Topic: In vivo fiber photometry

Dopamine (DA) ramps are gradual increases in DA concentration observed during motivated behavior, contrasting with phasic DA release typically associated with signaling reward prediction errors (RPE). While RPE-related DA transients align with traditional models of reinforcement learning, where DA encodes the difference between expected and received rewards, dopamine ramps are less understood. Previous research demonstrated that DA ramps occur both at the level of DA cell bodies in the ventral tegmental area (VTA) and at the axon terminals in the nucleus accumbens (NAc), specifically in the me

Abnormal reward and threat processing are key players in psychiatric conditions such as eating disorders, addiction or depression. These functions are strongly regulated by the nucleus accumbens shell (NAcSh) which integrates emotional signals to regulate motor output. Historically the NAcSh was thought to consist of 2 pathways: dopamine 1 and 2 receptor-expressing striatal projection neurons (D1, D2-SPNs) which promoted reward and aversive behavior, respectively. Yet recent work has revealed that both cell types can promote either reward or aversion, depending on the NAcSh subregion or input/