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Modified Single Prolonged Stress Reduces Cocaine Self-Administration During Acquisition Regardless Of Rearing Environment, Rebecca S. Hofford, Mark A. Prendergast, Michael T. Bardo

Psychology Faculty Publications

Until recently, there were few rodent models available to study the interaction of post-traumatic stress disorder (PTSD) and drug taking. Like PTSD, single prolonged stress (SPS) produces hypothalamic-pituitary-adrenal (HPA) axis dysfunction and alters psychostimulant self-administration. Other stressors, such as isolation stress, also alter psychostimulant self-administration. However, it is currently unknown if isolation housing combined with SPS can alter the acquisition or maintenance of cocaine self-administration. The current study applied modified SPS (modSPS; two hours restraint immediately followed by cold swim stress) to rats raised in an isolation condition (Iso), enrichment condition (Enr), or standard condition (Std) to measure changes in …

Nmda Receptor Blockade Specifically Impedes The Acquisition Of Incentive Salience Attribution, Jonathan J. Chow, Joshua S. Beckmann

Psychology Faculty Publications

Glutamatergic signaling plays an important role in learning and memory. Using Pavlovian conditioned approach procedures, the mechanisms that drive stimulus-reward learning and memory have been investigated. However, there are instances where reward-predictive stimuli can function beyond being solely predictive and can be attributed with “motivational value” or incentive salience. Using a Pavlovian conditioned approach procedure consisting of two different but equally predictive stimuli (lever vs. tone) we investigated the role NMDA receptor function has in the attribution of incentive salience. The results revealed that the administration of MK-801, an NMDA receptor antagonist, during acquisition of Pavlovian conditioned approach promoted goal-tracking …

Effects Of Environmental Enrichment On Self-Administration Of The Short-Acting Opioid Remifentanil In Male Rats, Rebecca S. Hofford, Jonathan J. Chow, Joshua S. Beckmann, Michael T. Bardo

Psychology Faculty Publications

Background

Opioid abuse is a major problem around the world. Identifying environmental factors that contribute to opioid abuse and addiction is necessary for decreasing this epidemic. In rodents, environmental enrichment protects against the development of low dose stimulant self-administration, but studies examining the effect of enrichment and isolation (compared to standard housing) on the development of intravenous opioid self-administration have not been conducted. The present study investigated the role of environmental enrichment on self-administration of the short-acting μ-opioid remifentanil.

Methods

Rats were raised in an enriched condition (Enr), standard condition (Std), or isolated condition (Iso) beginning at 21 days of …