Deciphering the role of mesocortical dopamine in motivated behaviors

Conférence du Centre de recherche CERVO
Date et heure: 
Ven, 2024-04-05 11:00
Une conférence de: 
Cody Siciliano
Affiliation: 

Assistant Professor

Vanderbilt University

Department of Pharmacology

 

Description: 

Mesocortical dopamine activity is thought to be critical for fundamental neurobiological processes including valence coding and decision-making. Despite enduring interest in this pathway, the stimuli and conditions that engage mPFC dopamine release have remained enigmatic due to inherent limitations in conventional methods for dopamine monitoring which have prevented real-time in vivo observation. Here, using a fluorescent dopamine sensor enabling time-resolved recordings of cortical dopamine activity in freely behaving mice, we reveal the coding properties of this system and demonstrate that mPFC dopamine dynamics conform to a selective attention signal. Contrary to the long-standing theory that mPFC dopamine release preferentially encodes aversive and stressful events, we observed robust dopamine responses to both appetitive and aversive stimuli which dissipated with increasing familiarity irrespective of stimulus intensity. We found that mPFC dopamine does not evolve as a function of learning but displays striking temporal precedence with second-to-second changes in behavioral engagement, suggesting a role in allocation of attentional resources. Systematic manipulation of attentional demand revealed that quieting of mPFC dopamine signals the allocation of attentional resources towards an expected event which, upon detection triggers a sharp dopamine transient marking the transition from decision-making to action. The proposed role of mPFC dopamine as a selective attention signal is the first model based on direct observation of time-resolved dopamine dynamics and reconciles decades of competing theories.

Local: 
F-1455
Lieu: 
Centre de recherche CERVO Brain Research Centre, 2601, de la Canardière Québec (Québec) CANADA G1J 2G3

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