Open-field activity in mice as a function of ceiling height: A genotype-environment interaction

Area of Science:

• Behavioral Neuroscience
• Animal Behavior
• Rodent Models

Background:

• The open-field test is a standard method for assessing rodent behavior and anxiety.
• BALB/c mice are generally characterized by low activity levels in open-field tests.
• Environmental factors can significantly influence behavioral outcomes in animal studies.

Purpose of the Study:

• To investigate the impact of varying ceiling heights in an open-field test on the activity levels of three inbred mouse strains.
• To examine the interaction between genetic background (mouse strain) and environmental conditions (ceiling height) on open-field behavior.

Main Methods:

• Three inbred mouse strains (C57BL/6, DAB/2, BALB/c) were tested in a McClearn-type open-field apparatus.
• The open-field test was conducted with three different ceiling heights: 1-inch, 1 5/8-inch, and 36-inch.
• Locomotor activity was recorded and analyzed for each strain under each condition.

Main Results:

• All mouse strains exhibited increased activity as the ceiling height was reduced.
• A significant interaction was observed between mouse strain and ceiling height.
• BALB/c mice, usually the least active, showed the highest activity in the 1-inch ceiling height condition.

Conclusions:

• Environmental manipulation, specifically reduced ceiling height, can alter the typical behavioral patterns of inbred mouse strains.
• The results challenge the established view of consistently low open-field activity in BALB/c mice, emphasizing the role of environmental context.
• This strain-environment interaction provides crucial insights for interpreting behavioral data and designing future animal research.