This study was supported in part by the Japan Society for the Promotion of Science (JSPS) KAKENHI (no. 18H03129, 21K19709, 21H03302, 15K10441) and the Japan Agency for Medical Research and Development (AMED) (no. 15bk0104037h0002).

The present study was approved by the Kyoto University Animal Experimental Committee (Med Kyo 14033) and performed in compliance with National Institute of Health guidelines (Guide for the Care and Use of Laboratory Animals, 8th Edition). 7-week-old male Wistar rats were used for the present study. A schematic representing the sequence of procedures is provided in Supplementary File 1.
1.&#160;Familiarizing rats with treadmill walking
NOTE: Please see the previously published report13 for details regarding the procedure.
<ol>
	<li>Place the rat on a treadmill designed for rodents (see Table of Materials). In the first session, allow the animal to explore the treadmill to become accustomed to the environment. 
	NOTE: This process takes approximately 5 min.</li>
	<li>Gradually increase the belt&#39;s velocity to the desired level (20 cm/s) and walk the rat. Use an electric shock at the end of the treadmill if needed14. 
	NOTE: One walking session lasts approximately 10-20 min.</li>
	<li>Repeat this process every other day for 1 week or more frequently if needed15,16,17. 
	NOTE: Start the familiarization period 1 week prior to step 2.</li>
	<li>Keep the rats in groups in cages (2-3 rats in each cage) with a 12 h light-dark cycle. Provide food and water ad libitum.</li>
</ol>
2. Application of hindlimb unloading to the rats and setting up of joint markers
NOTE: Elevate the hindlimbs of the rat using thread and adhesive tape attached to the tail as described in previous reports18,19,20. Make sure the thread and tape are attached at the base of the tail to prevent slippage of the tail skin. Monitor the animals thoroughly and adjust the unloading height or tightness of the tape if needed.
<ol>
	<li>Under 2-5% isoflurane inhalation with an anesthetic mask, wrap the first half of a 30 cm long strip of adhesive tape around the proximal portion of the rat&#39;s tail.</li>
	<li>Fold a 1 m long cotton thread (cotton kitchen twine, approximately 1 mm diameter) into half. Make a loop by tying a knot at the folded 50 cm midpoint. The knot must be approximately 5 cm from the tip to leave a 10 cm circumference loop.</li>
	<li>Allow the remaining 15 cm of the adhesive tape to pass once through the thread loop to secure the tape. Wrap the remaining tape around the distal portion of the tail.</li>
	<li>Secure the other tip of the thread on the overhead platform of the cage. Keep the animals in a cage that is high enough to elevate their hindlimbs by their tails. Other than the unloading, provide the same environment as those for the Ctrl group, such as food, water, and floor bedding.</li>
	<li>Set up the joint markers and software (see Table of Materials) following the steps below. 
	NOTE: For details regarding this step, please see Wang et al.13.
	<ol>
		<li>Under 2-5% isoflurane inhalation, attach colored semispherical markers (3 mm diameter) to the shaved skin corresponding to bony landmarks. Keep the isoflurane level as low as possible to prevent very deep anesthesia.</li>
		<li>Ensure that the landmarks are the anterior superior iliac spine (ASIS), trochanter major (hip joint), knee joint (knee), lateral malleolus (ankle), and fifth metatarsophalangeal joint (MTP)21. 
		NOTE: Paint the tip of the toe if the angle of the toe is needed. Use an oil-based paint marker (see Table of Materials). Liquid glue is preferable for adhesive since the liquid form dries faster.</li>
	</ol>
	</li>
</ol>
3. Marker tracking using captured videos
<ol>
	<li>Open the MotionRecorder app (see Table of Materials) and turn on the treadmill. Place the rat on the treadmill belt. 
	NOTE: The four cameras for video capture (see Table of Materials) are laid out along the long edges of the treadmill: two cameras on each edge, approximately 50 cm x 50 cm apart, facing the center of the treadmill belt area.</li>
	<li>Increase the belt speed up to 20 cm/s. As the rat begins walking normally at the desired speed, click on the Record icon to start the video capture. Once enough steps (5 consecutive steps, preferably 10 steps) are obtained, stop the capture by clicking on the Record icon again. 
	NOTE: Capture data on multiple animals in one experiment. Try up to five times for each rat. If a rat does not walk, capture a different one and try the first one later. The capturing rate of the camera was 120 frames/s.</li>
	<li>Open the 3DCalculator app (see Table of Materials) and the video file to be analyzed.</li>
	<li>Crop the video by adjusting the horizontal slider bar on the top to contain enough numbers of consecutive steps. Captured image changes by dragging the yellow slide bar&#39;s end tip icon(s).</li>
	<li>To capture the markers, select the marker legends by clicking on the marker legends on the stick picture model, dragging them to the corresponding marker on the captured video, and releasing the button. This process allocates the color of the marker to the marker legend in the stick picture. Repeat this process for every marker to be tracked.</li>
	<li>Click on the Automatic trace icon. If the system does not accurately track markers or the tracking process halts due to marker loss, switch to manual mode. 
	NOTE: This automatic process does not halt unless the markers are missed. If halts happen more often than every few frames, consider repositioning the lost markers.</li>
	<li>If manual mode is needed, click the Manual icon to switch. Click the missing marker legend on the stick picture and the corresponding marker on the video. The video proceeds with one frame for each click in the manual mode. 
	&#8203;NOTE: Utilize freely available apps that enable auto click to prevent fatigue of those who track (digitize) the markers (see Table of Materials).</li>
</ol>
4. Computation of desired parameters
<ol>
	<li>Open the KineAnalyzer app (see Table of Materials) and load the file.</li>
	<li>Go to the View &#62; Edit Marker Master menu.It opens the &#34;Marker master edit&#34; window. 
	NOTE: Captured markers have simple numbers until they are labeled.</li>
	<li>Click on the desired label (landmark) on the marker tab, then click on the desired color. This process designates each marker to a specific landmark.</li>
	<li>Go to the link tab. Create lines by clicking on two markers consecutively. This process creates lines that correspond to each limb using labeled markers.</li>
	<li>Assign colors to the created lines by selecting the desired color from the Color column.</li>
	<li>Define angles by assigning reference/moving lines and directions of the angles. Go to the angle tab. After naming the angle, assign Vector A (reference line) and Vector B (moving line) by clicking on the markers corresponding to each landmark. Then, define the direction of the angle with a value in the operate section in the same tab. 
	NOTE: For the present study, the parameters mainly focused on were at the middle of the stance phase (midstance): KSt (knee angle), ASt (ankle angle), MHD (metatarso hip distance: equivalent to the height of the hip, see the next section). Knee angle and ankle angle were defined as the angle between the femur and tibia and the tibia and fifth metatarsal bone, respectively. A 0&#176; angle means that the joint was fully flexed.</li>
	<li>On the distance tab, define the distance parameter (MHD). Select two corresponding markers in the Distance Setting section. Joint trajectories as a function of normalized step cycle will also be available. 
	NOTE: Defining angles/parameters needs to be performed only one time. The settings of the parameters will be available for later evaluations once this defining process is completed.</li>
</ol>

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The authors declare that there is no conflict of interest.

Alteration of environments leads to fluctuating functional aspects and musculoskeletal components of locomotor systems26,27. Aberrations in contractile structures or environments may affect functional abilities, persisting even after resolving mechanical/environmental distortions19. Objective motion analysis helps to measure those functional abilities quantitatively. As shown above, video analysis is a powerful methodology for acquiring su...

Lack of physical activity or disuse leads to the deterioration of locomotor effectors, such as muscle atrophy and bone loss1 and whole-body deconditioning2. Moreover, it has recently been noticed that inactivity affects not only structural aspects of musculoskeletal components but also qualitative aspects of the movement. For example, the limb positions of rats exposed to a simulated microgravity environment were different from those of intact animals even 1 month after the intervention ended3,4. Nevertheless, little has been reported on motion deficits caused by inactivity. Also, comprehensive motion characteristics of the deteriorations have not been fully determined.
The current protocol demonstrates and discusses the application of kinematic evaluation to visualize motion alterations by referring to gait motion deficits evoked through disuse in rats subjected to hindlimb unloading.
It has been shown that hyperextensions of limbs in walking after a simulated microgravity environment are observed both in humans5 and animals4,6,7,8. Therefore, for universality, we focused on general parameters in this study: angles of the knee and ankle joints and vertical distance between the metatarsophalangeal joint and hip (roughly equivalent to the height of the hip) at the middle point of the stance phase (midstance). Further, potential applications of video kinematic evaluation are suggested in the discussion.
A series of kinematic analyses may be an effective measure to assess functional aspects of neural control. However, although motion analyses have been developed from footprint observation or simple measuring on captured video9,10 to multiple camera systems11,12, universal methods and parameters are yet to be established. The method in this study is intended to provide this joint motion analysis with comprehensive parameters.
In the previous work13, we tried illustrating gait alterations in nerve lesion model rats using comprehensive video analysis. However, in general, the potential outcomes of motion analyses are often restricted to predetermined variables provided in the analysis frameworks. For this reason, the present study further detailed how to incorporate user-defined parameters that are broadly applicable. Kinematic evaluations using video analyses may be of further use if proper parameters are implemented.

<table><tbody><tr><td>Adhesive Tape</td><td>NICHIBAN CO.,LTD.</td><td>SEHA25F</td><td>Adhesive tape to secure thread on tails of rats for hindlimb unloading</td></tr><tr><td>Anesthetic Apparatus for Small Animals</td><td>SHINANO MFG CO.,LTD.</td><td>SN-487-0T</td><td></td></tr><tr><td>Auto clicker</td><td>N.A.</td><td>N.A.</td><td>free software available to download to PC (https://www.google.com/search?client=firefox-b-1-d&amp;amp;q=auto+clicker)</td></tr><tr><td>CCD Camera</td><td>Teledyne FLIR LLC</td><td>GRAS-03K2C-C</td><td>CCD (Charge-Coupled Device) cameras for video capture</td></tr><tr><td>Cotton Thread</td><td>N.A.</td><td>N.A.</td><td>Thread to hang tails of rats from the ceiling of cage</td></tr><tr><td>ISOFLURANE Inhalation Solution</td><td>Pfizer Japan Inc.</td><td>(01)14987114133400</td><td></td></tr><tr><td>Joint marker</td><td>TOKYO MARUI Co., Ltd</td><td>0.12g BB</td><td>6 mm airsoft pellets that were used as semispherical markers with modification</td></tr><tr><td>Kine Analyzer</td><td>KISSEI COMTEC CO.,LTD.</td><td>N.A.</td><td>Software for analysis</td></tr><tr><td>Konishi Aron Alpha</td><td>TOAGOSEI CO.,LTD.</td><td>#31204</td><td>Super glue to attach spherical markers on randmarks of rats</td></tr><tr><td>Motion Recorder</td><td>KISSEI COMTEC CO.,LTD.</td><td>N.A.</td><td>Software for video recording</td></tr><tr><td>Paint Marker</td><td>MITSUBISHI PENCIL CO., LTD</td><td>PX-21.13</td><td>Oil based paint marker to mark toes of animals</td></tr><tr><td>Three-dimensional motion capture apparatus (KinemaTracer for small animals)</td><td>KISSEI COMTEC CO.,LTD.</td><td>N.A.</td><td>3D motion analysis system that consists of four cameras (https://www.kicnet.co.jp/solutions/biosignal/animals/kinematracer-for-animal/ or https://micekc.com/en/)</td></tr><tr><td>Three-dimensional(3D) Calculator</td><td>KISSEI COMTEC CO.,LTD.</td><td>N.A.</td><td>Software fo marker tracking</td></tr><tr><td>Treadmill</td><td>MUROMACHI KIKAI CO.,LTD</td><td>MK-685</td><td>Treadmill equipped with transparent housing, electrical shocker, and speed control unit</td></tr><tr><td>Wistar Rats (male, 7-week old)</td><td>N.A.</td><td>N.A.</td><td>Commercially available at experimental animal sources</td></tr></tbody></table>

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.

12 animals were randomly assigned to one of two groups: the unloading group (UL, n = 6) or the control group (Ctrl, n = 6). For the UL group, the hindlimbs of the animals were unloaded by the tail for 2 weeks (UL period), whereas the Ctrl group animals were left free. 2 weeks after unloading, the UL group showed a distinct gait pattern compared with the Ctrl group. Figure 1 shows normalized joint trajectories of representative subjects. During the stance phase, the UL group exhibited further...

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Comprehensive Understanding of Inactivity-Induced Gait Alteration in Rodents

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 ...

comprehensive-understanding-inactivity-induced-gait-alteration

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2.3K Views.  Kyoto University. The present protocol describes three-dimensional motion tracking/evaluation to depict gait motion alteration of rats after exposure to a simulated disuse environment. 

Video: Comprehensive Understanding of Inactivity-Induced Gait Alteration in Rodents

Getting to Compliance in Forced Exercise in Rodents: A Critical Standard to Evaluate Exercise Impact in Aging-related Disorders and Disease

There is a major increase in the awareness of the positive impact of exercise on improving several disease states with neurobiological basis; these include improving cognitive function and physical performance. As a result, there is an increase in the number of animal studies employing exercise. It is argued that one intrinsic value of forced exercise is that the investigator has control over the factors that can influence the impact of exercise on behavioral outcomes, notably exercise frequency, duration, and intensity of the exercise regimen. However, compliance in forced exercise regimens may be an issue, particularly if potential confounds of employing foot-shock are to be avoided. It is also important to consider that since most cognitive and locomotor impairments strike in the aged individual, determining impact of exercise on these impairments should consider using aged rodents with a highest possible level of compliance to ensure minimal need for test subjects. Here, the pertinent steps and considerations necessary to achieve nearly 100% compliance to treadmill exercise in an aged rodent model will be presented and discussed. Notwithstanding the particular exercise regimen being employed by the investigator, our protocol should be of use to investigators that are particularly interested in the potential impact of forced exercise on aging-related impairments, including aging-related Parkinsonism and Parkinson&#8217;s disease.

Exercise may alleviate behavioral impairments associated with neurodegenerative diseases. Studies of the mechanisms underlying exercise-mediated effects have increased in disease models, but the neurobiological background accompanying these diseases, specifically aging, is likely not considered. Here, we illustrate measures to increase the likelihood of a successful exercise paradigm in aged rats.

There is a major increase in the awareness of the positive impact of exercise on improving several disease states with neurobiological basis; these ...

Behavior

3D Kinematic Gait Analysis for Preclinical Studies in Rodents

The utility of three-dimensional (3D) kinematic motion analysis systems is limited in rodents. Part of the reason for this inadequacy is the use of complex algorithms and mathematical modeling that accompany 3D data collection and analysis procedures. This work provides a simple, user-friendly, step-by-step detailed methodology for 3D kinematic gait analysis during treadmill locomotion in healthy and neurotraumatic rats using a six-camera motion capture system. Also provided are details on 1) calibration of the system in an experimental set-up customized for quadrupedal locomotion, 2) data collection for treadmill locomotion in adult rats using markers positioned on all four limbs, 3) options available for video tracking and processing, and 4) basic 3D kinematic data generation and visualization and quantification of data using the built-in data collection software. Finally, it is suggested that the utility of this motion capture system be expanded to studying a variety of motor behaviors before and after neurotrauma.

Presented here is a protocol to collect and analyze three-dimensional kinematics of quadrupedal locomotion in rodents for preclinical studies.

The utility of three-dimensional (3D) kinematic motion analysis systems is limited in rodents. Part of the reason for this inadequacy is the use of ...

Gait Analysis of Age-dependent Motor Impairments in Mice with Neurodegeneration

Motor behavior tests are commonly used to determine the functional relevance of a rodent model and to test newly developed treatments in these animals. Specifically, gait analysis allows recapturing disease relevant phenotypes that are observed in human patients, especially in neurodegenerative diseases that affect motor abilities such as Parkinson&#39;s disease (PD), Alzheimer&#39;s disease (AD), amyotrophic lateral sclerosis (ALS), and others. In early studies along this line, the measurement of gait parameters was laborious and depended on factors that were hard to control (e.g., running speed, continuous running). The development of ventral plane imaging (VPI) systems made it feasible to perform gait analysis at a large scale, making this method a useful tool for the assessment of motor behavior in rodents. Here, we present an in-depth protocol of how to use kinematic gait analysis to examine the age-dependent progression of motor deficits in mouse models of neurodegeneration; mouse lines with decreased levels of endophilin, in which neurodegenerative damage progressively increases with age, are used as an example.

In this study, we demonstrate the use of kinematic gait analysis based on ventral plane imaging to monitor the subtle changes in motor coordination as well as the progression of neurodegeneration with advancing age in mouse models (e.g., endophilin mutant mouse lines).

Motor behavior tests are commonly used to determine the functional relevance of a rodent model and to test newly developed treatments in these animals. ...

Developmental Biology

Low-Cost Gait Analysis for Behavioral Phenotyping of Mouse Models of Neuromuscular Disease

Measurement of animal locomotion is a common behavioral tool used to describe the phenotype of a given disease, injury, or drug model. The low-cost method of gait analysis demonstrated here is a simple but effective measure of gait abnormalities in murine models. Footprints are analyzed by painting a mouse&#8217;s feet with non-toxic washable paint and allowing the subject to walk through a tunnel on a sheet of paper. The design of the testing tunnel takes advantage of natural mouse behavior and their affinity for small dark places. The stride length, stride width, and toe spread of each mouse is easily measured using a ruler and a pencil. This is a well-established and reliable method, and it generates several metrics that are analogous to digital systems. This approach is sensitive enough to detect changes in stride early in phenotype presentation, and due to its non-invasive approach, it allows for testing of groups across life-span or phenotypic presentation.

Footprint analysis is a low-cost alternative to digitized gait analysis programs for researchers quantifying movement abnormalities in mice. Because of its speed, simplicity, and longitudinal potential, it is ideal for behavioral phenotyping of mouse models.

Measurement of animal locomotion is a common behavioral tool used to describe the phenotype of a given disease, injury, or drug model. The low-cost method ...

Validating a Murine Model of Angelman Syndrome Using Behavioral Tests

Behavioral Characterization of an Angelman Syndrome Mouse Model

This manuscript describes a battery of behavioral tests available to characterize Angelman syndrome (AS)-like phenotypes in an established murine model of AS. We use the rotarod learning paradigm, detailed gait analysis, and nest building test to detect and characterize animal motor impairments. We test animal emotionality in the open field and elevated plus maze tests, as well as the affect in the tail suspension test. When AS mice are tested in the open field test, the results should be interpreted with care, since motor dysfunctions influence mouse behavior in the maze and alter activity scores.
The reproducibility and effectiveness of the presented behavioral tests has already been validated in several independent Uba3a mouse lines with different knockout variants, establishing this set of tests as an excellent validation tool in AS research. Models with the relevant construct and face validity will warrant further investigations to elucidate the pathophysiology of the disease and grant the development of causal treatments.

Author Spotlight: A Battery of Highly Reproducible Behavioral Tests to Validate an Angelman Syndrome Murine Model 

This manuscript presents a set of highly reproducible behavioral tests to validate an Angelman syndrome mouse model.

This manuscript describes a battery of behavioral tests available to characterize Angelman syndrome (AS)-like phenotypes in an established murine model of ...

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 ...

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.

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 ...

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 ...

Applying the RatWalker System for Gait Analysis in a Genetic Rat Model of Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta. Gait abnormalities, including decreased arm swing, slower walking speed, and shorter steps are common in PD patients and appear early in the course of disease. Thus, the quantification of motor patterns in animal models of PD will be important for phenotypic characterization during disease course and upon therapeutic treatment. Most cases of PD are idiopathic; however, the identification of hereditary forms of PD uncovered gene mutations and variants, such as loss-of-function mutations in Pink1 and Parkin, two proteins involved in mitochondrial quality control that could be harnessed to create animal models. While mice are resistant to neurodegeneration upon loss of Pink1 and Parkin (single and combined deletion), in rats, Pink1 but not Parkin deficiency leads to nigral DA neuron loss and motor impairment. Here, we report the utility of FTIR imaging to uncover gait changes in freely walking young (2 months of age) male rats with combined loss of Pink1 and Parkin prior to the development of gross visually apparent motor abnormality as these rats age (observed at 4-6 months), characterized by hindlimb dragging as previously reported in Pink1 knockout (KO) rats.

Here we describe the RatWalker system, built by redesigning the MouseWalker apparatus to accommodate for the increased size and weight of rats. This system uses frustrated total internal reflection (FTIR), high-speed video capture, and open-access analysis software to track and quantify gait parameters.

Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by the loss of dopaminergic (DA) neurons in the substantia nigra pars ...

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.

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 ...