Behavioral Voluntary and Social Bioassays Enabling Identification of Complex and Sex-Dependent Pain-(-Related)...

Area of Science:

• Preclinical pain research
• Oncology
• Animal behavior

Background:

• Cancer-induced bone pain (CIBP) significantly impacts patient quality of life, yet effective treatments are limited.
• Rodent models are crucial for CIBP research, but pain assessment often relies on limited reflexive methods, hindering clinical translation.
• Improved preclinical models are needed to accurately capture CIBP complexity.

Purpose of the Study:

• To develop and validate a more accurate preclinical model for cancer-induced bone pain (CIBP) in rats.
• To investigate sex-specific differences in CIBP development using multimodal behavioral analysis.
• To explore the influence of social housing on pain-related behaviors in a CIBP model.

Main Methods:

• Utilized a multimodal battery of behavioral tests, including home-cage monitoring (HCM), to assess pain in rats with induced bone tumors.
• Administered Walker 256 mammary gland carcinoma cells or sham injections into the tibia of rats.
• Employed principal component analysis (PCA) to integrate and analyze diverse behavioral datasets.

Main Results:

• Discovered sex-specific differences in the establishment of the CIBP phenotype, with earlier onset in males.
• HCM revealed sensory-affective states in tumor-free rats housed with CIBP cagemates, indicated by mechanical hypersensitivity.
• The multimodal approach provided detailed, sex-specific, and social phenotyping of CIBP.

Conclusions:

• A multimodal behavioral assessment, including HCM and PCA, enhances the accuracy of preclinical CIBP models.
• The findings highlight the importance of considering sex and social context in CIBP research.
• This robust model facilitates mechanism-driven studies and targeted drug development for CIBP.