title: A novel strategy for dissecting goal-directed action and arousal components of motivated behavior with a progressive hold-down task.
abstract: Motivation serves 2 important functions: It guides actions to be goal-directed, and it provides the energy and vigor required to perform the work necessary to meet those goals. Dissociating these 2 processes with existing behavioral assays has been a challenge. In this article, we report a novel experimental strategy to distinguish the 2 processes in mice. First, we characterize a novel motivation assay in which animals must hold down a lever for progressively longer intervals to earn each subsequent reward; we call this the progressive hold-down (PHD) task. We find that performance on the PHD task is sensitive to both food deprivation level and reward value. Next, we use a dose of methamphetamine (METH) 1.0 mg/kg, to evaluate behavior in both the progressive ratio (PR) and PHD tasks. Treatment with METH leads to more persistent lever pressing for food rewards in the PR. In the PHD task, we found that METH increased arousal, which leads to numerous bouts of hyperactive responding but neither increases nor impairs goal-directed action. The results demonstrate that these tools enable a more precise understanding of the underlying processes being altered in manipulations that alter motivated behavior.
authors.affiliation: Department of Psychology, Columbia University.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Bailey
authors.affiliation: Department of Psychology, Columbia University.
authors.forename: Greg
authors.initials: G
authors.lastname: Jensen
authors.affiliation: Department of Psychiatry, Columbia University.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Taylor
authors.affiliation: Department of Psychology, Barnard College.
authors.forename: Chris
authors.initials: C
authors.lastname: Mezias
authors.affiliation: Department of Psychology, Columbia University.
authors.forename: Cait
authors.initials: C
authors.lastname: Williamson
authors.affiliation: Department of Psychology, Barnard College.
authors.forename: Rae
authors.initials: R
authors.lastname: Silver
authors.affiliation: Department of Psychiatry, Columbia University.
authors.forename: Eleanor H
authors.initials: EH
authors.lastname: Simpson
authors.affiliation: Department of Psychology, Barnard College.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Balsam
mesh_terms: D000818:Animals; D001143:Arousal / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D005260:Female; D005508:Food Deprivation; D006040:Goals; D008694:Methamphetamine / Q000494:pharmacology; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D009042:Motivation / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D009483:Neuropsychological Tests; D012055:Reinforcement Schedule; D012201:Reward
chemical_list: D000697:Central Nervous System Stimulants; D008694:Methamphetamine