Topic: nucleus accumbens core

Learning to predict rewards based on environmental cues is essential for survival. It is widely believed that animals learn to predict rewards by updating predictions whenever the outcome deviates from expectations. Such violations of predictions are called reward prediction errors (RPEs). RPEs are the critical teaching signal in the most widely accepted model for associative learning—temporal difference reinforcement learning (TDRL). As TDRL RPE has been successful at explaining the activity dynamics of dopamine, it has become the dominant theory of dopamine’s role as the critical regulator o

The mesolimbic dopamine system is believed to regulate both reinforcement learning and motivation to obtain rewards. A central question is how the mesolimbic dopamine system influences these distinct functions. A classical neural circuit model proposes a two-component system in which dopamine release in the nucleus accumbens core encodes prediction error signals to regulate reinforcement learning while dopamine release in the nucleus accumbens shell signals incentive salience and promotes motivated responses. Here we record bulk calcium dynamics in projection-specific ventral tegmental area (V

In natural environments, animals must efficiently allocate their choices across multiple concurrently available resources when foraging, a complex decision-making process not fully captured by existing models. To understand how animals learn to navigate this challenge we developed a novel paradigm in which untrained, water-restricted mice were free to sample from six options rewarded at a range of deterministic intervals and positioned around the walls of a large arena. Combining core features of quantitative models of foraging and decision-making, we developed a novel reinforcement learning (

Aims: Sign-tracking (ST) behavior is a phenotype characterized by attraction to a reward-associated stimulus due to incentive salience attribution and it’s considered an endophenotype of vulnerability to drug addiction. Such phenotype is dependent on Dopamine (DA) transmission within the Nucleus Accumbens core (NACc), as DA suppression prevents both its development and expression. However, previous studies suggested the hypothesis that ST behavior can be dependent on different neural mechanisms in two inbred strains of C57BL/6J (C57) and DBA/2J (DBA) mice, which have known differences in their

Aversive events in our environment shape our behaviours. Instrumental behaviours are punished when an action results in an aversive event. Yet there are instances where behaviours appear inappropriately sensitive to potential threats. The neural underpinnings of these inappropriate behaviours are poorly understood. In a conditioned punishment task, we trained rats to press two levers for pellets. Their responding suppressed on one lever when it also earned a conditioned stimulus (CS+) that was paired with a footshock, whilst responding continued on the other lever that earned a neutral conditi

Pre-clinical studies on drug addiction and relapse often overlooked volitional social interactions, which are of critical importance in human addiction. Recently, it has been demonstrated that social choice-based voluntary abstinence in rats attenuates the emergence of incubation of methamphetamine (Meth) craving relative to rats subjected to a forced abstinence. In the current study we investigated the molecular mechanisms by which social choice-based voluntary abstinence prevents the incubation of craving. An important mechanism driving cue-induced craving from psychostimulants in forced abs

In humans with alcohol use disorders (AUD), stress often triggers craving and relapse to alcohol drinking. This characteristic can be modeled in laboratory using stress-induced reinstatement. Here, we showed that in both male and female rats, an increased sensitivity to develop stress-induced reinstatement is promoted by decreased expression of Prdm2, a gene that encodes histone methyltransferase, due to alcohol-induced DNA hypermethylation in the dorsomedial prefrontal cortex (dmPFC). Consistent with our preclinical data, we found that humans with AUD had lowered PRDM2 expression in the prefr