Automated Tube Test

The tube test is a well-known testing paradigm designed to measure social hierarchies, and thus is relevant when investigating social dominance in mice (Lindzey et al., 1961). This is useful in many translational neuroscience studies, including disease models of autism and fragile X syndrome. The basic setup is a tube that is entered on either end by one mouse. Due to the width of the tube, the mice cannot pass each other, so in their struggle to assert the social hierarchy, one will back up (lower status) while the other pushes on (higher status). 

The Automated Tube Test fully automates a validated test to determine social hierarchies in mice. 

Tube testing principle

Traditionally, the tube test is a straight-forward, manual test in which one mouse “wins” and the other “loses”. The downside of performing this test manually is that it requires a large amount of human intervention, including guiding or even pushing the animals into the tube. This introduces artifacts into the data, and it is possible that the animals may not meet in the center of the tube, possibly creating an unfair match. 

The standard manual tube test makes it relatively easy to score which animal wins each bout, but no other data can be gathered. More insight into the social hierarchies can be gained from this test when you measure additional parameters such as duration of match, latency to enter the tube, and more. This additional data is a major benefit of automating the tube test; another benefit is the limited human intervention this brings along. 

The Automated Tube Test

Introducing the Automated Tube Test, a novel apparatus that fully automates validated tube test procedures. This offers several advantages:

  • Animals experience less human intervention
  • No need to force the mouse into the tube
  • In addition to ‘winner’ and ‘loser’, there is an abundance of relevant parameters (see below)
  • Data is reproducible, reliable, and objective
  • Data is more accurate because the starting point is always in the center of the tube (see below) 
  • Animals cannot injure each other
  • Arrives ready-to-go and easy-to-use; no additional data acquisition components are required
  • Provides guidance in setting up experiments and analyzing data.
ATT open chamber
The two boxes on either side of the Automated Tube Test apparatus open on top for easy placement and removal of the mice. 
ATT fully open
The whole apparatus can be opened up for easy cleaning. 

Validated procedure 

The Tube Test is a well-validated test, with a straight-forward procedure. Social dominance relationships and social hierarchies are typically investigated by the following sequence of procedures:

  1. Training sessions: mice are made familiar with the tube. Watch the video!
  2. Match sessions: paired mice are placed in the tube, each in their own start box. The mice walk to each other through the tube and compete by forcing the other back into its start box. Watch the video!
  3. The number of winning matches is counted for each mouse individually.
  4. Social hierarchy within the experimental group is determined by the number of winning matches per mouse.

Please find references to publications in which the Tube Test has been executed here.

Application examples

The testing of hierarchies in mice is relevant in several types of studies. For example, it can be useful to establish the hierarchies in a group of genetically identical mice and compare these results with other social tests carried out in the same group, to add valuable information about the social phenotype of the strain. This experimental set-up would include an all-versus-all design in which each animal in a group is matched against each other animal to establish a complete hierarchy of that group.

It is also useful as a test parameter to see if social hierarchies within a certain strain or model differs from social hierarchies of the wild type. Then the experimental design would involve matching the mutants against the wild type control group. 

Software-hardware combination

The Automated Tube Test automates all steps in the test procedure. The hardware (tube, two start boxes, transparent doors, air valves, and (IR) LED sensors) allows mice to comfortably pass through the tube, without passing one another. The software provides control of the hardware components, continuous collection of the location of both mice, and detailed data analysis. Check the technical specifications. 

Smart design of apparatus

Many social dominance tests are prone to aggressive interactions between competitors, potentially leading to injuries. The dimensions of the Automated Tube Test limit aggressive behaviors during testing and do not allow competitors to injure one another. In manual versions of the tube test, animals are ‘pushed’ into the tube, which may cause problems and inaccuracies in the data or even exclusion of the animal from the test. The Automated Tube Test has start boxes, so the mice are free to enter the tube themselves. It does not matter if they do not enter simultaneously, because the center door in the tube remains closed until both mice reach that point. This way, the match always has the same starting point, something that is very difficult to accomplish with manual testing. 

Abundance of parameters

Measurement parameters are abundant and you can choose which ones to use. The non-exhaustive list of parameters and statistics that are produced during a match or training includes:

  • Date and start time of a match or training.
  • Time elapsed until the mice are first detected in the tube.
  • Time elapsed until the central door opened and the match started.
  • Duration needed for the winning mouse to push the other mouse back into its start box.
  • Identity of the winning mouse for each match.
  • Activation or non-activation of the air valves to release a puff of pressurized air (to goad the mice).
  • Whether the match was a coerced (with air) or non-coerced match.

Read more...

Guidance in experiment set-up and data analysis

The user-friendly Automated Tube Test software provides an easy and efficient platform to set-up experiments and data analysis protocols. Data can be easily exported to your favorite statistical analysis software package. 

Practical apparatus

The complete tube can be opened in between tests in order to conveniently clean the walking surface. Platforms in the start boxes provide an easy way to lift the animals out of the apparatus when a training session or match has ended.

References