Beatrice K Leung

• UNSW Sydney

Cortico-striatal neurocircuits mediate goal-directed and habitual actions which are necessary for adaptive behaviour. It has recently been proposed that some of the core symptoms of autism spectrum disorder (ASD) and Gilles de la Tourette syndrome (GTS), such as tics and other repetitive behaviours, may emerge because of imbalances in these neuroci...

Obesity can disrupt how food-predictive stimuli control action performance and selection. These two forms of control recruit cholinergic interneurons (CIN) located in the nucleus accumbens core (NAcC) and shell (NAcS), respectively. Given that obesity is associated with insulin resistance in this region, we examined whether interfering with CIN ins...

The loss of neurons in parafascicular thalamus (Pf) and their inputs to dorsomedial striatum (DMS) in Lewy body disease (LBD) and Parkinson's disease dementia (PDD) have been linked to the effects of neuroinflammation. We found that, in rats, these inputs were necessary for both the function of striatal cholinergic interneurons (CINs) and the flexi...

Obesity can disrupt how food-predictive stimuli control action performance and selection. These two forms of control recruit cholinergic interneurons (CIN) located in the nucleus accumbens core (NAcC) and shell (NAcS), respectively. Given that obesity is associated with insulin resistance in this region, we examined whether interfering with CIN ins...

Cortico-striatal neurocircuits mediate goal-directed and habitual actions which are necessary for adaptive behaviour. It has recently been proposed that some of the core symptoms of autism spectrum disorder (ASD) and Gilles de la Tourette syndrome (GTS), such as tics and repetitive behaviours, may emerge because of imbalances in these neurocircuits...

The basolateral amygdala (BLA) complex receives dense cholinergic projections from the nucleus basalis of Meynert (NBM) and the horizontal limb of the diagonal band of Broca (HDB). The present experiments examined whether these projections regulate the formation, extinction, and renewal of fear memories. This was achieved by employing a Pavlovian f...

The loss of neurons in parafascicular thalamus (Pf) and of their inputs to dorsomedial striatum (DMS) are associated with Lewy body disease (LBD) and Parkinsons disease dementia (PDD) and have been linked to the effects of neuroinflammation. In rats, these inputs regulate the function of striatal cholinergic interneurons (CINs) that are necessary f...

The role of the hippocampus in goal-directed action is currently unclear; studies investigating this issue have produced contradictory results. Here we reconcile these contradictions by demonstrating that, in rats, goal-directed action relies on the dorsal hippocampus, but only transiently, immediately after initial acquisition. Furthermore, we fou...

Predictive learning exerts a powerful influence over choice between instrumental actions. Nevertheless, how this learning is encoded in a sufficiently stable manner to influence choices that can occur much later in time is unclear. Here, we report that the basolateral amygdala (BLA) encodes predictive learning and establishes the memory necessary f...

Rats use spatiotemporal features of the environment to navigate to a goal, but whether representations of ‘action space’ are necessary for non-navigational goal-directed actions is unknown. We addressed this question by assessing goal-directed action control across contexts and under hippocampal inactivation and found that such actions do indeed re...

Outcome-specific Pavlovian-instrumental transfer (PIT) demonstrates the way that reward-related cues influence choice between instrumental actions. The nucleus accumbens shell (NAc-S) contributes critically to this effect, particularly through its output to the rostral medial ventral pallidum (VP-m). Using rats, we investigated in two experiments t...

Considerable evidence suggests that distinct neural processes mediate the acquisition and performance of goal-directed instrumental actions. Whereas a cortical-dorsomedial striatal circuit appears critical for the acquisition of goal-directed actions, a cortical-ventral striatal circuit appears to mediate instrumental performance, particularly the...

The posterior dorsomedial striatum (pDMS) is essential for the acquisition and expression of the specific response-outcome (R-O) associations that underlie goal-directed action. Here we examined the role of a pathway linking the basolateral amygdala (BLA) and pDMS in such goal-directed learning. In Experiment 1, rats received unilateral lesions of...

The nucleus accumbens shell (NAc-S) plays an important role in the way stimuli that predict reward affect the performance of, and choice between, goal-directed actions in tests of outcome-specific Pavlovian-instrumental transfer (PIT). The neural processes involved in PIT downstream of the ventral striatum are, however, unknown. The NAc-S projects...

Two motivational processes affect choice between actions: (1) changes in the reward value of the goal or outcome of an action and (2) changes in the predicted value of an action based on outcome-related stimuli. Here, we evaluated the role of μ-opioid receptor (MOR) and δ-opioid receptor (DOR) in the nucleus accumbens in the way these motivational...

Considerable evidence suggests that choice between goal-directed actions depends on two incentive processes encoding the reward value of the goal or outcome and the predicted value of an action based on outcome-related stimuli. Although incentive theories generally assume that these processes are mediated by a common associative mechanism, a number...