Topic: Pavlovian conditioning

Pavlovian conditioning describes a form of associative learning wherein initially neutral cues acquire motivational value through repeated pairing with rewards. Two learning profiles have been identified in how such cues acquire value and bias performance: sign-trackers, i.e., individuals who attribute high incentive (or attractive) value to reward-predictive cues, and goal-trackers, i.e., individuals who acquire the predictive value of cues but use it to directly approach the reward. The acquisition of incentive value seems crucial in making sign-trackers maladaptive, favouring behaviours lik

Accumulating evidence shows that dopaminergic neurons of the ventral tegmental area (VTA) are crucial for rewarding and aversive responses. The activity of these neurons is intricately regulated by various neuropeptides, one of which is the endogenous opioid dynorphin. It is thought that the main source of dynorphin in the VTA arises from nucleus accumbens (NAc) D1-MSNs, and that dynorphin acts primarily on kappa opioid receptors (KORs), serving as negative feedback mechanism to modulate dopamine release. Thus, dynorphin signals may regulate dopamine dynamics and, in this way, contribute for r

The nucleus accumbens (NAc) is a key brain region involved in rewarding and aversive responses. The NAc is mainly composed of GABAergic medium spiny neurons (MSNs) expressing either dopamine receptor D1 or D2. Some studies propose an antagonist role of D1- and D2-MSNs, whereas others suggest that both populations play distinct, but not necessarily opposing roles in valence behaviour.Here, we used deep brain 1-photon calcium imaging to follow NAc D1- or D2-MSN activity in response to opposing valence stimuli and during associative learning. In addition, we used optogenetics to further unravel t

We aim to advance the mechanistic understanding of pain anticipation by investigating how the human cortical motor system learns to prepare for aversive somatosensory events. In this study, we tracked how neural oscillations and corticospinal excitability reflect the acquisition and reversal of pain expectations. Using a Pavlovian conditioning task, participants learned to anticipate the occurrence of lateralized aversive shocks. Specifically, during acquisition neutral visual stimuli predicted shocks to either the left (CS+L) or right (CS+R) arm, while another stimulus (CS-) never predicted s

Reward-paired cues through pavlovian conditioning can impact instrumental reward-seeking behaviour in a key concept called pavlovian instrumental transfer (PIT). Three categories of transfer effects emerge from a PIT protocol using a full transfer paradigm. In the specific same condition, instrumental actions paired with the same reward as a cue are enhanced, while in the specific different transfer effect, there is a reduced instrumental response when this cue is paired with another outcome. Lastly, the expression of general transfer refers to the motivational effect of the cue to enhance lev

We aimed to investigate the role of dopamine (DA), acetylcholine (ACh), norepinephrine (NE) and serotonin (5-HT) in associative learning and the correlation of their release with the reward prediction error (RPE). To address this, we trained mice on a sound detection Pavlovian conditioning task with a 50% reward schedule that allowed examining clean representations of postivite (rewarded trials) and negative RPE (reward omission trials), while we measured DA, ACh, NE and 5-HT release by fiber photometry. Behavioral updating of value representations based on the outcome of the previous trial wa

Cue reactivity is an important predictor of addiction and relapse. However, it is unclear to what degree it is determined by a trait-like propensity to attribute incentive salience to cues. Animal studies have uncovered that individual variation in such a trait-like propensity expressed behaviorally as “sign-tracking” (ST) is associated with addiction-relevant behavioral and neurobiological features. The current study is first to examine the association between ST and cue reactivity in regular electronic cigarette (ECIG) users. Thirty-seven moderately dependent ECIG users (20 females) were cha

Timely reaction to salient stimuli is essential for survival. The subcortical thalamic-basolateral amygdala (BLA) pathway ensures rapid processing. Here, we show that BLA neuronal, and thalamic axonal activity mirror the defensive behaviour evoked by an innate-visual-threat as well as an auditory-learned-threat. Perturbing this pathway compromises defensive responses to both threats. Our side-by-side examination highlights innate and learned threat processing in the subcortical amygdala pathway, thus providing new fundamental insights. Next, we examined the role of homo- and hetero-synaptic pl