Opposing Contributions of GABAergic and Glutamatergic Ventral Pallidal Neurons to Motivational Behaviors

Abstract

The ventral pallidum (VP) is critical for invigorating reward seeking and is also involved in punishment avoidance, but how it contributes to such opposing behavioral actions remains unclear. Here, we show that GABAergic and glutamatergic VP neurons selectively control behavior in opposing motivational contexts. In vivo recording combined with optogenetics in mice revealed that these two populations oppositely encode positive and negative motivational value, are differentially modulated by animal's internal state, and determine the behavioral response during motivational conflict. Furthermore, GABAergic VP neurons are essential for movements toward reward in a positive motivational context but suppress movements in an aversive context. In contrast, glutamatergic VP neurons are essential for movements to avoid a threat but suppress movements in an appetitive context. Our results indicate that GABAergic and glutamatergic VP neurons encode the drive for approach and avoidance, respectively, with the balance between their activities determining the type of motivational behavior.

Keywords: GABAergic neurons; glutamatergic neurons; negative motivation; positive motivation; punishment avoidance; reward seeking; ventral pallidum.