Categories of Wistar Rats Based on Anxiety Traits: A Study Using Factor and Cluster Method

Area of Science:

• Neuroscience
• Animal Behavior

Background:

• Variability in animal anxiety traits impacts neurobehavioral study outcomes.
• Standardizing animal categorization can enhance result reproducibility and reduce inter-laboratory variation.

Purpose of the Study:

• To identify distinct behavioral groups within a normal population of adult male Wistar rats.
• To categorize rats based on their anxiety and activity traits.

Main Methods:

• Anxiety traits were assessed using the elevated plus maze (EPM) and open field test (OFT).
• Exploratory factor and hierarchical cluster analyses were applied to behavioral responses.
• Derived clusters were compared to identify distinct behavioral phenotypes.

Main Results:

• Factor analysis of EPM and OFT parameters yielded two components: anxiety and activity.
• Cluster analysis of EPM data classified rats into three groups: high anxiety/low activity, medium anxiety/high activity, and low anxiety/medium activity.
• OFT cluster analysis identified an additional group: low anxiety/high activity, with distinct groupings from EPM.

Conclusions:

• EPM and OFT parameters can be used to classify rats into distinct anxiety and activity profiles.
• The rat groups identified by EPM and OFT were not identical, suggesting the tests may capture different facets of anxiety.
• This categorization offers a potential method to control for anxiety variations in neurobehavioral research.