The TgCRND8 mouse model of Alzheimer's disease exhibits progressive cortical and hippocampal β-amyloid accumulation, resulting in plaque pathology and spatial memory impairment by 3 months of age. We tested whether TgCRND8 cognitive function is disrupted prior to the appearance of macroscopic plaques in an object recognition task. We found profound deficits in 8-week-old mice. Animals this age were not impaired on the Morris water maze task. TgCRND8 and littermate controls did not differ in their duration of object exploration or optokinetic responses. Thus, visual and motor dysfunction did not confound the phenotype. Object memory deficits point to the frontal cortex and hippocampus as early targets of functional disruption. Indeed, we observed altered levels of brain-derived neurotrophic factor (BDNF) messenger ribonucleic acid (mRNA) in these brain regions of preplaque TgCRND8 mice. Our findings suggest that object recognition provides an early index of cognitive impairment associated with amyloid exposure and reduced brain-derived neurotrophic factor expression in the TgCRND8 mouse.

The debate on pediatric vaccination policy has been characterized by the presence of two distinct coalitions: those in favor of current vaccination policies and those expressing concern about these policies. The target of these coalitions is the vaccination decision of parents. To determine their influence, we conducted four focus groups in Toronto, Canada examining parental decision-making concerning pediatric vaccination. Our focus groups consisted of both fathers and mothers and parents who fully vaccinated and those who did not. Using the Advocacy Coalition Framework as an analytic guide, we identified several themes that provided insights into how effective the two coalitions have been in conveying their viewpoints. In general, we identified a variety of levels of belief systems existing amongst parents concerned about vaccination, some more amenable to change than others. We found that the choice to not vaccinate was largely a result of concerns about safety and, to a lesser extent, about lack of effectiveness. These parental views reflected the ability of the coalition concerned about vaccination to challenge parents' trust in traditional public health sources of information. In contrast, the parental decision to vaccinate was due to recognizing the importance of preventing disease and also a consequence of not questioning recommendations from public health and physicians and feeling pressured to because of school policies. Importantly, parents who fully vaccinate appear to have weaker belief systems that are potentially susceptible to change. While current policies appear to be effective in encouraging vaccination, if trust in public health falters, many who currently support vaccination may reevaluate their position. More research needs to be conducted to identify approaches to communicate the risks and benefits of vaccination to parents.

Ever since the advent of pediatric vaccination, individuals have expressed concerns about both its risks and benefits. These concerns have once again resurfaced among some segments of the population and could potentially undermine national vaccination programs. The views of the public, however, must be considered and respected in the formulation of vaccination policy. We have conducted an analysis of the pediatric vaccination "debate" in the Canadian context. We believe that there is common ground between those who support pediatric vaccination and those who are concerned about these programs. Based on our findings, we believe that the goal of public health authorities should be to maintain trust in vaccines by continuing to meet certain reciprocal responsibilities. To do so, we recommend the following: 1) increased investment in adverse event reporting systems; 2) request for proposals for consideration of a no-fault compensation program; 3) developing pre-emptive strategies to deal with potential vaccine risks; 4) further examination of mechanisms to improve communication between physicians and parents concerned about vaccination. All of these approaches would require additional investment in pediatric vaccination. However, such an investment is easy to justify given the benefits offered by pediatric vaccination and the ramifications of failing to maintain confidence in vaccination programs or missing a vaccine-related adverse event. MeSH terms: Vaccination; pediatric; policy; adverse events; risk La traduction du résumé se trouve à la fin de l'article.