Kahnau, P. | bioRxiv Science

bioRxiv2020

O mouse, where art thou? The Mouse Position Surveillance System (MoPSS) - an RFID based tracking system

Existing methods for analysis of home cage based preference tests are either time consuming, not suitable for group management, expensive and/or based on proprietary equipment that is not freely available. For this reason, we developed an automated system for group housed mice based on radio frequency identification: the Mouse Position Surveillance System (MoPSS). The system uses an Arduino microcontroller with compatible components, it is affordable and easy to rebuild for every laboratory. The MoPSS was validated using female C57BL/6J mice and manual video comparison. It proved to be accurate even for fast moving mice (up to 100 % accuracy after logical reconstruction), and is already implemented in several studies in our laboratory. Here, we provide the complete construction description as well as the validation data and the results of an example experiment. This tracking system will allow group-based preference testing with individually identified mice to be carried out in a convenient manner, creating the foundation for better housing conditions from the animals perspective.

animal behavior and cognition↗

bioRxiv2020

Alternate without alternative: Neither preference nor simple learning behaviour shown by C57BL/6J mice in the T-maze

In rodents, the T-maze test is commonly used to investigate spontaneous alternating behaviour but it can also be used to investigate memory, stimuli discrimination or preference between goods. However, especially regarding T-maze preference tests there is no recommended protocol and researchers frequently report reproduction difficulties of this test using mice. Here, we aimed to develop an efficient protocol with female C57BL/6J mice, conducting two preference tests with different design: In a first test, on two consecutive days with five trials, thirteen mice had to choose between two fluids. In a second preference test, on five consecutive days with two (week 1) or three (week 2) trials, twelve mice had to choose between one arm containing bedding mixed with millet and one containing only bedding. This test design resembled a simple learning test (learn where to find the rewarded and the unrewarded arm on the basis of spatial, olfactory and visual cues). In both experiments, mice took only a few seconds per trial to run the maze and make their choice. However, in both experiments mice failed to show any preference for one of the arms. Instead, they alternated choices. We therefore believe the T-maze test to be rather unsuitable to test preference or learning behaviour with C57BL/6J mice.

animal behavior and cognition↗