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BACKGROUND Recent evidence suggests that the neural correlates of reversal learning are localised to the orbitofrontal cortex whereas studies on the contribution of the medial prefrontal cortex to this capacity have produced equivocal results. This study examines the behavioural effects of selective lesions centred on orbitofrontal, infralimbic and(More)
We have recently demonstrated that systemic administration of 5-HT(2C) and 5-HT(2A) receptor antagonists significantly enhanced and impaired spatial reversal learning, respectively. In this study, the role of 5-HT(2C) and 5-HT(2A) receptor subtypes in the mediation of these opposing effects was further investigated with respect to neuroanatomical(More)
RATIONALE Dopamine is strongly implicated in the ability to shift behavior in response to changing stimulus-reward contingencies. OBJECTIVES We investigated the effects of systemic administration of the D2/D3 receptor agonist quinpirole (0.1, 0.3 mg/kg), the D2/D3 receptor antagonist raclopride (0.1, 0.3 mg/kg), the selective D3 antagonist nafadotride(More)
OBJECTIVE The serotonergic system is implicated in the pathophysiology of obsessive-compulsive disorder (OCD). However, the distinct role of serotonin (5-HT) receptor subtypes remains unclear. This study investigates the contribution of 5-HT2A and 5-HT2C receptors in the modulation of persistence in the reinforced spatial alternation model of OCD. METHODS(More)
Several axis-I neuropsychiatric disorders are characterised by repetitive motor habits suggestive of underlying inhibitory dyscontrol, and may constitute members of a putative obsessive-compulsive (OC) spectrum. Notable examples include obsessive-compulsive disorder (OCD) and trichotillomania (repetitive hair-pulling). Multiple tiers of evidence link these(More)
Serotonin (5-hydroxytryptamine, or 5-HT) is strongly implicated in the ability to shift behavior in response to changing stimulus-reward contingencies. However, there is little information on the contribution of different 5-HT receptors in reversal learning. Thus, we investigated the effects of systemic administration of the 5-HT(2A) antagonist M100907 (0,(More)
Disturbances in attentional processes are a common feature of several psychiatric disorders such as schizophrenia, attention deficit/hyperactivity disorder and Huntington's disease. The use of animal models has been useful in defining various candidate neural systems thus enabling us to translate basic laboratory science to the clinic and vice-versa. In(More)
Obsessive-compulsive disorder (OCD) is characterized by obsessions (intrusive thoughts) and compulsions (repetitive ritualistic behaviours) leading to functional impairment. Accumulating evidence links these conditions with underlying dysregulation of fronto-striatal circuitry and monoamine systems. These abnormalities represent key targets for existing and(More)
BACKGROUND In spite of recent enrichment of neurochemical and behavioural data establishing a neuroprotective role for lithium, its primary effects on cognitive functioning remain ambiguous. This study examines chronic lithium effects on spatial working memory and long-term retention. METHODS In three discrete experiments, rats subjected to 30 daily(More)
Trichotillomania is a disorder characterized by repetitive hair pulling, leading to noticeable hair loss and functional impairment. This paper provides an overview of what is known of trichotillomania from several perspectives. We begin by considering historical descriptions of hair pulling that ultimately contributed to the inclusion of trichotillomania as(More)