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Inactivation Of The Medial-Prefrontal Cortex Impairs Interval Timing Precision, But Not Timing Accuracy Or Scalar Timing In A Peak-Interval Procedure In Rats, Catalin V. Buhusi, Marcelo B. Reyes, Cody-Aaron Gathers, Sorinel A. Oprisan, Mona Buhusi

Psychology Faculty Publications

Motor sequence learning, planning and execution of goal-directed behaviors, and decision making rely on accurate time estimation and production of durations in the seconds-to-minutes range. The pathways involved in planning and execution of goal-directed behaviors include cortico-striato-thalamo-cortical circuitry modulated by dopaminergic inputs. A critical feature of interval timing is its scalar property, by which the precision of timing is proportional to the timed duration. We examined the role of medial prefrontal cortex (mPFC) in timing by evaluating the effect of its reversible inactivation on timing accuracy, timing precision and scalar timing. Rats were trained to time two durations in a …

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 …

Blocking Of Acquisition But Not Expression Of Conditioned Fear-Potentiated Startle By Nmda Antagonists In The Amygdala, Mindy Miserendino, Catherine B. Sananes, Kathleen R. Melia, Michael Davis

Psychology Faculty Publications

Assessed the role of N-methyl-{d}-aspartate (NMDA) receptors in the amygdala in associative fear conditioning. 132 rats were implanted with cannulae aimed at the basolateral amygdaloid nuclei, while 13 controls had cannulae aimed at the interpositus nuclei of the cerebellum. NMDA antagonists infused into the amygdala blocked the acquisition, but not the expression, of fear conditioning measured with a behavioral assay mediated by a defined neural circuit (fear-potentiation of the acoustic startle reflex). This effect showed anatomical and pharmacological specificity, and was not attributable to reduced salience of the stimuli of light or shock used in training. An NMDA-dependent process in …