Reduction of Submissive Behavior Model for antidepressant drug activity testing: study using a video-tracking system

Area of Science:

• Neuroscience
• Animal Behavior
• Pharmacology

Background:

• Submissive behavior in rats can be quantified using observer-based scoring in the Reduction of Submissive Behavior Model.
• Previous studies demonstrated that antidepressant treatments selectively reduce submissive behavior.

Purpose of the Study:

• To validate the use of automated video-tracking for assessing antidepressant effects on rat submissive behavior.
• To extend previous findings to other antidepressant and non-antidepressant drugs.

Main Methods:

• A multiple-subject video-tracking system was employed to automate the scoring of submissive behavior in rats during food competition tests.
• Rats were treated with imipramine, fluoxetine, maprotiline, or naltrindole for five weeks.
• Automated scoring allowed for simultaneous observation of multiple rat pairs.

Main Results:

• Automated scoring confirmed previous findings with imipramine and fluoxetine, showing significant reductions in submissive behavior.
• Maprotiline demonstrated antidepressant-like effects, reducing submissive behavior similarly to imipramine and fluoxetine.
• Naltrindole, a delta-opioid antagonist, did not reduce submissive behavior, highlighting the test's selectivity.

Conclusions:

• Automated video tracking is a reliable and efficient method for quantifying antidepressant effects on rat submissive behavior.
• The Reduction of Submissive Behavior Model, when assessed via automated scoring, remains selective for antidepressant activity.
• These findings support the use of this model in preclinical antidepressant drug discovery.