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ID: 93 (Conflict of Interest: K)

Erstellung einer Baseline physiologischer Gangparameter für Balb/c und C57Bl/6 Mäuse – eine Ganganalyse Studie mittels Catwalk XT 10

T.Fritz1, B.Braun2, J.Meeß1, T. Histing3, M.Klein1, T.Pohlemann1, M. D.Menger1, M. W.Laschke1
1Universitätsklinikum des Saarlandes, Homburg
2Universitätsklinikum Homburg, Homburg
3Universitätsklinikum , Homburg

Einleitung

Studies using gait analysis in a clinical context, are already well established in current research. In animal research, in vivo gait analysis has also evolved in the last few years and is growing more important. Most published studies use the Catwalk gait analysis system, to assess neurological and pharmacological differences in rodent models. Using the Catwalk XT 10 (Noldus, Netherlands) a multitude of gait parameters can be assessed in real time.

The goal of this study was to analyze physiological walking patterns and parameters of different mouse stems, using female Balb/c and C57BL/6 mice with the same bodyweight (20g).

This study showed differences between both mouse, which results in significant differences between both mouse stems. This study shows that gait analysis in mice may be a helpful tool in the assessment of gait analysis, but also differences of mouse stems must be considered carefully in planning and comparing studies.

Material und Methoden

Animals

We used female Balb/c and C57BL/6 mice with an average of 4 months and a body weight of 20g ± 2 g.

Gait analysis

Gait analysis in mice was performed using an automated computer assisted method the Catwalk XT 10 as described in previous studies (Hetze et al. 2012, Hamers et al. 2001). The Catwalk consists of an elevated 1.3 m long glass plate which is illuminated by a green fluorescent light. The camera records the reflecting light when a mouse crosses the walkway and the paws have contact with the glass plate. Each mouse was placed individually and free to walk in the CatWalk walkway, without conditioning or any stimulus. We acquired 5 complient runs, which had a maximum speed variation of 60%. All other Runs were excluded. The parameters were assessed on day 0 (for training) and 1. All data was recorded and analyzed by CatWalk XT 10. We analyzed both front and hind paws.

Table 1

Data analysis

After testing the data for normal distribution and equal variance, differences between the two species were analyzed by the unpaired Student’s t-test (SigmaPlot 13.0; Systat Software Inc., San Jose, CA, USA). All values are expressed as means ± SEM. Statistical significance was accepted for a value of p<0,05.

Ergebnisse

Run Duration (s), Step Cycle (s), : There were no significant differences between the mouse stems Balb/c and C57BL/6.

Duty Cycle (%): There were significant differences between Balb/c and C57BL/6 mice, for both right front and right hind paws.

Mean Intensity of the 15 Most Intense Pixels (%), Max Contact Area (cm2), : The Mean Intensity of the 15 Most Intense Pixels showed significant higher findings in  C57BL/6 compared to Balb/c mice at front and hind paws.

Print Area (cm²): There was a significant higher Print Area of all paws in the C57Bl/6 compared to Balb/c mice.

Support (%): The Support showed that both mice stems walk significantly in a diagonal paw and three paw walking pattern than any other walking pattern. Yet the significant most used pattern was diagonal.

Schlussfolgerung

The CatWalk is an established and useful tool to analyze walking parameters in rodent studies. When comparing walking parameters of the mouse stems C57BL/6 and Balb/c physiological differences of the walking patterns were found between both mouse stems, which have to be considered when planning a study. There is still not much knowledge about physiological walking patterns and parameters of different mice stems. We think these differences have to be assessed and may be helpful to create a baseline for future studies.

Parameter

Description

Run Duration (s)

Time between start of a single run to cross the walkway

Step Cycle (s)

Time between two consecutive paw placements (Stance Swing Duration)

Duty Cycle (%)

Ratio between the Stance Duration and the Step Cycle Duration

Max Contact Area (cm²)

The paw area contacted at the moment of maximal paw-floor contact

Print Area (cm²)

Surface area of the complete print.

Mean Intensity of the 15 Most Intense Pixels (%)

The mean Intensity of the 15 pixels of a paw with the highest intensity

Support (%)

The relative duration of simultaneous contact with the glass plate of all combinations of paws

 

 

Table 1: Description of assessed parameters in this study. (Catwalk XT 10.6 Reference Manual, Noldus, Wageningen, The Netherlands)