PhenoWorld: a new paradigm to screen rodent behavior

Area of Science:

• Neuroscience
• Animal Behavior
• Psychiatry

Background:

• Animal models are crucial for understanding depression but face challenges in measuring behavioral phenotypes.
• Existing models struggle to capture the full spectrum of depressive symptoms, especially hedonic deficits.

Purpose of the Study:

• To introduce and validate the PhenoWorld (PhW), an ethologically enriched environment for enhanced rodent depression modeling.
• To assess the sensitivity of PhW-monitored behaviors to stress and antidepressant treatments.

Main Methods:

• Rats were housed in the PhenoWorld (PhW) or standard conditions and exposed to unpredictable chronic mild stress (uCMS) and antidepressants.
• Continuous automated monitoring of feeding, locomotor activity, sleep, and social behavior within the PhW.
• Behavioral phenotyping using a battery of emotional and cognitive tests, including the forced swimming test.

Main Results:

• PhW housing amplified behavioral differences induced by uCMS, showing increased behavioral despair, sleep disturbances, and reduced social interaction.
• Spontaneous behaviors in the PhW, such as seeking food or using running wheels, served as sensitive indicators of depressive-like states.
• The PhW paradigm demonstrated significant discriminative power in screening rodent hedonic behavior.

Conclusions:

• The PhenoWorld (PhW) provides a powerful and sensitive ethological enriched environment for modeling depression in rodents.
• Automated monitoring of behaviors within the PhW significantly enhances the detection of stress-induced depressive-like phenotypes.
• This model offers improved insights into rodent hedonic behavior and its disruption in depression.