Inflammation-induced motivational changes: Perspective gained by evaluating positive and negative valence systems

Area of Science:

• Neuroscience
• Behavioral Science
• Psychiatry

Background:

• Inflammation significantly affects motivated behavior, notably in conditions like inflammation-induced depression.
• Understanding neurobehavioral processes is crucial for deciphering motivation changes during inflammation.

Purpose of the Study:

• To investigate how inflammation impacts basic neurobehavioral processes underlying approach and avoidance motivation.
• To identify the mediating factors, such as effort and reward valuation, in inflammation-related motivational shifts.

Main Methods:

• Objective evaluation of basic neurobehavioral processes related to motivation.
• Assessment of approach and avoidance behaviors under inflammatory conditions.
• Analysis of effort valuation and reward valuation changes.

Main Results:

• Inflammation generally reduces approach motivation and enhances avoidance motivation.
• Increased effort valuation significantly mediates the reduction in approach motivation.
• Inflammation intensifies the averseness of negative stimuli and enhances stimulus contrast.

Conclusions:

• Inflammation-induced depression involves significant alterations in motivated behavior, primarily affecting approach and avoidance tendencies.
• Midbrain dopaminergic neurotransmission to the ventral striatum likely mediates these motivational changes, though the mechanism for enhanced stimulus contrast remains unclear.