Factors that Influence Experimental Outcomes and How to Overcome Them

Experimental outcomes can be influenced by a variety of factors, some of which can be controlled for. Minimizing confounding factors is crucial to gathering reliable and repeatable results.

One of the biggest issues in animal research today is the replicability of results. Too often animal study outcomes can not be repeated. This is not hard to believe given that the use of animals themselves provides inherent variability, even when all other factors are controlled for. Differences in the strain of animals used, as well as the age of the animals, time of day that experimental tests are administered, and how long the animals were handled prior to experimental testing are just some of the factors that can impact experimental outcomes.

While it is impossible to eliminate all external factors, animal-experimenter interactions can have a huge impact on results and should, therefore, try to be minimized as much as possible.

How can you mitigate animal-experimenter interactions?

At AMUZA, we offer a variety of automated behavioral tests that were designed specifically to improve the reliability and repeatability of behavioral assays.

For example, our Touch Panel operant training system is an automated operant chamber that utilizes photo beam sensors in the touch panel itself to improve the accuracy of responses from small rodents. The Touch Panel also includes software that enables users to design and run their own tasks with video tracking capabilities for automated data collection.

Even our standard mazes come with video tracking and automated data collection and analysis.

Furthermore, one of our other products, the Self Head-Restraining Platform, was designed to completely automate the head-fixation process in mice in order to streamline head-fixed behavioral assays.

In fact, the platform, originally developed by Dr. Andrea Benucci at RIKEN brain institute, was designed specifically to help overcome the reproducibility crisis.

Not only do our tools free up experimenter time and labor to focus on the actual science, they help remove unwanted experimenter bias by standardizing the experimental testing arena.

Even with automated behavioral tasks, however, it is still possible to introduce experimenter bias. This is why we also recommend that you perform rodent behavioral tests at roughly the same time each day, as well as handle experimental animals equally. Ideally, the same experimenter should be handling the animals each day. If this is not realistic, different experimenters should be counterbalanced across days, or across testing groups.

Also, if you plan to use different strains of mice or rats for your experiments, make sure to run behavioral tests across these different strains to account for any strain-specific differences.

Additionally, with our automated rodent behavior systems, we recommend that the motivation of the experimental animals to perform the task is consistent. If animals are food or water-deprived, weights should be taken daily initially and then weekly thereafter to ensure that test subjects are maintained at similar percentages of their free-feeding body weight.

Cleaning the testing chambers between use

All of our behavioral tests are made out of acrylic that is easy to clean as well as removable floors. Testing arenas should always be cleaned between experimental sessions to make sure the scent of the previous animal will not influence behavioral results.