This work was supported by the German Federal Ministry of Education and Research (BMBF DysTract to C.W.I.) and by the Interdisciplinary Center for Clinical Research (IZKF) at the University of W&#252;rzburg (N-362 to C.W.I.; Z2-CSP3 to L.R.). In addition, this project has received funding from the European Union&#39;s Horizon 2020 research and innovation programme under the EJP RD COFUND-EJP N&#176; 825575 (EurDyscover to J.V.), and from the VERUM Foundation. Moreover C.W.I. is funded by the Deutsche Forschungsgemeinschaft (DFG, German Reseach Foundation) Project-ID 424778381-TRR 295, by the&#160;Deutsche Stiftung Neurologie and ParkinsonFonds. L.R. is additionally supported by the Dystonia Medical Reseach Foundation.
The authors thank Keali R&#246;hm, Veronika Senger, Heike Menzel and Louisa Frie&#223; for their technical assistance as well as Helga Br&#252;nner for the animal care.

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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reproducible+mouse+sciatic+nerve+crush+and+subsequent+assessment+of+regeneration+by+whole+mount+muscle+analysis.">Reproducible mouse sciatic nerve crush and subsequent assessment of regeneration by whole mount muscle analysis.</a> Journal of Visualized Experiments. (60), e3606 (2012).</li><li>Savastano, L. E., 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=Sciatic+nerve+injury:+a+simple+and+subtle+model+for+investigating+many+aspects+of+nervous+system+damage+and+recovery.">Sciatic nerve injury: a simple and subtle model for investigating many aspects of nervous system damage and recovery.</a> Journal of Neuroscience Methods. 227, 166-180 (2014).</li><li>Menorca, R. M., Fussell, T. S., Elfar, J. 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The authors have nothing to disclose.

This behavioral assessment protocol provides an overview of advantages and disadvantages as well as possible readouts of the selected behavioral test battery in a rodent model after sciatic nerve crush injury. 
To obtain a comparative outcome of the sciatic nerve crush injury, a consistent crush technique is mandatory. The use of a non-serrated clamp (Ultra Fine Hemostat) instead of forceps can improve the consistency of the crush. Use the same clamp as well as the same crush position to guarantee equal nerve compression. The exclusive use of the clamp for the crush injury and handling of the clamp with care improves consistency. Also, perform the procedure of the crush injury with care. Additional damage to the nerve during surgery such as unwanted traction of the nerve can lead to undesired side effects like automutilation. Therefore, a careful nerve preparation as well as an administration of a pain reliever for a minimum of two days is recommended. 
Multifactorial assessment of motor behavior can characterize the phenotype after nerve crush injury in rats at various levels. We used the OFT, CatWalk XT gait analysis, beam walking task and ladder rung walking task. A blinded experimental procedure and data analysis to experimental groups is essential for these experiments. Before behavior assessment, animals were acclimated in the testing room under testing conditions for at least 30 minutes. All the behavioral tests applied herein have the advantage that food or water deprivation are not required. The same group set of animals were used in all described behavioral tests. A maximum of two different behavioral tests per day were performed for each animal. If behavioral tests are performed in regular intervals, pay attention of a comparable procedure, like performing the test in the same animal order and at the same time of the day. A further important aspect for behavioral analysis is the day-night cycle of rats. Consider a reversed day-night cycle to obtain more natural and higher levels of activity at the day cycle (dark cycle). This has to be considered especially for measurement of spontaneous behavior, like the OFT. In this experiment, a reversed day-night cycle could not be implemented, but an adequate acclimatization to the testing conditions was ensured. A perfect illumination is essential for high-resolution videos for the beam walking task and the ladder rung walking task. This high video quality cannot be reached when performing experiments in the dark. 
The assessment of gait requires a continuous task performance. The first important aspect of a continuous task performance is to convince the animals to cross the setup. To increase the motivation, place small food pellets (45 mg) at the end of the setup. In order for animals to get familiarized with the food pellets, the pellets should be fed to them prior to testing. Also, a goal box at the end of the setup can be helpful. The setup of the CatWalk already includes a goal box, but rats sometimes hesitate to enter the goal box. Alternatively, you can add a small cage into the goal box, but the home cage from rats does not fit into the goal box. Let the rat habituate in the cage for a few minutes before acquisition. Additionally, another rat from the same home cage may be placed into the goal box or into the cage inside the goal box. Make sure that the second rat remains in the box and does not block the entrance to the goal box. Furthermore, it is also possible to remove the goal box from the CatWalk system and to place the rat home cage at the end of the walkway, which allows the rat to enter their "home territory" after each run. For the setup of the beam walking task and the ladder rung walking task, we recommend to add a goal box or the home cage at the end of the setup. To ensure consistency, the CatWalk, the beam walking task, and the ladder rung walking task should be performed at least once a week with six to ten runs.
Although not every analysis yielded significant differences in this study, consider that an inclusion of genetically modified animals or treatment groups could produce valuable data that can distinguish between groups from the same behavioral tests. 
The nerve crush injury had no effect on the locomotor activity of the rat, which was measured in a five minutes OFT. Catwalk XT gait analysis is a more objective and sensitive tool to analyze gait, paw and toe placement. After an intensive training, the rats learn to cross the walkway of the CatWalk XT apparatus to the default settings. The nerve injury does not reduce the ability of the rats to cross the walkway. The automatic computation of various parameters presents the data objectively. Additional information can be gained by using the "Interactive Footprint Measurements" module and indeed, these analyzes yielded significant differences in various parameters of toe spread, print length and paw angle to body axis comparing rats with and without nerve injury.
Rats can be trained easily for the beam walking task. Differences in the latency time to cross the beam and in the number of foot slips per step of the nerve-injured hindlimb were detected by comparing na&#239;ve with crush-injured rats. A disadvantage of analyzing nerve-injured rats with the beam walking task is the size of the beam. Within the first two weeks after the sciatic nerve crush injury, the rats need assistance to cross the beam as their balance is impaired. Although some rats may be capable of crossing the beam, the risk of injuries caused by a fall is high. Nerve-crushed animals should therefore be assisted to cross the beam for the first two weeks after sciatic nerve crush injury or longer, if necessary. However, it is difficult to compare runs with and without assistance. Also, the motor balance is an important parameter assessed by the beam walking task. We considered this parameter not to be relevant to our nerve crush rat model. Therefore, scores described by Ohwatashi et al. and Johansson &amp; Ohlsson could not be used and runs with an incomplete beam traverse were excluded for data analysis18,19.
The 7-category scale from Metz et al. can analyze both fore- and hindlimbs and distinguish between different severity levels of errors of all limbs during the ladder rung walking task16,17. By analyzing the most prominent errors, which include the categories from 0 to 2, no differences of errors per step could be detected in the hindlimb when comparing nerve-injured wt rats with na&#239;ve wt rats. Furthermore, the latency time of traversing the ladder rung apparatus did not differ between nerve-injured wt rats and wt na&#239;ve rats. Deep learning models could improve and speed up data analysis of the ladder rung walking task through an automated approach. 
It is important to mention that the nerve crush injury as well as all described behavioral tests can easily translated to mice, by adapting the settings and sizes of the setups. The use of mice as a model organism has the beneficial effect that transgenic models for many human diseases exist.

Rodents are excellent model organisms to deepen the understanding of human diseases1,2 by testing hypotheses on multiple biological levels. One fundamental biological level for the characterization of rodent models is the phenotype level, measured by behavioral assessments. Depending on the animal model and the scientific research question, the selection of a powerful and reliable behavioral test battery is essential to cover a wide range of behavioral aspects such as for animal models of Parkinson&#39;s disease and dystonia3,4,5,6.
The sciatic nerve is the largest nerve in the human body with motor as well as sensory fibers. Injuries of the sciatic nerve can result easily from a variety of events such as traffic accidents and surgeries7,8. Therefore, research activities using rodent models with sciatic nerve injuries, are of translationally relevant value. Even though the translational aspect of nerve regeneration from rat to human has to be regarded critically9, the sciatic nerve crush injury (axonotmesis) in rodent models is a commonly used method to analyze degeneration and regeneration processes of peripheral nerves10,11. In case of a crush injury the nerve is not completely transected. It damages the axon, resulting in conduction block directly after crush injury followed by regenerative processes 4,12,13.
Moreover, in dystonia research, the unilateral sciatic nerve crush injury is an established method to trigger dystonia-like movements (DLM) in genetically predisposed dystonia rodent models, which do not show DLM per se4,14. It is assumed that the peripheral nerve trauma disturbs the sensorimotor integration by affecting the sciatic nerve fibers, which are responsible for motor and sensory functions15.
We here provide a detailed description for a standardized crush injury of the sciatic nerve and a battery of motor behavior assessments that is composed of the open field test (OFT), CatWalk XT gait analysis, beam walking task and ladder rung walking task in na&#239;ve wild type (wt) rats (n= 8-9) and wt rats five weeks after unilateral sciatic nerve crush injury (n= 10). The OFT provides information about the general locomotor activity, while a detailed gait analysis is achieved by the automated gait analysis system CatWalk XT. The beam walking task is used to assess the motor coordination by evaluating the time to cross the beam and the number of foot placement errors. For gait performance analysis the ladder rung walking task gives information about foot or paw placement and errors on a horizontal ladder rung apparatus with a constant but irregular rung pattern.

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			<td>Bayer Vital GmbH</td>
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			<td>self made</td>
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			<td>JVC</td>
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			<td>Noldus</td>
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			<td>&#160;setup and software</td>
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			<td>Dr. Wilfried M&#252;ller GmbH</td>
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			<td>Fine Science Tools</td>
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			<td>Dumont #5 forceps</td>
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			<td>Noldus</td>
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			<td>Forceps 160 mm</td>
			<td>Hartenstein</td>
			<td>PZ09</td>
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			<td>Dr. Wilfried M&#252;ller GmbH</td>
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			<td>Goal box for ladder rung walking task apparatus</td>
			<td>self made</td>
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			<td>Wahl GmbH</td>
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			<td>self made</td>
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			<td>self made</td>
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			<td>Spacer for ladder rung walking task apparatus</td>
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			<td>Suture Silkam 4/0 DS 19</td>
			<td>B. Braun</td>
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			<td>Ultra fine hemostats (non-serrated clamp)</td>
			<td>Fine Science Tools</td>
			<td>13020-12</td>
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</table>

multifactorial assessment of motor behavior in rats after unilateral sciatic nerve crush injury

The induction of a peripheral nerve injury is a widely used method in neuroscience for the assessment of repair and pain mechanisms among others. In addition, in the research field of movement disorders, sciatic crush injury has been employed to trigger a dystonia-like phenotype in genetically predisposed DYT-TOR1A rodent models of dystonia. To achieve consistent, reproducible and comparable results after a sciatic nerve crush injury, a standardized method for inducing the nerve crush is essential, in addition to a standardized phenotypical characterization. Attention must be paid not only to the specific assortment of behavioral tests, but also to the technical requirements, the correct execution and consecutive data analysis. This protocol describes in detail how to perform a sciatic nerve crush injury and provides a behavioral test battery for the assessment of motor deficits in rats that includes the open field test, the CatWalk XT gait analysis, the beam walking task, and the ladder rung walking task.

The representative results of the five minutes OFT show that the nerve crush injury five weeks post surgery has no effect on the locomotor activity (Figure 1).
Gait analysis with the CatWalk XT system (Figure 2) generates many different parameters. Selective parameters were statistically analyzed by comparing wt na&#239;ve rats with nerve-injured wt rats five weeks after the nerve crush (Figure 2D). Significant alterations could be detected for the run average speed, the stride length and the print area of the nerve-injured (right) hind paw. A more detailed analysis of the nerve-injured hind paw was performed with the &#34;Interactive Footprint Measurements&#34; module. A significant reduction of the parameters toe spread, intermediate toe spread and print length were observed in nerve-injured wt rats compared to wt na&#239;ve rats. In addition, the paw angle body axis and the paw angle movement vector significantly differ when comparing nerve-injured wt rats with wt na&#239;ve rats (Figure 2E).
Figure 3 presents data of motor coordination obtained through beam walking task assessment. Nerve-injured wt rats showed a significantly increased latency time to cross the beam compared to wt na&#239;ve rats five weeks post injury (Figure 3B). As an additional read out of the beam walking task, full slips and half slips of the nerve-injured hindlimb were counted and considered as an error for statistical analysis. The percentage of errors per step of the nerve-injured (right) hindlimb was significantly increased in nerve-injured wt rats compared to wt na&#239;ve rats.
Representative data of the ladder rung walking task (Figure 4) does not show significant alterations in the latency time to cross the walkway of the ladder rung apparatus (Figure 4C) or in the percentage of errors per step of the nerve-injured (right) hindlimb (Figure 4D). The analysis of the error percentage per step of the nerve-injured hindlimb considered only the score from 0 to 2 of the 7-category scale from Metz et al. The distribution of all score categories per step from the 7-category scale of the nerve-injured hindlimb and the non-nerve-injured (left) hindlimb is illustrated in Figure 4E.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/62606/62606fig01.jpg" /> 
Figure 1: Assessment of locomotor activity during open field test. (A) Picture of the open field test setup. Selected picture subtracted from a recorded video during open field test showing a rat in the open field arena without (B) and with (C) tracking. (D) The velocity during a five minutes open field test recording was investigated in wt na&#239;ve rats and wt rats five weeks after nerve crush injury. Data are shown as mean &#177; SEM. Statistical analysis was performed using the unpaired t test of the normally distributed data. <a href="https://www.jove.com/files/ftp_upload/62606/62606fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/62606/62606fig02.jpg" /> 
Figure 2: Gait analysis with the CatWalk XT system. (A) Picture of the CatWalk XT apparatus. (B) Examples of the print view showing the labeled paw prints in false color mode and examples of the timing view showing time-based gait diagram of wt na&#239;ve rats and wt rats five weeks after nerve crush injury. (C) Examples of the toe classification showing the toe spread (TS), intermediate toe spread (ITS) and print length (PL) as well as examples of the body axis view showing the body axis (white line) and the movement vector (red line) of wt na&#239;ve rats and wt rats five weeks after nerve crush injury. (D) Data of selected parameters from the &#34;standard&#34; classification comparing wt na&#239;ve rats and wt rats five weeks after nerve crush injury. (E) Data of selected parameters from the &#34;Interactive Footprint Measurements module&#34; comparing wt na&#239;ve rats and wt rats five weeks after nerve crush injury. Data are shown as mean &#177; SEM. Statistical analysis was performed using the unpaired t test of the normally distributed data, unpaired t test with Welch&#39;s correction of normally distributed data with unequal variance and Mann-Whitney U test of the non-normal distributed data. P-value &#60; 0.05 was defined as statistically significant labeled as *p &#60; 0.05, **p &#60; 0.01, ***p &#60; 0.001, ****p &#60; 0.0001. <a href="https://www.jove.com/files/ftp_upload/62606/62606fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/62606/62606fig03.jpg" /> 
Figure 3: Gait analysis with the beam walking task. (A) Picture and schematic drawings of the beam walking task setup. The latency time to cross the beam (B) and the percentage foot slip errors per step of the nerve-injured hindlimb during the beam walking task (C) was analyzed in wt na&#239;ve rats and wt rats five weeks after nerve crush injury. Representative picture for the start time position (D) and the end time position (E) of the beam walking task. Representative image sequence of a full slip error (F) and a half slip error (G) of the beam walking task. Data are shown as mean &#177; SEM. Statistical analysis was performed using the Mann-Whitney U test of the non-normal distributed data. P-value &#60; 0.05 was defined as statistically significant labeled as *p &#60; 0.05, **p &#60; 0.01. <a href="https://www.jove.com/files/ftp_upload/62606/62606fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/62606/62606fig04.jpg" /> 
Figure 4: Gait analysis using the ladder rung walking task. Picture (A) and schematic drawings (B) of the ladder rung walking task setup. The latency time of traversing the ladder rung apparatus (C) and the percentage foot slip errors per step of the nerve-injured hindlimb during the ladder rung walking task (D) was assessed in wt na&#239;ve rats and wt rats five weeks after nerve crush injury. (E) The percentage distribution of the score category per step according to the 7-category scale from Metz et al. for the left and right hindlimb of wt na&#239;ve rats and wt rats five weeks after nerve crush injury. Data are shown as mean &#177; SEM. Statistical analysis was performed using the unpaired t test of the normally distributed data and Mann-Whitney U test of the non-normal distributed data. <a href="https://www.jove.com/files/ftp_upload/62606/62606fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/62606/62606fig05.jpg" /> 
Figure 5: Exemplary representation of each category according to the 7-category scale from Metz et al. during the ladder rung walking task. Representative&#160;image sequence from the right hindlimb of category 0 - total miss, category 1 - deep slip, category 2 - slight slip, category 3 - replacement, category 4 - correction, during the ladder rung walking task. Representative pictures for category 5 - partial placement and category 6 - correct placement. <a href="https://www.jove.com/files/ftp_upload/62606/62606fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

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Multifactorial Assessment of Motor Behavior in Rats after Unilateral Sciatic Nerve Crush Injury

We provide a protocol for the assessment of motor behavior via a behavioral test battery in rats after sciatic nerve crush injury.

The induction of a peripheral nerve injury is a widely used method in neuroscience for the assessment of repair and pain mechanisms among others. In ...

The overall goal of this protocol is to describe the procedures involved in performing irreproducible sciatic nerve crush, and to provide a protocol for the assessment of motor behavior after peripheral trauma. The selection of a powerful and reliable behavioral test battery is essential to cover a wide range of behavioral aspects, and depends on the animal model used and scientific research question. This protocol describes in detail how to perform a sciatic nerve crush injury and provides a behavioral test battery for the assessment of motor deficits in rats, that includes the open field test, the CatWalk gait analysis, the beam walking task, and the ladder rung walking task.Animal experiments were performed in accordance with applicable national and institutional guidelines for care and use of animals. Maintain a sterile environment during the whole surgical procedure. Set up the surgery table with the necessary equipment.Deeply anesthetize the rat in a closed cabinet with isoflurane and shave an extensive area of the right hind limb. Next, position the rat into the anesthesia mask and continue deep anesthesia with isoflurane. Fix the torso and both hind limbs of the rat with tape.Place both hind limbs in a symmetrical and outstretched position and turn each paw flat onto the surgery table. Disinfect the skin of the shaved area with an appropriate antiseptic. Search for the sciatic notch of the ileum.Make a skin incision from the sciatic notch into the direction of the paw with a scalpel. If the hind limbs are fixed and the skin incision is performed correctly, a cavity in the fascial plane between the gluteus maximus muscle and biceps femoris muscle can be seen that resembles a white line. Insert closed super-fine hemostatic forceps into the cavity and spread the forceps.The fascial plane should open up without injuring any muscle tissue. Place the rubber band retractors underneath the muscles to keep the skin incision open. Gently remove any surrounding tissue and blood vessels from the sciatic nerve until the nerve is completely exposed.It is important to not stretch or pull the nerve during the whole procedure. Crush the sciatic nerve with a non-serrated clamp with constant and rapid usable pressure. For this, open the clamp, place the nerve onto the bottom jaw of the clamp, and close the clamp by locking it into the first position for 3 x 10 seconds.After the crush injury, reopen the clamp carefully. the crush site of the sciatic nerve appears translucent. Remove the rubber band retractors.Close the fascial plane incision with a resorbable suture. Close the skin incision with body skin staples. The locomotor activity, as well as the behavioral activity of rats can be analyzed by an open field test.The setup of the open field, which should be located in a dark and quiet environment, consists of the automated video tracking system, EthoVision XT, and an arena with a scratch-resistant, cleanable black surface. Place the arena and the camera into the correct position and set up the EthoVision XT software. Place the rat gently in the middle of the testing arena.During the recording, the experimenter should stay away from the open field set up, in order to avoid distracting the rat. For the data analysis of the open field test, go to the analysis section in the left sidebar and choose Track Visualization"under the Results"tab. Next, export the needed parameters to XL.Within the software, choose a number of variables from different categories for data analysis.A gait analysis by the CatWalk XT system can help to assess many different parameters concerning the footprints, stance and gait of animal models. A glass walkway is illuminated with green light and the light scattered by the footprints of the animals is captured with a high speed video camera, which is located underneath the walkway. The signals can be analyzed with the CatWalk XT software.The experiment has to be performed under dark conditions. Start by setting up the CatWalk XT system. Choose the Experimental settings.Place the camera in position and adjust the focus. Set up the detection settings. Set up the corridor walls of the CatWalk system and make sure the walls remain parallel to the walkway.Define the length of the walkway and calibrate the walkway. Next, snap a background image. A clean and empty walkway is needed for the background image.The rat should cross the walkway without any interruption. According to the defined run criteria, three compliant runs per rat are needed for data analysis. Train animals for at least eight days before you start with the actual experiment.The CatWalk should be performed at least once a week, with 6 to 10 runs to ensure a continuous task performance. For data analysis, only evaluate the compliant runs. Classify paw prints automatically with the CatWalk XT software.Review the paw print labels manually. Correct wrong paw print labels, add labels of non-detected paw prints, and delete any noise and wrong labels. The numerical results displayed in an XL sheet, showing a number of basic parameters.For more detailed information about each footprint, classify the toes of the hind paws. This analysis requires the interactive footprint measurements module. Set the markers for the footprint analysis manually.Analyze every hind paw print in all three compliant runs. Draw a line from the center of the first toe to the center of the fifth toe to measure toe spread. Draw a line from the center of the second toe to the center of the fourth toe to measure intermediate toe spread.Draw a line from the center of the third toe to the heel of the hind paw to measure manual print length. Review the numerical results of the interactive footprint measurements displayed in a separate sheet. Gait deficits can be determined by the beam walking task.The focus of the beam walking task in this specific research topic will be the analysis of motor coordination and not the assessment of motor balance. For the beam walking task, a beam, spacer, table, uniform background, and a camcorder are needed. Use a wooden beam of 90 centimeters in length, 1.7 centimeters in width, and 2 centimeters in height.Train the animals for seven days. Place the rat on the start platform of the beam. The rat should cross the beam three times without any interruption.Even if the rat reaches three compliant runs within the first three runs, a minimum of 6 to 10 runs should be carried out for continuous task performance. Select the video sequences of three compliant runs from the recording. Define the start time point and the end time point of the selected three compliant runs.Here, the start time point is labeled by a black line on the beam, and the placement of the first hind limb behind the black line is defined as the start time point of the run. The placement of the first hind limb on the platform at the end of the beam defines the end time point. Next, calculate the time needed for the rat to cross beam.Score the number of steps and errors from three compliant runs for both hind limbs separately, by using the zoom and slow motion function of the software. Errors include total foot slips and half foot slips. A total foot slip is defined as a foot placement that is followed by deep slip, causing a loss of contact of the affected paw with the beam.A half slip is defined as the paw sliding off the sidewall of the beam without losing complete contact. Calculate the percentage of foot slips in relation to the number of steps to cross the beam. The ladder rung walking task can assess motor function, placement of both front limbs and hind limbs, and inter-limb coordination.A ladder rung apparatus, spacer, table, uniform background, and camcorder are needed for this behavioral test. The horizontal letter rung apparatus consists of metal rungs and clear polycarbonate sidewalls. Train the animals for eight days.Place the rat on the start zone of the ladder rung operators. The rat has to cross the 100 centimeter walkway of the ladder rung apparatus three times without an interruption, in order for it to qualify as a compliant run. Select the video sequences of three compliant runs from the recording.Define the start time point and the end time point of the selected three compliant runs. The placement of the hind limb behind the first black line on the sidewall of the apparatus defines the start time point of the run. The placement of the first front limb behind the second black line on the sidewall of the apparatus defines the end time point of the run.Next, calculate the duration of the run across the walkway. Score the three compliant runs with the 7 category scale from Mets and colleagues by using the slow motion or the frame-by-frame function of the software. Determine the number of steps and the number of errors in accordance with the categories of the scale for each limb separately.The scale distinguishes between the following categories. Total miss. Deep slip.Slight slip.Replacement.Correction. Partial placement. And correct placement.Next, calculate the errors per step. The representative results of the five minute open field test show that the nerve crush injury, five weeks post surgery, has no effect on the locomotor activity. Gait analysis with the CatWalk XT system generates many different parameters.Significant alterations could be detected for the run average speed, the stride length, and the print area of the nerve-injured right hind paw. Nerve-injured wild type rats showed a significantly increased latency time to cross the beam, compared to wild type naive rats five weeks post-injury. As an additional readout of the beam walking task, full slips and half slips of the nerve-injured hind limb were counted and considered as an error for statistical analysis.The percentage of errors per step of the nerve-injured right hind limb was significantly increased in nerve-injured wild type rats, compared to wild type naive rats. Representative data of the ladder rung walking task does not show significant alterations in the latency time to cross the walkway of the ladder rung apparatus, or in the percentage of errors per step of the nerve-injured right hind limb. The analysis of the error percentage per step of the nerve-injured hind limb considered only the score from 0 to 2 of the 7 category scale from Mets and colleagues.After watching this video, you should have a good understanding of how to perform a sciatic nerve crush injury, and how to implement a multi-factorial assessment of motor behavior in rats after unilateral sciatic nerve crush. To achieve consistent, reproducible and comparable results after a sciatic nerve crush injury, a standardized method for inducing the nerve crush is essential, as well as a standardized phenotypically characterization. Proper training for specific behavior test provides the advantages of saving time during the experiment assessment and obtaining better results.

Multifactorial Assessment of Motor Behavior in Rats after Unilateral Sciatic Nerve Crush Injury

Abstract