From Reward to Cue: Developmental Changes in Nucleus Accumbens and Dopamine Signaling from Adolescence to Adulthood
Year: 2026
Type: article
Abstract: Why does the adolescent brain, despite its heightened sensitivity to reward, appear less captivated by cues that predict it?Adolescence is a period marked by increased reward seeking, impulsivity, and risk-taking, yet adolescents are less likely than adults to approach reward-associated cues.This apparent contradiction may provide an important clue to how the developing brain regulates motivation and why adolescence is a period of vulnerability to behaviors that can have lasting consequences.In a new study, Herring et al. show that the transition from adolescence to adulthood is accompanied by a shift in nucleus accumbens (NAc) activity moving from the reward itself toward the cue that predicts it, alongside changes in dopamine signaling.These findings suggest that maturation may change not simply how strongly rewards are valued, but how the brain assigns motivational value to the signals that surround them.One way to study this adolescent paradox is through behavior in rodent models.During Pavlovian conditioning, a cue such as a lever predicts the delivery of a food reward (Fitzpatrick and Morrow, 2016).Some animals approach and interact with the cue itself, a behavior known as sign tracking (ST).Others approach the location where the reward will be delivered, known as goal tracking (GT).ST is thought to reflect the attribution of incentive salience to a reward-predictive cue, where the cue itself becomes motivationally attractive.This distinction is relevant to understanding reward-driven and potentially maladaptive behaviors, because ST has been associated with impulsivity, risk-taking, and vulnerability to drug-seeking behavior (Tomie et al., 2008).Surprisingly, adolescent animals are generally less likely than adults to sign track and more likely to goal track (Rode et al., 2020).This is striking given that adolescence is also associated with increased sensitivity to rewards.Rather than being uniformly more responsive to reward-related information, adolescents may process components of a reward experience differently.The study directly examined this possibility by following rats from adolescence into adulthood while examining behavior and neural activity in the NAc (Herring et al., 2026).The researchers first trained adolescent rats on a Pavlovian conditioned approach task while recording the activity of individual NAc neurons.The same animals were then tested again in adulthood.In a separate group, they used the fluorescent dopamine sensor GRAB DA to measure dopamine release in the NAc during the same task.This combination allowed examination of both the behavioral transition from adolescence to adulthood, as well as the underlying neural circuitry.Most adolescent rats were goal-trackers (GTs) or intermediate animals rather than strong sign-trackers (STs).When retested as adults, many of these animals increased their ST and decreased their GT.However, animals that already exhibited strong ST during adolescence tended to retain that behavior into adulthood (Herring et al., 2026).The neural findings provide a possible explanation for this transition.Among adolescent GTs and intermediate animals, reward-evoked NAc activity peaked during adolescence and declined in adulthood.Meanwhile, cue-evoked NAc activity continued to increase
Source: eNeuro
Author: Hannah Nicholson
Institutions: Western University, University of Pittsburgh
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,925
OpenAlex ID: W7222027732