The Role of Serotonin (5-HT) in Behavioral Control: Findings from Animal Research and Clinical Implications

The neurotransmitters serotonin and dopamine both have a critical role in the underlying neurobiology of different behaviors. With focus on the interplay between dopamine and serotonin, it has been proposed that dopamine biases behavior towards habitual responding, and with serotonin offsetting this phenomenon and directing the balance toward more flexible, goal-directed responding. The present focus paper stands in close relationship to the publication by Worbe et al. (2015), which deals with the effects of acute tryptophan depletion, a neurodietary physiological method to decrease central nervous serotonin synthesis in humans for a short period of time, on the balance between hypothetical goal-directed and habitual systems. In that research, acute tryptophan depletion challenge administration and a following short-term reduction in central nervous serotonin synthesis were associated with a shift of behavioral performance towards habitual responding, providing further evidence that central nervous serotonin function modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. In the present focus paper, we discuss the findings by Worbe and colleagues in light of animal experiments as well as clinical implications and discuss potential future avenues for related research.     

A set of double-angled needle holders and long,angled tissue forceps for use in surgery of the abdomen

A set of double-angled needle holders and long, angled tissue forceps have been designed and presented for use in surgery of the abdomen. The problems of passage and control of curved needles in all directions is well recognized. The marriage of design and presentation addresses the mechanical and anatomic needs of surgeons in the pelvis, subdiaphragmatic area, and in large and obese patients. Multiple variables in use provided by these instruments, particularly when used together, enhance surgical control at problem sites.     

Childhood Primary Care Services in Wyoming

Provision of childhood primary care services and differences between types of providers (family practice physicians, pediatricians, nurse practitioners, and physicians' assistants) were explored in this study. A mail survey was conducted in Wyoming using a questionnaire based on the recommendations from the U. S. Preventive Service Task Force. Sixty-one percent of the providers returned questionnaires. While some areas of assessment, screening, and treatment/counseling services were provided at high levels, many were not. Gaps exist particularly in the areas of behavioral and lifestyle assessment and treatment/counseling. Only small differences existed between types of providers. However, nurse practitioners and pediatricians were more likely to report that they followed recommendations, while physicians' assistants were least likely to report that they followed recommendations.     

Validation of the Defining Characteristics of the Nursing Diagnosis Ineffective Airway Clearance

The investigators designed this validation study to determine the defining characteristics of the nursing diagnosis ineffective airway clearance. Using Fehring's Diagnostic Content Validity Model, 546 nurses who care for respiratory clients validated one major and 19 minor defining characteristics. Nine characteristics previously described in the literature were eliminated. Clarification of the defining characteristics of this diagnosis improves communication in practice, education and research.     

Book Review

Performance Breakthroughs for Adolescents With Learning Disabilities or ADD. G. Markel & J. Greenbaum.     

Characterization of the effects of cultured vascular cells on the activation of blood coagulation

The coagulant properties of intact bovine vascular cells (aortic endothelial and smooth muscle cells) and human vascular cells (cutaneous and foreskin microvascular cells, umbilical venous endothelium) grown in vitro were studied. Compared to nonvascular cells (fibroblasts, corneal endothelial cells, fetal lung or intestinal mucosal cells), vascular cells had little procoagulant activity. Radioimmunologic measurement of thrombin in recalcified plasma demonstrated markedly lower concentrations of thrombin in the presence of vascular endothelial and smooth muscle cells compared to corneal endothelial and fetal lung cells. The low thrombin concentrations were not a consequence of thrombin binding to the vascular cells nor were they due to accelerated thrombin inactivation by antithrombin-III or alpha 2-macroglobulin. Neither vascular cells nor the nonvascular cells promoted contact activation of plasma as measured by a sensitive specific assay for kallikrein. Studies with intact cell monolayers and purified factors VIIa and X indicated that while nonvascular cells express tissue factor activity, vascular cells do not exhibit this property. These data suggest that the nonthrombogenic nature of intact vascular cells is due to their failure to initiate contact activation and to express tissue factor activity. In addition, the primary difference in coagulant potential between vascular cells and nonvascular cells is the lack of tissue factor expression by the vascular cells.