Carina Soares-Cunha, supported by the BIAL Foundation in the scope of project 175/20 – The role of nucleus accumbens in the perception of natural rewards, concluded that, in rodents, the optogenetic modullation of the D2-MSN-VP projections has different effects in the distinct phases of motivated behavior. The paper “Distinct roles of nucleus accumbens D2-MSN projections to ventral pallidum in different phases of motivated behavior” featuring these results was published in the journal Cell Reports.
Abstract
“The nucleus accumbens (NAc) is a key region in motivated behaviors. NAc medium spiny neurons (MSNs) are divided into those expressing dopamine receptor D1 or D2. Classically, D1- and D2-MSNs have been described as having opposing roles in reinforcement, but recent evidence suggests a more complex role for D2-MSNs. Here, we show that optogenetic modulation of D2-MSN to ventral pallidum (VP) projections during different stages of motivated behavior has contrasting effects in motivation. Activation of D2-MSN- VP projections during a reward-predicting cue results in increased motivational drive, whereas activation at reward delivery decreases motivation; optical inhibition triggers the opposite behavioral effect. In addition, in a free-choice instrumental task, animals prefer the lever that originates one pellet in opposition to pellet plus D2-MSN-VP optogenetic activation and vice versa for optogenetic inhibition. In summary, D2-MSN-VP projections play different, and even opposing, roles in distinct phases of motivated behavior.”
