As science progresses, scientists are pushing the limits of gait analysis by trying to find useful gait-related endpoints in extremely young, extremely fat, or extremely gait-impaired rodents in their studies. At Noldus, we strive to continuously improve our systems to facilitate these researchers.
New in CatWalk XT 10.6 is the option of a colorized view in footprint classification. This way you can easily see which print belongs to which paw.
Other recent new features (CatWalk XT 10.5)
Adjustable light intensities
The CatWalk XT Control Unit provides power to the red LED lights in the CatWalk XT ceiling, green LED lights along the walkway (which are reflected by the plantar surface of the rodent’s paw), and the camera. In CatWalk XT 10.5, you can connect this unit to your computer with a standard USB cable and control both the red and green LED light intensity from within the software.
Now that you are able to choose the optimal lighting conditions, depending on the intrinsic properties of the animal (weight, size, impairment) and environmental light conditions, you can reach optimal detection of each paw placement. This greatly improved the sensitivity and flexibility of the system.
Zooming into the recorded run video
In CatWalk XT 10.5, we have introduced a much requested feature. It is now possible to zoom, up to four times, into the recorded run video in order to review or (re)classify the green walkway contacts (footprints) made by the animal.
Combined paw print image
In the CatWalk XT software, the run video can be displayed frame by frame. However, then you can only see part of the complete paw print of the entire stance. Now we have incorporated a dynamic representation of the combined image of each footfall alongside the run video in four windows - one for each paw. Seeing this image is of great value while reviewing a run.
Automatic detection of classification errors
Footprint classification might be difficult in some animals, such as very heavy or severely impaired animals, even by hand. In 10.5, the software now automatically detects classification conflicts. You can select them from a dropdown box, upon which the video automatically jumps to the corresponding time point. You can use the zoom function to look at the print in detail. Then you can (re)classify the print as you see fit.
View parameter charts
CatWalk XT 10 contains a new analysis possibility- View parameter charts. This possibility will provide you with graphs for every parameter you are interested in and have selected in your “parameter profile”. This way it will be very easy to see how gait is changing between your experimental groups, over time. The generated graphs can be exported to either programs such as PowerPoint or as a PDF report.
Additional parameters for the IFM module
The Sciatic Functional index was introduced last year, and is commonly used as a tool for the evaluation of the functional recovery of sciatic nerve injury. Now we have added two extra indices to this module, allowing you to calculate:
- The Tibial Functional Index (TFI), used in the study of tibial nerve injury recovery
- The Peroneal Functional Index (PFI), used in the study of peroneal nerve (also called fibular nerve) injury recovery
The tibial and the peroneal nerve are two branches of the sciatic nerve. Just like the Sciatic Functional Index, these new indices are also calculated based on toe spread, intermediate toe spread, and print length.
- Adjust intensity threshold after recording a run
Every paw print will be expressed in a green signal. You can manually change the amount of green signal that is going to be filtered out of each run. Adjusting the intensity threshold allows you, for instance, to filter out noise or overexposed paws. It can also help you to include filtered out parts of a print again.
- Combining steps
Sometimes, in severely affected animals, a single footfall may be broken up into two or more stances. CatWalk XT will incorrectly calculate its parameters with these additional footprints. Cases like these can easily be repaired by combining the two pieces of the fragmented print back into one footfall.
The new CatWalk XT control unit will provide power to the red LED lights in the illuminated ceiling. It will also provide power to the green LED rail alongside the walkway and it will provide power to the camera. Each of these circuits has a unique cable with a high quality connector.
- Redesigned corridor to facilitate throughput
The redesign consists of a wider opening on the left side of the corridor, stiffer corridor walls, and an extra diffusion plate between the red LED’s of the top-unit. This extra diffusion plate ensures that the red LED light from the illuminated ceiling is more evenly distributed over the entire width and length of the walkway. Most importantly is a spring operated lifting mechanism that lifts the entire walkway upwards. This can be done with only two fingers, allowing easy access to the glass plate for cleaning and/or removal of animals.
Your time is valuable. You need to accomplish your research goals quickly and efficiently and yet at the same time, you want to acquire objective and accurate data. When investigating gait disturbances in rodents, CatWalk XT is the system that does it all. And with the goal box, research becomes even more efficient.
The goal box is a new addition to the CatWalk XT system. It is mounted at one end of the runway and consists of a black shelter with room for a home cage underneath, which the animal can access through a hole. Both motivate your mouse or rat to cross the runway in a consistent manner. This reduces the time it takes to train your animals and improves the quality of the data you acquire during the experiments. With a goal box at the end of the runway including a home cage underneath, the animal is less likely to stop along the way or turn around, motivated by the desire to go to the safety of familiar surroundings. In other words, more runs will be compliant with your run criteria.