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- All Subjects: Addiction
- Creators: Gipson-Reichardt, Cassandra
Description
Nicotine use is an outstanding public health problem with associated social and economic consequences. Nicotine is an active alkaloid compound in tobacco and is recognized as a psychoactive drug. Preclinically, nicotine addiction and relapse can be modeled using a self-administration-reinstatement paradigm. Here, we used a nicotine self-administration and contingent cue-induced reinstatement model to examine rapid, transient synaptic plasticity (t-SP) induced by nicotine cue-triggered motivation. Although preliminary, treatment with the NMDA GluN2B subunit antagonist, ifenprodil, reduced reinstated nicotine seeking, and increased the percentage of spines with smaller head diameters. Thus, future studies are needed to fully parse out the role of NAcore GluN2B receptors in cued nicotine seeking and t-SP.
ContributorsMccallum, Joseph John (Author) / Gipson-Reichardt, Cassandra (Thesis director) / Neisewander, Janet (Committee member) / Olive, Michael Foster (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The serotonin (5-hydroxytryptamine, 5-HT) system is implicated in the study of drug addiction. Of the 14 known serotonin receptor subtypes, the 5-HT7R is the most recently discovered and, therefore, one of the least rigorously studied. However, the 5-HT7R has been shown to play a role in multiple psychiatric conditions, including depression, anxiety, and alcoholism. This is not surprising, as the 5-HT7R is expressed in brain regions associated with emotion and reward, such as the amygdala, dorsal raphe nucleus, and striatum. MC-RG19 is a novel 5-HT7R antagonist which has >114-fold selectivity for the 5-HT7 over other serotonin receptors. This compound was developed by our collaborators at the Temple University School of Pharmacy. Due to this specificity, and the implications of the 5-HT7 in behavior, we hypothesized that MC-RG19 would have an effect on addiction-related behaviors. We investigated the effects of MC-RG19 on spontaneous locomotion, cue-induced reinstatement, and cocaine/sucrose multiple schedule self-administration. We observed a dose-dependent decrease in spontaneous locomotor activity with significance at a MC-RG19 dose of 10 mg/kg. A dose of 5.6 mg/kg, which did not significantly decrease locomotion, significantly reduces cocaine-seeking behavior (active lever pressing) in response to the reintroduction of drug-paired cues after a period of extinction. No dose (3, 5.6, or 10 mg/kg) produced a significant effect on a multiple schedule of self-administration with alternating availability of sucrose and cocaine as the reinforcer. These results indicate that MC-RG19 has an effect on the incentive \u2014 motivational properties of reward-paired cues.
ContributorsCarlson, Andrew Kenneth (Author) / Neisewander, Janet (Thesis director) / Gipson-Reichardt, Cassandra (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
With opioid use disorder (OUD) being an epidemic, it is important to investigate the mechanisms as to why this is so. This study established a self-administration paradigm to model and investigate the mechanisms of polysubstance, sequential use in conjunction with the analysis of withdrawal symptomatology driven by opioid withdrawal. The independent variables were dichotomized into the control group (food/cocaine) and the experimental group (oxycodone/cocaine). We hypothesized that more cocaine would be self-administered on the first day of oxycodone withdrawal. In addition, we hypothesized that somatic signs of withdrawal would increase at 16 hours post-oxycodone self-administration. Finally, we hypothesized that cocaine intake during oxycodone withdrawal would potentiate subsequent oxycodone self-administration. Our findings revealed that animals readily discriminated between the active (food or oxycodone) and inactive levers - but will however require more animals to achieve the appropriate power. Further, the average cocaine infusions across phases exhibited significance between the oxycodone/cocaine and food/cocaine group, with the average cocaine infusions being lower in food than in oxycodone-experienced animals. This implies that the exacerbation of the sequential co-use pattern in this case yields an increase in cocaine infusions that may be driven by oxycodone withdrawal. Further, to characterize withdrawal from oxycodone self-administration, somatic signs were examined at either 0 or 16 hrs following completion of oxycodone self-administration. The oxycodone/cocaine group exhibited significantly lower body temperature at 16 hrs of oxycodone withdrawal compared to 0 hrs. No differences in somatic signs of withdrawal in the food/cocaine group was found between the two timepoints. Oxycodone withdrawal was not found to potentiate any subsequent self-administration of oxycodone. Future research is needed to uncover neurobiological underpinnings of motivated polysubstance use in order to discover novel pharmacotherapeutic treatments to decrease co-use of drugs of abuse. Overall, this study is of importance as it is the first to establish a working preclinical model of a clinically-relevant pattern of polysubstance use. By doing so, it enables an exceptional opportunity to examine co-use in a highly-controlled setting.
ContributorsUlangkaya, Hanaa Corsino (Author) / Gipson-Reichardt, Cassandra (Thesis director) / Olive, M. Foster (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05