Burying and Burrowing Behavior in Male and Female Normal and 3xTg-AD Mice: A New Comprehensive Study Based on the Two-Zone Configuration.

Burying and burrowing are promising rodent-typical behaviors to model neuropsychiatric symptoms (NPS). However, the original tests could be insufficient to conclude which NPS are modeled. Here, we propose methodological modifications such as the two-zone configuration and dual analysis in the Marble Burying Test (MB). Also, a new Brief Burrowing Test (BB), a 20 min brief version of the Deacon’s Burrowing Test (DB). We comprehensively studied these behaviors in 12-month-old male and female mice with normal and Alzheimer’s disease (AD)-pathological aging. The results: 1) confirm our precedent report of sexual dimorphism, with enhanced burying in male 3xTg-AD mice; 2) describe for the first time burrowing behavior in 3xTg-AD mice and its sex dependence; 3) regardless of the pattern, MB and BB reflected a goal-directed rather than an indiscriminate digging; 4) using the MB and BB to model anxiety-like behavior it’s not recommended; 5) burying and burrowing represent a repetitive rather than a stereotyped-like or perseverative behavior. In addition: 1) burying and burrowing behavioral patterns are alike, connected by several correlations; 2) the two-zones configuration is a useful tool to assess the intentionality of the burying and burrowing behaviors and to perform a more accurate screening of the NPS modeled by them.