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Opiate-Induced Neuroplastic Alterations To Dopamine Signaling In The Basolateral Amygdala-Prefrontal Cortical Pathway, Laura G. Rosen

Electronic Thesis and Dissertation Repository

Opiate addiction is a chronic disorder with high rates of relapse. The failure to maintain sobriety after prolonged abstinence is believed to be due in part to the persistence of potent memories associated with the drug-taking experience. Activation of these memories by re-exposure to drug-related cues can trigger craving in many individuals. Thus, understanding the neurobiological processes underlying the formation of these memories may provide insight into the persistence of addiction. The mammalian basolateral amygdala (BLA) and medial prefrontal cortex (mPFC) comprise a functionally interconnected circuit that is critical for processing opiate-related associative memories. There is some evidence that chronic …

Dopamine-Dependent Task Performance Over The Menstrual Cycle, Alexandra A. De La Rua

Electronic Thesis and Dissertation Repository

Estradiol (E2) has been found to influence dopamine (DA) activity in the nonhuman animal brain. While there has been very little research performed looking at E2’s effects on DA-related cognitive function in humans, recent research found that women tested during high E2 phases of the menstrual cycle had significantly better performance on a DA-dependent spatial working memory task, than women tested during the lowest E2 phase. The current study utilized the natural hormone fluctuations that occur over the menstrual cycle to determine if E2 is associated with DA-dependent task performance. Using a repeated measures design, 47 women completed a battery …

Mechanisms Underlying Executive Function Deficits, Sagar Jayawantrao Desai

Electronic Thesis and Dissertation Repository

In our daily life, we come across situations where we meet unanticipated challenges, we must take certain decisions, pay attention, be flexible and inhibit impulsive actions to achieve goal directed behaviour. During these processes, we unknowingly use sets of interdependent cognitive processes collectively called ‘executive function’. Executive function is mainly regulated by the frontal lobe. Impaired executive function is associated with disorders such as schizophrenia, Alzheimer’s disease, autism and attention deficit hyperactivity disorder (ADHD).

In this thesis, we investigated neurotransmitters and interactions among them regulating executive function. Further, we investigated mechanisms underlying those interactions mediating executive function in rats using …

Prefrontal Cortex Dopamine Transmission Regulates Emotional Memory Processing And Morphine Reward Salience: Implications For Post-Traumatic Stress Disorder And Addiction Comorbidity, Jing Jing Li

Electronic Thesis and Dissertation Repository

Post-Traumatic Stress Disorder (PTSD) and addiction are strongly comorbid. However, the underlying neural mechanisms by which traumatic memory recall may increase addiction liability are poorly understood. The inability to suppress memory recall related to either stressful or rewarding, drug-related experiences may be an underlying neuropsychological feature capable of triggering both PTSD or addiction-related behaviours. Our previous research has shown that transmission through dopamine (DA) D₄ and D₁ receptor subtypes (D₄R, D₁R) within the prefrontal cortex (PFC) strongly modulates emotional memory acquisition and recall (Lauzon et al., 2009). Using olfactory fear conditioning and morphine conditioned …