Publications by authors named "Shanna B Samels"

Background: Pituitary adenylate cyclase-activating polypeptide (PACAP) has been found to be involved in a wide range of motivated and affective behaviors. While the PACAP-38 isoform is more densely expressed than PACAP-27 in most of the brain, PACAP-27 is more highly expressed in the rodent paraventricular nucleus of the thalamus (PVT), where females also have greater expression than males. Notably, the role of PACAP-27 expression in cells of the PVT has not been explored.

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Active avoidance responses (ARs) are instrumental behaviors that prevent harm. Adaptive ARs may contribute to active coping, whereas maladaptive avoidance habits are implicated in anxiety and obsessive-compulsive disorders. The AR learning mechanism has remained elusive, as successful avoidance trials produce no obvious reinforcer.

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The hypocretins/orexins (HCRT) have been demonstrated to influence motivation for cocaine through actions on dopamine (DA) transmission. Pharmacological or genetic disruption of the hypocretin receptor 1 (Hcrtr1) reduces cocaine self-administration, blocks reinstatement of cocaine seeking, and decreases conditioned place preference for cocaine. These effects are likely mediated through actions in the ventral tegmental area (VTA) and resulting alterations in DA transmission.

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Background: While men in the United States consume more alcohol than women, rates of drinking are converging. Nevertheless, females remain underrepresented in preclinical alcohol research. Here, we examined rats' sex-related differences in patterns of ethanol (EtOH) drinking and the effects of this drinking on exploratory and anxiety-like behavior.

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In signaled active avoidance (SigAA), rats learn to suppress Pavlovian freezing and emit actions to remove threats and prevent footshocks. SigAA is critical for understanding aversively motivated instrumental behavior and anxiety-related active coping. However, with standard protocols ∼25% of rats exhibit high freezing and poor avoidance.

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