Dopamine release in nucleus accumbens core during social behaviors in mice

Social behaviors are among the most important and rewarding motivational behaviors. How dopamine, a "reward" signal, releases in the nucleus accumbens (NAc) during social behaviors has become a topic of interest for decades. However, limitations in early recording methods, such as microdialysis, prevented a complete understanding of moment-to-moment dopamine responses during social behaviors. Here, we employ a genetically encoded dopamine sensor, GRABDA2h, to record dopamine activity in the NAc core in mice and find acute changes in extracellular dopamine levels during all three phases of social behaviors: approach, investigation and consummation. Dopamine release during approach phase correlates with animal's motivation towards the conspecific whereas its release during consummatory phase signals the valence of the experience. Furthermore, dopamine release during sexual and aggressive behaviors shows sex differences that correlate with the potential value of those experiences. Overall, our results reveal rich and temporally precise motivation and value information encoded by NAc dopamine during social behaviors and beyond.

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Sensitization of Rapid Dopamine Signaling in the Nucleus Accumbens Core and Shell After Repeated Cocaine in Rats

Journal of Neurophysiology ◽

10.1152/jn.00413.2010 ◽

2010 ◽

Vol 104 (2) ◽

pp. 922-931 ◽

Cited By ~ 32

Author(s):

Nii A. Addy ◽

David P. Daberkow ◽

Jeremy N. Ford ◽

Paul A. Garris ◽

R. Mark Wightman

Keyword(s):

Nucleus Accumbens ◽

Dopamine Release ◽

Cocaine Exposure ◽

Sprague Dawley ◽

Nucleus Accumbens Core ◽

Fast Scan Cyclic Voltammetry ◽

Uptake Inhibition ◽

Sprague Dawley Rats ◽

Dopamine Signaling

Repeated cocaine exposure and withdrawal leads to long-term changes, including behavioral and dopamine sensitization to an acute cocaine challenge, that are most pronounced after long withdrawal periods. However, the changes in dopamine neurotransmission after short withdrawal periods are less well defined. To study dopamine neurotransmission after 1-day withdrawal, we used fast-scan cyclic voltammetry (FSCV) to determine whether repeated cocaine alters rapid dopamine release and uptake in the nucleus accumbens (NAc) core and shell. FSCV was performed in urethane anesthetized male Sprague-Dawley rats that had previously received one or seven daily injections of saline or cocaine (15 mg/kg, ip). In response to acute cocaine, subjects showed increased dopamine overflow that resulted from both increased dopamine release and slowed dopamine uptake. One-day cocaine pre-exposure, however, did not alter dopaminergic responses to a subsequent cocaine challenge. In contrast, 7-day cocaine-treated subjects showed a potentiated rapid dopamine response in both the core and shell after an acute cocaine challenge. In addition, kinetic analysis during the cocaine challenge showed a greater increase in apparent Km of 7-day cocaine exposed subjects. Together, the data provide the first in vivo demonstration of rapid dopamine sensitization in the NAc core and shell after a short withdrawal period. In addition, the data clearly delineate cocaine's release and uptake effects and suggest that the observed sensitization results from greater uptake inhibition in cocaine pre-exposed subjects.

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