</td>
			<td>F.S.T</td>
			<td>10003-12 (#3)</td>
			<td>Surgical instrument to make an incision</td>
		</tr>
		<tr>
			<td>Von-Frey filaments</td>
			<td>North Coast</td>
			<td>NC12775-99</td>
			<td>Measurement device to test sensory function for mechanical stimulation</td>
		</tr>
	</tbody>
</table>

automated gait analysis in mice with chronic constriction injury

The von Frey test is a classical method that has been widely used to examine the sensory function of neuropathic pain animals. However, it has some disadvantages such as subjective data and the requirement of a skilled, experienced experimenter. To date, a variety of modifications have improved the von Frey method, but it still has a few limitations. Recent reports have suggested that gait analysis produces more accurate and objective data from the neuropathic animals. This protocol demonstrates how to perform the automated gait analysis to determine the degree of neuropathic pain in mice. After several days of acclimation, the mice were allowed to walk freely on the glass floor to illuminate footprints. Then, quantification of the footprints and gait were performed through video clips with automatic analysis of various walking parameters, such as area of paw print, swing time, angle of paw, etc.
The main purpose of this study is to describe the methodology of automated gait analysis and briefly compare it with data from the classical sensory test using von Frey filament.

We have performed the von Frey test and automated gait analysis in CCI mice until 10 days after CCI surgery. For statistical analysis, repeated measures of two-way analysis of variance (ANOVA) determines the overall effects, and Dunnett&#39;s post-hoc analysis was performed to determine the p-value among the experimental groups.
The results shown in Figure 1 indicate the time course of the ...

Watch this Scientific Journal Video about Automated Gait Analysis in Mice with Chronic Constriction Injury at JoVE.com

Automated Gait Analysis in Mice with Chronic Constriction Injury

The precise assessment of pain response in a neuropathic animal model is critical to investigate the pathophysiology of pain diseases and develop new analgesics. We present a sensitive and objective method to determine the sensory function of the rodent hind paw by an automated gait analysis system.

The von Frey test is a classical method that has been widely used to examine the sensory function of neuropathic pain animals. However, it has some ...

The overall goal of this procedure is to analyze mechanical allodynia of mice with a chronic constriction injury using an automated gait analysis system. This method can help answer key questions in the pain research field by measuring sensory function after peripheral nerve injury in rodents. The main advantage of this technique is that the analysis system is quick and easy to use and it also automatically scores various gait parameters.For this study, house male ICR mice weighing 20 to 25 grams under standard conditions for at least one week. Select mice based on their appearance and behavior. Do not use mice that exhibit abnormal appearances or behavior such as hair loss, scarring and less movement.Using the selected mice, starting five days before the surgery collect automated gait data on a daily basis to have a baseline measurement. One day before the surgery perform the Von Frey test with a one gram filament on a hind paw to get a baseline response. Balance the responses between the injury group and the sham group.On each test day bring mice to the behavioral test room and acclimate the mice in their own home cage for at least 30 minutes before the test. Every other day after the surgery, measure mechanical allodynia using a Von Frey test. Put the mouse in a clean transparent acrylic box on a metal mesh floor and let it acclimate to the box for 30 minutes.Next, gently apply a one gram Von Frey filament to the plantar surface of the ipsilateral hind paw until the filament bends. Repeat this pattern of stimulation 10 times observing for paw withdrawals. Wait at least 10 seconds between stimulations.Record the number of withdrawals and score their frequency for analysis. Every other day, also perform the gait analysis test which must be done in the dark. Again, acclimate the mice to the test room in their home cage for at least 30 minutes.To set up the gait analysis device go to the software control. Under the setup tab set the walkway length to 30 centimeters, set the maximum run duration to five seconds and set the maximum run variation to 50%Next, select a registered camera from the setup tab of the program menu and then select open acquisition from the acquire tab. Following the status message, click the snap background button to take a background picture of the empty walkway.Now place a mouse onto the walkway and allow it to acclimate to the device for 10 minutes. The apparatus should always be washed with alcohol between mice. After the mouse has acclimated to the device, click the start acquisition button.The recording starts automatically according to the movement of the mouse. When the mouse clearly walks across the walkway, the program will automatically classify the compliant runs with a green icon. If the software fails to detect the footprints, a red icon will light up.After collecting at least five compliant runs select the classify runs option from the acquire tab of the program menu. Select which run should be analyzed and click the auto classify button. The results are automatically saved.To view the results click on view run statistics from the analyze menu. The Von Frey test and automated gait analysis were used to assess mice that underwent the CCI surgery on 10 consecutive days post-operatively. The frequency of paw withdrawal increased two days after the surgery and was sustained for 10 days.This effect could be significantly reduced by daily post-operative injections of gabapentin. Using the gait analysis software the size of the left and right hind paw prints could be compared. Normally the areas are the same which is indicated by a 50%value.The CCI surgery had a significant effect on paw print and that effect could be significantly reduced using gabapentin. The gait analysis software is also able to pick up on the change of single stance durations when the mouse is weight-bearing on just one hind paw. This is calculated and shown as a percent change.This metric shows the same effect for the CCI surgery and gabapentin treatments. After watching this video you should have a good understanding of how to operate and analyze automated gait analysis systems to investigate the pathophysiology of neuropathic pain in animal models like chronic constriction injury.

automated-gait-analysis-in-mice-with-chronic-constriction-injury

Research

JoVE Journal

Neuroscience

Automated Sholl Analysis of Digitized Neuronal Morphology at Multiple Scales

Neuronal morphology plays a significant role in determining how neurons function and communicate1-3. Specifically, it affects the ability of neurons to receive inputs from other cells2 and contributes to the propagation of action potentials4,5. The morphology of the neurites also affects how information is processed. The diversity of dendrite morphologies facilitate local and long range signaling and allow individual neurons or groups of neurons to carry out specialized functions within the neuronal network6,7. Alterations in dendrite morphology, including fragmentation of dendrites and changes in branching patterns, have been observed in a number of disease states, including Alzheimer's disease8, schizophrenia9,10, and mental retardation11. The ability to both understand the factors that shape dendrite morphologies and to identify changes in dendrite morphologies is essential in the understanding of nervous system function and dysfunction.
Neurite morphology is often analyzed by Sholl analysis and by counting the number of neurites and the number of branch tips. This analysis is generally applied to dendrites, but it can also be applied to axons. Performing this analysis by hand is both time consuming and inevitably introduces variability due to experimenter bias and inconsistency. The Bonfire program is a semi-automated approach to the analysis of dendrite and axon morphology that builds upon available open-source morphological analysis tools. Our program enables the detection of local changes in dendrite and axon branching behaviors by performing Sholl analysis on subregions of the neuritic arbor. For example, Sholl analysis is performed on both the neuron as a whole as well as on each subset of processes (primary, secondary, terminal, root, etc.) Dendrite and axon patterning is influenced by a number of intracellular and extracellular factors, many acting locally. Thus, the resulting arbor morphology is a result of specific processes acting on specific neurites, making it necessary to perform morphological analysis on a smaller scale in order to observe these local variations12.
The Bonfire program requires the use of two open-source analysis tools, the NeuronJ plugin to ImageJ and NeuronStudio. Neurons are traced in ImageJ, and NeuronStudio is used to define the connectivity between neurites. Bonfire contains a number of custom scripts written in MATLAB (MathWorks) that are used to convert the data into the appropriate format for further analysis, check for user errors, and ultimately perform Sholl analysis. Finally, data are exported into Excel for statistical analysis. A flow chart of the Bonfire program is shown in Figure 1.

We have developed a computer program to analyze neuronal morphology. In combination with two existing open source analysis tools, our program performs Sholl analysis and determines the number of neurites, branch points, and neurite tips. The analyses are performed so that local changes in neurite morphology can be observed.

Neuronal morphology plays a significant role in determining how neurons function and communicate1-3.  Specifically, it affects the ability of neurons to ...

Spectral Confocal Imaging of Fluorescently tagged Nicotinic Receptors in Knock-in Mice with Chronic Nicotine Administration

Ligand-gated ion channels in the central nervous system (CNS) are implicated in numerous conditions with serious medical and social consequences. For instance, addiction to nicotine via tobacco smoking is a leading cause of premature death worldwide (World Health Organization) and is likely caused by an alteration of ion channel distribution in the brain1. Chronic nicotine exposure in both rodents and humans results in increased numbers of nicotinic acetylcholine receptors (nAChRs) in brain tissue1-3. Similarly, alterations in the glutamatergic GluN1 or GluA1 channels have been implicated in triggering sensitization to other addictive drugs such as cocaine, amphetamines and opiates4-6.

Consequently, the ability to map and quantify distribution and expression patterns of specific ion channels is critically important to understanding the mechanisms of addiction. The study of brain region-specific effects of individual drugs was advanced by the advent of techniques such as radioactive ligands. However, the low spatial resolution of radioactive ligand binding prevents the ability to quantify ligand-gated ion channels in specific subtypes of neurons. 

Genetically encoded fluorescent reporters, such as green fluorescent protein (GFP) and its many color variants, have revolutionized the field of biology7.By genetically tagging a fluorescent reporter to an endogenous protein one can visualize proteins in vivo7-10. One advantage of fluorescently tagging proteins with a probe is the elimination of antibody use, which have issues of nonspecificity and accessibility to the target protein. We have used this strategy to fluorescently label nAChRs, which enabled the study of receptor assembly using F&ouml;rster Resonance Energy Transfer (FRET) in transfected cultured cells11.More recently, we have used the knock-in approach to engineer mice with yellow fluorescent protein tagged &alpha;4 nAChR subunits (&alpha;4YFP), enabling precise quantification of the receptor ex vivo at submicrometer resolution in CNS neurons via spectral confocal microscopy12. The targeted fluorescent knock-in mutation is incorporated in the endogenous locus and under control of its native promoter, producing normal levels of expression and regulation of the receptor when compared to untagged receptors in wildtype mice. This knock-in approach can be extended to fluorescently tag other ion channels and offers a powerful approach of visualizing and quantifying receptors in the CNS.

In this paper we describe a methodology to quantify changes in nAChR expression in specific CNS neurons after exposure to chronic nicotine. Our methods include mini-osmotic pump implantation, intracardiac perfusion fixation, imaging and analysis of fluorescently tagged nicotinic receptor subunits from &alpha;4YFP knock-in mice (Fig. 1). We have optimized the fixation technique to minimize autofluorescence from fixed brain tissue.We describe in detail our imaging methodology using a spectral confocal microscope in conjunction with a linear spectral unmixing algorithm to subtract autofluoresent signal in order to accurately obtain &alpha;4YFP fluorescence signal. Finally, we show results of chronic nicotine-induced upregulation of &alpha;4YFP receptors in the medial perforant path of the hippocampus.

We have developed a novel technique of quantifying nicotinic acetylcholine receptor changes within subcellular regions of specific subtypes of CNS neurons to better understand the mechanisms of nicotine addiction by using a combination of approaches including fluorescent protein tagging of the receptor using the knock-in approach and spectral confocal imaging.

Ligand-gated ion channels in the central nervous system (CNS) are implicated in numerous conditions with serious medical and social consequences.  For ...

Sagittal Plane Kinematic Gait Analysis in C57BL/6 Mice Subjected to MOG35-55 Induced Experimental Autoimmune Encephalomyelitis

Kinematic gait analysis in the sagittal plane has frequently been used to characterize motor deficits in multiple sclerosis (MS). We describe the application of these techniques to identify gait deficits in a mouse model of MS, known as experimental autoimmune encephalomyelitis (EAE). Paralysis and motor deficits in mice subjected to EAE are typically assessed using a clinical scoring scale. However, this scale yields only ordinal data that provides little information about the precise nature of the motor deficits. EAE disease severity has also been assessed by rotarod performance, which provides a measure of general motor coordination. By contrast, kinematic gait analysis of the hind limb in the sagittal plane generates highly precise information about how movement is impaired. To perform this procedure, reflective markers are placed on a hind limb to detect joint movement while a mouse is walking on a treadmill. Motion analysis software is used to measure movement of the markers during walking. Kinematic gait parameters are then derived from the resultant data. We show how these gait parameters can be used to quantify impaired movements of the hip, knee, and ankle joints in EAE. These techniques may be used to better understand disease mechanisms and identify potential treatments for MS and other neurodegenerative disorders that impair mobility.

Kinematic gait analysis in the sagittal plane yields highly precise information about how movement is executed. We describe the application of these techniques to identify gait deficits for mice subjected to autoimmune-mediated demyelination. These methods may also be used to characterize gait deficits for other mouse models featuring impaired locomotion.

Kinematic gait analysis in the sagittal plane has frequently been used to characterize motor deficits in multiple sclerosis (MS). We describe the ...

Chronic Implantation of Whole-cortical Electrocorticographic Array in the Common Marmoset

Electrocorticography (ECoG) allows the monitoring of electrical field potentials from the cerebral cortex with high spatiotemporal resolution. Recent development of thin, flexible ECoG electrodes has enabled conduction of stable recordings of large-scale cortical activity. We have developed a whole-cortical ECoG array for the common marmoset. The array continuously covers almost the entire lateral surface of cortical hemisphere, from the occipital pole to the temporal and frontal poles, and it captures whole-cortical neural activity in one shot. This protocol describes a chronic implantation procedure of the array in the epidural space of the marmoset brain. Marmosets have two advantages regarding ECoG recordings, one being the homologous organization of anatomical structures in humans and macaques, including frontal, parietal, and temporal complexes. The other advantage is that the marmoset brain is lissencephalic and contains a large number of complexes, which are more difficult to access in macaques with ECoG, that are exposed to the brain surface.These features allow direct access to most cortical areas beneath the surface of the brain. This system provides an opportunity to investigate global cortical information processing with high resolutions at a sub-millisecond order in time and millimeter order in space.

We have developed a whole-cortical electrocorticographic array for the common marmoset that continuously covers almost the entire lateral surface of cortex, from the occipital pole to the temporal and frontal poles. This protocol describes a chronic implantation procedure of the array in the epidural space of the marmoset brain.

Electrocorticography (ECoG) allows the monitoring of electrical field potentials from the cerebral cortex with high spatiotemporal resolution. Recent ...

Automated Gait Analysis to Assess Functional Recovery in Rodents with Peripheral Nerve or Spinal Cord Contusion Injury

Peripheral and central nerve injuries are mostly studied in rodents, especially rats, given the fact that these animal models are both cost-effective and a lot of comparative data has been published in the literature. This includes a multitude of assessment methods to study functional recovery following nerve injury and repair. Besides evaluation of nerve regeneration by means of histology, electrophysiology, and other in vivo and in vitro assessment techniques, functional recovery is the most important criterion to determine the degree of neural regeneration. Automated gait analysis allows recording of a vast quantity of gait-related parameters such as Paw Print Area and Paw Swing Speed as well as measures of inter-limb coordination. Additionally, the method provides digital data of the rats&#8217; paws after neuronal damage and during nerve regeneration, adding to our understanding of how peripheral and central nervous injuries affect their locomotor behavior. Besides the predominantly used sciatic nerve injury model, other models of peripheral nerve injury such as the femoral nerve can be studied by means of this method. In addition to injuries of the peripheral nervous systems, lesions of the central nervous system, e.g., spinal cord contusion can be evaluated. Valid and reproducible data assessment is strongly dependent on meticulous adjustment of the hard- and software settings prior to data acquisition. Additionally, proper training of the experimental animals is of crucial importance. This work aims to illustrate the use of computerized automated gait analysis to assess functional recovery in different animal models of peripheral nerve injury as well as spinal cord contusion injury. It also emphasizes the method&#8217;s limitations, e.g., evaluation of nerve regeneration in rats with sciatic nerve neurotmesis due to limited functional recovery. Therefore, this protocol is thought to help researchers interested in peripheral and central nervous injuries to assess functional recovery in rodent models.

Automated gait analysis is a feasible tool to evaluate functional recovery in rodent models of peripheral nerve injury and spinal cord contusion injury. While it requires only one setup to assess locomotor function in various experimental models, meticulous hard- and soft-ware adjustment and training of the animals is highly important.

Peripheral and central nerve injuries are mostly studied in rodents, especially rats, given the fact that these animal models are both cost-effective and ...

Comprehensive Understanding of Inactivity-Induced Gait Alteration in Rodents

It is well known that disuse affects neural systems and that joint motions become altered; however, which outcomes properly exhibit these characteristics is still unclear. The present study describes a motion analysis approach that utilizes three-dimensional (3D) reconstruction from video captures. Using this technology, disuse-evoked alterations of walking performances were observed in rodents exposed to a simulated microgravity environment by unloading their hindlimb by their tail. After 2 weeks of unloading, the rats walked on a treadmill, and their gait motions were captured with four charge-coupled device (CCD) cameras. 3D motion profiles were reconstructed and compared to those of control subjects using the image processing software. The reconstructed outcome measures successfully portrayed distinct aspects of distorted gait motion: hyperextension of the knee and ankle joints and higher position of the hip joints during the stance phase. Motion analysis is useful for several reasons. First, it enables quantitative behavioral evaluations instead of subjective observations (e.g., pass/fail in certain tasks). Second, multiple parameters can be extracted to fit specific needs once the fundamental datasets are obtained. Despite hurdles for broader application, the disadvantages of this method, including labor intensity and cost, may be alleviated by determining comprehensive measurements and experimental procedures.

The present protocol describes three-dimensional motion tracking/evaluation to depict gait motion alteration of rats after exposure to a simulated disuse environment.

It is well known that disuse affects neural systems and that joint motions become altered; however, which outcomes properly exhibit these characteristics ...

Electromagnetic Controlled Closed-Head Model of Mild Traumatic Brain Injury in Mice

Highly reproducible animal models of traumatic brain injury (TBI), with well-defined pathologies, are needed for testing therapeutic interventions and understanding the mechanisms of how a TBI alters brain function. The availability of multiple animal models of TBI is necessary to model the different aspects and severities of TBI seen in people. This manuscript describes the use of a midline closed head injury (CHI) to develop a mouse model of mild TBI. The model is considered mild because it does not produce structural brain lesions based on neuroimaging or gross neuronal loss. However, a single impact creates enough pathology that cognitive impairment is measurable at least 1 month after injury. A step-by-step protocol to induce a CHI in mice using a stereotaxically guided electromagnetic impactor is defined in the paper. The benefits of the mild midline CHI model include the reproducibility of the injury-induced changes with low mortality. The model has been temporally characterized up to 1 year after the injury for neuroimaging, neurochemical, neuropathological, and behavioral changes. The model is complementary to open skull models of controlled cortical impact using the same impactor device. Thus, labs can model both mild diffuse TBI and focal moderate-to-severe TBI with the same impactor.

The protocol describes mild traumatic brain injury in a mouse model. In particular, a step-by-step protocol to induce a mild midline closed head injury and the characterization of the animal model is fully explained.

Highly reproducible animal models of traumatic brain injury (TBI), with well-defined pathologies, are needed for testing therapeutic interventions and ...

A Spinal Cord Injury Contusion Device for Accurate Mouse Models

Automated Impactor for Contusive Spinal Cord Injury Model in Mice

Spinal cord injury (SCI) due to traumatic injuries such as car accidents and falls is associated with permanent spinal cord dysfunction. Creation of contusion models of spinal cord injury by impacting the spinal cord results in similar pathologies to most spinal cord injuries in clinical practice. Accurate, reproducible, and convenient animal models of spinal cord injury are essential for studying spinal cord injury. We present a novel automated spinal cord injury contusion device for mice, the Guangzhou Jinan University smart spinal cord injury system, that can produce spinal cord injury contusion models with accuracy, reproducibility, and convenience. The system accurately produces models of varying degrees of spinal cord injury via laser distance sensors combined with an automated mobile platform and advanced software. We used this system to create three levels of spinal cord injury mice models, determined their Basso mouse scale (BMS) scores, and performed behavioral as well as staining assays to demonstrate its accuracy and reproducibility. We show each step of the development of the injury models using this device, forming a standardized procedure. This method produces reproducible spinal cord injury contusion mice models and reduces human manipulation factors via convenient handling procedures. The developed animal model is reliable for studying spinal cord injury mechanisms and associated treatment approaches.

Author Spotlight: Insight Into Innovations in Spinal Cord Injury Research

Presented here is a novel automated spinal cord injury contusion device for mice, which can accurately produce spinal cord injury contusion models with varying degrees.

Spinal cord injury (SCI) due to traumatic injuries such as car accidents and falls is associated with permanent spinal cord dysfunction. Creation of ...

Assessing Tuina Therapy&#039;s Pain Relief in Chronic Constriction Rats

Characteristics of Pain Changes in Rats with Nerve Injury Within 24 hours After One-Time Tuina Intervention

Tuina, as an external treatment method of traditional Chinese medicine, has been proven to have an analgesic effect on peripheral neuropathic pain (pNP) in clinical and basic research. However, the optimal time point for the analgesic effect of tuina may vary according to different injury sensations, affecting the exploration of the initiation mechanism of tuina analgesia. 
The research used minor chronic constriction injury (minor CCI) model rats to simulate pNP and used the intelligent tuina manipulation simulator to simulate the three methods (point-pressing, plucking, and kneading) and three acupoints (Yinmen BL37, Chengshan BL57, and Yanglingquan GB34) for performing tuina therapy. The study evaluated the changes in pain within 24 h and the optimal time point for the efficacy of tuina analgesia in rats with minor CCI models by testing cold sensitivity threshold (CST), mechanical withdrawal threshold (MWT), and thermal withdrawal latency (TWL). Furthermore, the study evaluated IL-10 and TNF-&#945; expression changes through Elisa detection. The results show that tuina has both immediate and sustained analgesic effects. For the three different injury sensitivity thresholds of CST, MWT, TWL, and two cytokines of IL-10 and TNF-&#945;, the analgesic efficacy of tuina within 24 h after intervention is significantly different at different time points.

Author Spotlight: Exploring the Initiation Mechanism of &#039;Three-Method and Three-Acupoint&#039; Tuina Analgesia in Rats with Nerve Injury

We present a protocol using the tuina manipulation simulator to perform the "Three-Manipulation and Three-Acupoint" tuina therapy for minor chronic constriction injury rats and evaluate the effective analgesic time points of tuina within 24 h by testing pain changes through behavioral analysis and changes in inflammatory factor expression using enzyme-linked immunosorbent assay.

Tuina, as an external treatment method of traditional Chinese medicine, has been proven to have an analgesic effect on peripheral neuropathic pain (pNP) ...

Establishing the Mouse Model for Trigeminal Neuropathic Pain

Chronic Constriction Injury of the Distal Infraorbital Nerve (DIoN-CCI) in Mice to Study Trigeminal Neuropathic Pain

Animal models remain necessary tools to study neuropathic pain. This manuscript describes the distal infraorbital nerve chronic constriction injury (DIoN-CCI) model to study trigeminal neuropathic pain in mice. This includes the surgical procedures to perform the chronic constriction injury and the postoperative behavioral tests to evaluate the changes in spontaneous and evoked behavior that are signs of ongoing pain and mechanical allodynia. The methods and behavioral readouts are similar to the infraorbital nerve chronic constriction injury (IoN-CCI) model in rats. However, important changes are necessary for the adaptation of the IoN-CCI model to mice. First, the intra-orbital approach is replaced by a more rostral approach with an incision between the eye and the whisker pad. The IoN is thus ligated distally outside the orbital cavity. Secondly, due to the higher locomotor activity in mice, allowing rats to move freely in small cages is replaced by placing mice in custom-designed and constructed restraining devices. After DIoN ligation, mice exhibit changes in spontaneous behavior and in response to von Frey hair stimulation that are similar to those in IoN-CCI rats, i.e., increased directed face grooming and hyperresponsiveness to von Frey hair stimulation of the IoN territory.

Author Spotlight: Utilizing Infraorbital Nerve Ligation in Mice for Investigating Trigeminal Neuropathic Pain and Treatment Strategies

Chronic constriction injury of the distal infraorbital nerve in mice induces changes in spontaneous behavior (increased face grooming activity) and nocifensive behavior in response to tactile stimulation (hyperresponsiveness to von Frey hair stimulation) that are signs of ongoing pain and allodynia and serves as a model for trigeminal neuropathic pain.

Animal models remain necessary tools to study neuropathic pain. This manuscript describes the distal infraorbital nerve chronic constriction injury ...