Psychology Commons^™

The Role Of Glutamate Neurotransmission In The Ventral Tegmental Area In The Expression Of Conditioned Approach Learning, Priscila Hachimine-Merli

Dissertations, Theses, and Capstone Projects

Conditioned stimuli (CSs) come to function as CSs by acquiring the capacity to activate the same mesocorticolimbic dopamine (DA) neurons activated by primary rewards, producing conditioned activation of these neurons and their associated motivational states. This model stipulates that CSs activate mesocorticolimbic DA systems through the activation of glutamate receptors on DA neurons in the ventral tegmental area (VTA). We tested the hypothesis that glutamate receptor stimulation in the VTA is necessary for the expression of conditioned approach. Rats were tested in a conditioned approach protocol that consisted of 7 consecutive conditioning sessions (light presentations and food were paired), one …

The Nucleus Accumbens Core Dopamine D1 And Glutamate Ampa/Nmda Receptors Play A Transient Role In The Performance Of Pavlovian Approach Behavior, Veronica Dobrovitsky

Dissertations, Theses, and Capstone Projects

The role of the nucleus accumbens core (NAc core) continues to be redefined with newly acquired data on neurochemical mechanisms mediating the learning and performance of behavior. Previous empirical data showed that dopamine transmission at the D1 receptor (D1R) plays a transient role in the expression of learned Pavlovian approach behavior. Here we show that, prior to overtraining, dopamine activity at D1Rs specifically within the NAc core is critical for the performance of approach behavior elicited by the recently-acquired reward-paired cue. Blockade of D1Rs in the NAc core, but not the dorsomedial striatum or NAc shell, disrupted approach responses during …

Roles Of Gabab, Muscarinic And Nicotinic Receptor Signaling In The Acquisition And Expression Of Fructose And Fat-Conditioned Flavor Preferences And Acquisition Of Quinine-Conditioned Flavor Avoidances In Rats, Francis M. Rotella

Dissertations, Theses, and Capstone Projects

In addition to increased intake of sweet solutions by mammals, learning, particularly classically-conditioned “Pavlovian-like” learning, also plays an important role. An orosensory conditioned flavor preference (CFP) can be elicited by pairing one novel flavor (conditioned stimulus, CS+) with a fructose solution and a second novel flavor (CS-) with a saccharin solution. Rats will prefer the CS+ flavor in a subsequent 2-bottle choice test with both flavors mixed in saccharin. Previous pharmacological analyses revealed that systemic administration of dopamine (DA) D1 and D2 as well as NMDA, but not opioid, receptor antagonists eliminated the acquisition (learning) of fructose-CFP. Further, expression of …

Activation And Habituation Of The Cingulate Cortex During Emotion Processing In Healthy Controls, Borderline, And Schizotypal Personality Disorder, Emily Balevich

Dissertations, Theses, and Capstone Projects

Disturbances in emotional functioning are central features of the clinical profiles of both borderline and schizotypal personality disorder (BPD and SPD, respectively). BPD is characterized by a high sensitivity to emotional stimuli and unusually strong and long-lasting reactions, indicative of impaired habituation to emotional stimuli (Linehan, 1993). Previous research suggests that SPD patients demonstrate limbic hyper-reactivity to unpleasant stimuli, at least initially, but intact habituation to repeated presentation of unpleasant stimuli (Hazlett et al., 2012). The cingulate cortex supports various aspects of emotion processing and regulation, and abnormalities of this region have been related to emotion dysfunction in SPD and …

Understanding The Role Of The Ventrolateral Prefrontal Cortex In Emotional Memory Using Transcranial Direct Current Stimulation And Transcranial Magnetic Stimulation, R. Rachel Weintraub-Brevda

Dissertations, Theses, and Capstone Projects

Emotional stimuli can have both beneficial and detrimental effects on memory, such that emotional stimuli can be distracting from current neutral working memory goals, while also leading to enhanced episodic memory for the distracting emotional stimuli. Recent evidence suggests that the ventrolateral prefrontal cortex (VLPFC) has multiple roles in the enhancing effects of emotion on memory through top-down/controlled processes, including 1) coping with negative distraction and 2) elaborative encoding of negative information. Additionally, previous research has alluded to hemispheric differences in the VLPFC (Chapter 1). However, previous research has been correlational, with no strong laterality tests of the VLPFC. Two …

Sex Differences In The Anxiety Effects Of Cannabinoids, Helen T. French

Dissertations, Theses, and Capstone Projects

Aim: Anxiety disorders are twice as common among women, and those with anxiety disorders are 2-3 times more likely to have a substance abuse disorder than the general populace. However, little data exists on the sexually dimorphic effects of cannabinoids. In male humans and rodents, low acute doses of cannabinoids are anxiolytic while high and/or chronic doses are anxiogenic. In the dose response curve (DRC), we examined whether the biphasic effects of cannabinoids observed in males are also present in females. In the CB1R antagonism study, CP55,940-induced CB1R activation was antagonized via the CB1R-selective antagonist rimonabant to test the hypothesis …

Dopamine D1 And D3 Receptor Polypharmacology In Cocaine Reward And Cocaine Seeking, Ewa J. Galaj

Dissertations, Theses, and Capstone Projects

Background: In the search for efficacious pharmacotherapies to treat cocaine addiction much attention has been given to agents targeting D1 or D3 receptors because of the involvement of these receptors in cocaine-related behaviors. D1 and D3 receptor partial agonists and antagonists have been shown to reduce cocaine reward, reinstatement of cocaine seeking and conditioned place preference (CPP) in rodents and non-human primates. However, translation of these encouraging results with selective D1 or D3 receptor agents has been limited due to a number of factors including toxicity, poor pharmacokinetic properties and extrapyramidal and sedative side effects.

Purpose: Given the …

Capturing The Attention Of Caregivers: Variability In Infant Vocalizations, Catharine A. Castelluccio De Diesbach

Dissertations, Theses, and Capstone Projects

The effect of variability in infant vocalizations on potential caregivers’ heart rate variability (HRV), facial expressions, and subjective ratings on emotional reactions and desire to approach the baby was examined in an evolutionary context. Recordings of non-canonical, canonical, fussing, and crying vocalizations were utilized to elicit physiological and self-reported reactions from sixty participants. Breastfeeding mothers, non-mothers at high estradiol point in menstrual cycle, non-mothers at low estradiol point in menstrual cycle, fathers, and non-fathers were included in the study. Participants wore Polar RS800 heart rate monitors, were video recorded for facial expression analysis, and filled out 11 point self-rating forms …

Estradiol, Substance P, And The Pi3k-Akt-Mtor Pathway In The Dorsal Horn Of The Spinal Cord During Inflammatory Pain, Zane Ferguson

Dissertations, Theses, and Capstone Projects

Pain is a critical survival mechanism that signals potential or actual damage, but it can become pathological when it persists beyond the injury. Chronic pain is a major health issue that affects 10-20% of the adult population and is found disproportionately in women. There are numerous, interacting mechanisms underlying this phenomenon. This study used female rats to investigate the impact of estrogens on sensory signaling by substance P, a neuropeptide that contributes to the development of chronic pain, and the PI3K-Akt-mTOR pathway, an intracellular mechanism of nervous system plasticity.