Ventral pallidum neurons projecting to the ventral tegmental area reinforce but do not invigorate reward-seeking behavior
Dakota Palmer,
Christelle A. Cayton,
Alexandra Scott,
Iris Lin,
Bailey Newell,
Anika Paulson,
Morgan Weberg,
Jocelyn M. Richard
Affiliations
Dakota Palmer
Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Medical Discovery Team on Addiction, University of Minnesota, Minneapolis, MN 55455, USA
Christelle A. Cayton
Medical Discovery Team on Addiction, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
Alexandra Scott
Medical Discovery Team on Addiction, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
Iris Lin
Medical Discovery Team on Addiction, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
Bailey Newell
Medical Discovery Team on Addiction, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
Anika Paulson
Medical Discovery Team on Addiction, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
Morgan Weberg
Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
Jocelyn M. Richard
Medical Discovery Team on Addiction, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Corresponding author
Summary: Reward-predictive cues acquire motivating and reinforcing properties that contribute to the escalation and relapse of drug use in addiction. The ventral pallidum (VP) and ventral tegmental area (VTA) are two key nodes in brain reward circuitry implicated in addiction and cue-driven behavior. In the current study, we use in vivo fiber photometry and optogenetics to record from and manipulate VP→VTA in rats performing a discriminative stimulus task to determine the role these neurons play in invigoration and reinforcement by reward cues. We find that VP→VTA neurons are active during reward consumption and that optogenetic stimulation of these neurons biases choice behavior and is reinforcing. Critically, we find no encoding of reward-seeking vigor, and optogenetic stimulation does not enhance the probability or vigor of reward seeking in response to cues. Our results suggest that VP→VTA activity is more important for reinforcement than for invigoration of reward seeking by cues.
