Fast-scan cyclic voltammetry demonstrates that L-DOPA produces dose-dependent, regionally selective bimodal effects on striatal dopamine kinetics in vivo.

Parkinson's disease (PD) is a debilitating condition that is caused by a relatively specific degeneration of dopaminergic (DAergic) neurons of the substantia nigra pars compacta. L-DOPA was introduced as a viable treatment option for PD over 40 years ago and still remains the most common and effective therapy for PD. Though the effects of L-DOPA to augment striatal DA production are well known, little is actually known about how L-DOPA alters the kinetics of DA neurotransmission that contribute to its beneficial and adverse effects. In this study, we examined the effects of L-DOPA administration (50 mg/kg carbidopa + 0, 100, and 250 mg/kg L-DOPA) on regional electrically stimulated DA response kinetics using fast-scan cyclic voltammetry in anesthetized rats. We demonstrate that L-DOPA enhances DA release in both the dorsal striatum (D-STR) and nucleus accumbens (NAc), but surprisingly causes a delayed inhibition of release in the D-STR. In both regions, L-DOPA progressively attenuated reuptake kinetics, predominantly through a decrease in Vmax . These findings have important implications on understanding the pharmacodynamics of L-DOPA, which may be informative for understanding its therapeutic effects and also common side effects like L-DOPA-induced dyskinesias (LID). L-DOPA is commonly used to treat Parkinsonian symptoms, but little is known about how it affects presynaptic DA neurotransmission. Using in vivo fast-scan cyclic voltammetry, we show L-DOPA inhibits DA reuptake in a region-specific and dose-dependent manner, and L-DOPA has paradoxical effects on release. These findings may be important when considering mechanisms for L-DOPA's therapeutic benefits and adverse side-effects.

Visual Priming Enhances the Effects of Nonspatial Cognitive Rehabilitation Training on Spatial Learning After Experimental Traumatic Brain Injury.

Previous work demonstrates that spatial (explicit) and nonspatial (implicit) elements of place learning in the Morris water maze (MWM) task can be dissociated and examined in the context of experimental traumatic brain injury (TBI). Providing nonspatial cognitive training (CT) after injury can improve place learning compared with untrained controls. In the present study, we hypothesized that brief exposure to extra-maze cues, in conjunction with CT, may further improve MWM performance and extra-maze cue utilization compared with CT alone. Adult male Sprague-Dawley rats (n = 66) received controlled cortical impact (CCI) injury or sham surgery. Beginning day 8 postsurgery, CCI and sham rats received 6 days of no training (NT) or CT with/without brief, noncontextualized exposure to extra-maze cues (BE and CT, respectively). Acquisition (days 14-18), visible platform (VP; day 19), carryover (CO; days 20-26), and periodic probe trials were performed. Platform latencies, peripheral and target zone time allocation, and search strategies were assessed. CCI/BE rats had shorter acquisition trial latencies than CCI/NT (P < .001) and tended to have shorter latencies than CCI/CT rats (P < .10). Both BE and CT reduced peripheral zone swimming for CCI rats versus CCI/NT. CCI/BE animals increased spatial swim strategies from day 14 to day 18 relative to CCI/CT and showed similar swim strategy selection to the Sham/NT group. These data suggest that visual priming improves initial place learning in the MWM. These results support the visual priming response as another clinically relevant experimental rehabilitation construct, to use when assessing injury and treatment effects of behavioral and pharmacological therapies on cognition after TBI.

Digital storytelling: an innovative technological approach to nursing education.

This study investigated the impact of using digital stories in promoting deeper understanding in nursing students about palliative care concepts. Students (N = 134) created a 5-minute narrated digital story utilizing VoiceThread technology that synthesized and applied knowledge that had been presented in class and course readings. Postsurvey and focus group evaluation data revealed that through the writing and sharing of digital stories, students embraced the personal and complex nature of palliative care.

Collaborative strategies for teaching evidence-based practice in accelerated second-degree programs.

An important challenge for teaching in accelerated second-degree programs is how to manage essential content within a compressed curriculum format. This article describes a project that used a collaborative model for teaching evidence-based practice (EBP) in a redesigned second-degree nursing program. Instructors in two courses shared responsibility for teaching basic concepts and guiding students' implementation of EBP in a clinical setting in partnership with clinical nurses. This approach resulted in a high degree of satisfaction for students, instructors, and nursing staff in clinical agencies. The project demonstrated collaborative teaching strategies can help students achieve basic knowledge in EBP and translate that knowledge into their clinical practice. Collaboration also can achieve more efficient learning experiences, a critical element in accelerated nursing programs.

Carry-over effects of smoking cue exposure on working memory performance.

The present study investigated the effects of drug cue exposure on working memory performance in cigarette smokers. Adult smokers (N = 23) deprived for 12 hr performed a working memory task during which they were exposed to three types of task-irrelevant stimuli: Pictures containing smoking related-content, pictures devoid of smoking content, and a fixation cross. Consistent with prior research, we found that drug cue exposure affected the processing of subsequent items (i.e., carry-over effects). Specifically, we found that working memory performance was worse on trials containing neutral pictures preceded by trials containing smoking cues compared with performance on trials containing neutral pictures preceded by trials not containing smoking-related stimuli. Previously observed effects of smoking cue exposure on cognitive processing were replicated but only after removing trials subject to carry-over effects. These results replicate and extend previous research demonstrating similar effects and highlight the significant methodological and conceptual implications of carry-over effects.