Tonic or Phasic Stimulation of Dopaminergic Projections to Prefrontal Cortex Causes Mice to Maintain or Deviate from Previously Learned Behavioral Strategies
| Autor: | Tosha Patel, Ian Ellwood, Kevin J. Bender, Anthony T. Lee, Varun Wadia, Alayna T. Liptak, Vikaas S. Sohal |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Male
0301 basic medicine Stimulation Striatum Inbred C57BL Choice Behavior Medical and Health Sciences Tonic (physiology) Mice 0302 clinical medicine Prefrontal cortex Research Articles behavioral flexibility Behavior Animal musculoskeletal neural and ocular physiology General Neuroscience Dopaminergic Ventral tegmental area medicine.anatomical_structure dopamine learning and memory Psychology psychological phenomena and processes medicine.drug 1.1 Normal biological development and functioning Prefrontal Cortex perseveration Basic Behavioral and Social Science 03 medical and health sciences Reward Underpinning research Dopamine Behavioral and Social Science medicine Animals Learning Behavior Neurology & Neurosurgery Animal Dopaminergic Neurons Ventral Tegmental Area Psychology and Cognitive Sciences Neurosciences Association Learning Electric Stimulation Conditioned place preference Brain Disorders Mice Inbred C57BL 030104 developmental biology nervous system Nerve Net Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience, vol 37, iss 35 |
| ISSN: | 1529-2401 0270-6474 |
| Popis: | Dopamine neurons in the ventral tegmental area (VTA) encode reward prediction errors and can drive reinforcement learning through their projections to striatum, but much less is known about their projections to prefrontal cortex (PFC). Here, we studied these projections and observed phasic VTA-PFC fiber photometry signals after the delivery of rewards. Next, we studied how optogenetic stimulation of these projections affects behavior using conditioned place preference and a task in which mice learn associations between cues and food rewards and then use those associations to make choices. Neither phasic nor tonic stimulation of dopaminergic VTA-PFC projections elicited place preference. Furthermore, substituting phasic VTA-PFC stimulation for food rewards was not sufficient to reinforce new cue-reward associations nor maintain previously learned ones. However, the same patterns of stimulation that failed to reinforce place preference or cue-reward associations were able to modify behavior in other ways. First, continuous tonic stimulation maintained previously learned cue-reward associations even after they ceased being valid. Second, delivering phasic stimulation either continuously or after choices not previously associated with reward induced mice to make choices that deviated from previously learned associations. In summary, despite the fact that dopaminergic VTA-PFC projections exhibit phasic increases in activity that are time locked to the delivery of rewards, phasic activation of these projections does not necessarily reinforce specific actions. Rather, dopaminergic VTA-PFC activity can control whether mice maintain or deviate from previously learned cue-reward associations.SIGNIFICANCE STATEMENT Dopaminergic inputs from ventral tegmental area (VTA) to striatum encode reward prediction errors and reinforce specific actions; however, it is currently unknown whether dopaminergic inputs to prefrontal cortex (PFC) play similar or distinct roles. Here, we used bulk Ca2+ imaging to show that unexpected rewards or reward-predicting cues elicit phasic increases in the activity of dopaminergic VTA-PFC fibers. However, in multiple behavioral paradigms, we failed to observe reinforcing effects after stimulation of these fibers. In these same experiments, we did find that tonic or phasic patterns of stimulation caused mice to maintain or deviate from previously learned cue-reward associations, respectively. Therefore, although they may exhibit similar patterns of activity, dopaminergic inputs to striatum and PFC can elicit divergent behavioral effects. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|